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/***********************************************************
* A single header file OpenGL lightmapping library *
* https://github.com/ands/lightmapper *
* no warranty implied | use at your own risk *
* author: Andreas Mantler (ands) | last change: 10.05.2018 *
* *
* License: *
* This software is in the public domain. *
* Where that dedication is not recognized, *
* you are granted a perpetual, irrevocable license to copy *
* and modify this file however you want. *
***********************************************************/
#ifndef LIGHTMAPPER_H
#define LIGHTMAPPER_H
#ifdef __cplusplus
#define LM_DEFAULT_VALUE(value) = value
#else
#define LM_DEFAULT_VALUE(value)
#endif
#ifndef LM_CALLOC
#define LM_CALLOC(count, size) calloc(count, size)
#endif
#ifndef LM_FREE
#define LM_FREE(ptr) free(ptr)
#endif
typedef int lm_bool;
#define LM_FALSE 0
#define LM_TRUE 1
typedef int lm_type;
#define LM_NONE 0
#define LM_UNSIGNED_BYTE GL_UNSIGNED_BYTE
#define LM_UNSIGNED_SHORT GL_UNSIGNED_SHORT
#define LM_UNSIGNED_INT GL_UNSIGNED_INT
#define LM_FLOAT GL_FLOAT
typedef struct lm_context lm_context;
// creates a lightmapper instance. it can be used to render multiple lightmaps.
lm_context *lmCreate(
int hemisphereSize, // hemisphereSize: resolution of the hemisphere renderings. must be a power of two! typical: 64.
float zNear, float zFar, // zNear/zFar: hemisphere min/max draw distances.
float clearR, float clearG, float clearB, // clear color / background color / sky color.
int interpolationPasses, float interpolationThreshold, // passes: hierarchical selective interpolation passes (0-8; initial step size = 2^passes).
// threshold: error value below which lightmap pixels are interpolated instead of rendered.
// use output image from LM_DEBUG_INTERPOLATION to determine a good value.
// values around and below 0.01 are probably ok.
// the lower the value, the more hemispheres are rendered -> slower, but possibly better quality.
float cameraToSurfaceDistanceModifier LM_DEFAULT_VALUE(0.0f)); // modifier for the height of the rendered hemispheres above the surface
// -1.0f => stick to surface, 0.0f => minimum height for interpolated surface normals,
// > 0.0f => improves gradients on surfaces with interpolated normals due to the flat surface horizon,
// but may introduce other artifacts.
// optional: set material characteristics by specifying cos(theta)-dependent weights for incoming light.
typedef float (*lm_weight_func)(float cos_theta, void *userdata);
void lmSetHemisphereWeights(lm_context *ctx, lm_weight_func f, void *userdata); // precalculates weights for incoming light depending on its angle. (default: all weights are 1.0f)
// specify an output lightmap image buffer with w * h * c * sizeof(float) bytes of memory.
void lmSetTargetLightmap(lm_context *ctx, float *outLightmap, int w, int h, int c); // output HDR lightmap (linear 32bit float channels; c: 1->Greyscale, 2->Greyscale+Alpha, 3->RGB, 4->RGBA).
// set the geometry to map to the currently set target lightmap (set the target lightmap before calling this!).
void lmSetGeometry(lm_context *ctx,
const float *transformationMatrix, // 4x4 object-to-world transform for the geometry or NULL (no transformation).
lm_type positionsType, const void *positionsXYZ, int positionsStride, // triangle mesh in object space.
lm_type normalsType, const void *normalsXYZ, int normalsStride, // optional normals for the mesh in object space (Use LM_NONE type in case you only need flat surfaces).
lm_type lightmapCoordsType, const void *lightmapCoordsUV, int lightmapCoordsStride, // lightmap atlas texture coordinates for the mesh [0..1]x[0..1] (integer types are normalized to 0..1 range).
int count, lm_type indicesType LM_DEFAULT_VALUE(LM_NONE), const void *indices LM_DEFAULT_VALUE(0));// if mesh indices are used, count = number of indices else count = number of vertices.
// as long as lmBegin returns true, the scene has to be rendered with the
// returned camera and view parameters to the currently bound framebuffer.
// if lmBegin returns true, it must be followed by lmEnd after rendering!
lm_bool lmBegin(lm_context *ctx,
int* outViewport4, // output of the current viewport: { x, y, w, h }. use these to call glViewport()!
float* outView4x4, // output of the current camera view matrix.
float* outProjection4x4); // output of the current camera projection matrix.
float lmProgress(lm_context *ctx); // should only be called between lmBegin/lmEnd!
// provides the light mapping progress as a value increasing from 0.0 to 1.0.
void lmEnd(lm_context *ctx);
// destroys the lightmapper instance. should be called to free resources.
void lmDestroy(lm_context *ctx);
// image based post processing (c is the number of color channels in the image, m a channel mask for the operation)
#define LM_ALL_CHANNELS 0x0f
float lmImageMin(const float *image, int w, int h, int c, int m LM_DEFAULT_VALUE(LM_ALL_CHANNELS)); // find the minimum value (across the specified channels)
float lmImageMax(const float *image, int w, int h, int c, int m LM_DEFAULT_VALUE(LM_ALL_CHANNELS)); // find the maximum value (across the specified channels)
void lmImageAdd(float *image, int w, int h, int c, float value, int m LM_DEFAULT_VALUE(LM_ALL_CHANNELS)); // in-place add to the specified channels
void lmImageScale(float *image, int w, int h, int c, float factor, int m LM_DEFAULT_VALUE(LM_ALL_CHANNELS)); // in-place scaling of the specified channels
void lmImagePower(float *image, int w, int h, int c, float exponent, int m LM_DEFAULT_VALUE(LM_ALL_CHANNELS)); // in-place powf(v, exponent) of the specified channels (for gamma)
void lmImageDilate(const float *image, float *outImage, int w, int h, int c); // widen the populated non-zero areas by 1 pixel.
void lmImageSmooth(const float *image, float *outImage, int w, int h, int c); // simple box filter on only the non-zero values.
void lmImageDownsample(const float *image, float *outImage, int w, int h, int c); // downsamples [0..w]x[0..h] to [0..w/2]x[0..h/2] by avereging only the non-zero values
void lmImageFtoUB(const float *image, unsigned char *outImage, int w, int h, int c, float max LM_DEFAULT_VALUE(0.0f)); // casts a floating point image to an 8bit/channel image
// TGA file output helpers
lm_bool lmImageSaveTGAub(const char *filename, const unsigned char *image, int w, int h, int c);
lm_bool lmImageSaveTGAf(const char *filename, const float *image, int w, int h, int c, float max LM_DEFAULT_VALUE(0.0f));
#endif
////////////////////// END OF HEADER //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#ifdef LIGHTMAPPER_IMPLEMENTATION
#undef LIGHTMAPPER_IMPLEMENTATION
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <float.h>
#include <assert.h>
#include <limits.h>
#define LM_SWAP(type, a, b) { type tmp = (a); (a) = (b); (b) = tmp; }
#if defined(_MSC_VER) && !defined(__cplusplus)
#define inline __inline
#endif
#if defined(_MSC_VER) && (_MSC_VER <= 1700)
static inline lm_bool lm_finite(float a) { return _finite(a); }
#else
static inline lm_bool lm_finite(float a) { return isfinite(a); }
#endif
static inline int lm_mini (int a, int b) { return a < b ? a : b; }
static inline int lm_maxi (int a, int b) { return a > b ? a : b; }
static inline int lm_absi (int a ) { return a < 0 ? -a : a; }
static inline float lm_minf (float a, float b) { return a < b ? a : b; }
static inline float lm_maxf (float a, float b) { return a > b ? a : b; }
static inline float lm_absf (float a ) { return a < 0.0f ? -a : a; }
static inline float lm_pmodf (float a, float b) { return (a < 0.0f ? 1.0f : 0.0f) + (float)fmod(a, b); } // positive mod
typedef struct lm_ivec2 { int x, y; } lm_ivec2;
static inline lm_ivec2 lm_i2 (int x, int y) { lm_ivec2 v = { x, y }; return v; }
typedef struct lm_vec2 { float x, y; } lm_vec2;
static inline lm_vec2 lm_v2i (int x, int y) { lm_vec2 v = { (float)x, (float)y }; return v; }
static inline lm_vec2 lm_v2 (float x, float y) { lm_vec2 v = { x, y }; return v; }
static inline lm_vec2 lm_negate2 (lm_vec2 a ) { return lm_v2(-a.x, -a.y); }
static inline lm_vec2 lm_add2 (lm_vec2 a, lm_vec2 b) { return lm_v2(a.x + b.x, a.y + b.y); }
static inline lm_vec2 lm_sub2 (lm_vec2 a, lm_vec2 b) { return lm_v2(a.x - b.x, a.y - b.y); }
static inline lm_vec2 lm_mul2 (lm_vec2 a, lm_vec2 b) { return lm_v2(a.x * b.x, a.y * b.y); }
static inline lm_vec2 lm_scale2 (lm_vec2 a, float b) { return lm_v2(a.x * b, a.y * b); }
static inline lm_vec2 lm_div2 (lm_vec2 a, float b) { return lm_scale2(a, 1.0f / b); }
static inline lm_vec2 lm_pmod2 (lm_vec2 a, float b) { return lm_v2(lm_pmodf(a.x, b), lm_pmodf(a.y, b)); }
static inline lm_vec2 lm_min2 (lm_vec2 a, lm_vec2 b) { return lm_v2(lm_minf(a.x, b.x), lm_minf(a.y, b.y)); }
static inline lm_vec2 lm_max2 (lm_vec2 a, lm_vec2 b) { return lm_v2(lm_maxf(a.x, b.x), lm_maxf(a.y, b.y)); }
static inline lm_vec2 lm_abs2 (lm_vec2 a ) { return lm_v2(lm_absf(a.x), lm_absf(a.y)); }
static inline lm_vec2 lm_floor2 (lm_vec2 a ) { return lm_v2(floorf(a.x), floorf(a.y)); }
static inline lm_vec2 lm_ceil2 (lm_vec2 a ) { return lm_v2(ceilf (a.x), ceilf (a.y)); }
static inline float lm_dot2 (lm_vec2 a, lm_vec2 b) { return a.x * b.x + a.y * b.y; }
static inline float lm_cross2 (lm_vec2 a, lm_vec2 b) { return a.x * b.y - a.y * b.x; } // pseudo cross product
static inline float lm_length2sq (lm_vec2 a ) { return a.x * a.x + a.y * a.y; }
static inline float lm_length2 (lm_vec2 a ) { return sqrtf(lm_length2sq(a)); }
static inline lm_vec2 lm_normalize2(lm_vec2 a ) { return lm_div2(a, lm_length2(a)); }
static inline lm_bool lm_finite2 (lm_vec2 a ) { return lm_finite(a.x) && lm_finite(a.y); }
typedef struct lm_vec3 { float x, y, z; } lm_vec3;
static inline lm_vec3 lm_v3 (float x, float y, float z) { lm_vec3 v = { x, y, z }; return v; }
static inline lm_vec3 lm_negate3 (lm_vec3 a ) { return lm_v3(-a.x, -a.y, -a.z); }
static inline lm_vec3 lm_add3 (lm_vec3 a, lm_vec3 b) { return lm_v3(a.x + b.x, a.y + b.y, a.z + b.z); }
static inline lm_vec3 lm_sub3 (lm_vec3 a, lm_vec3 b) { return lm_v3(a.x - b.x, a.y - b.y, a.z - b.z); }
static inline lm_vec3 lm_mul3 (lm_vec3 a, lm_vec3 b) { return lm_v3(a.x * b.x, a.y * b.y, a.z * b.z); }
static inline lm_vec3 lm_scale3 (lm_vec3 a, float b) { return lm_v3(a.x * b, a.y * b, a.z * b); }
static inline lm_vec3 lm_div3 (lm_vec3 a, float b) { return lm_scale3(a, 1.0f / b); }
static inline lm_vec3 lm_pmod3 (lm_vec3 a, float b) { return lm_v3(lm_pmodf(a.x, b), lm_pmodf(a.y, b), lm_pmodf(a.z, b)); }
static inline lm_vec3 lm_min3 (lm_vec3 a, lm_vec3 b) { return lm_v3(lm_minf(a.x, b.x), lm_minf(a.y, b.y), lm_minf(a.z, b.z)); }
static inline lm_vec3 lm_max3 (lm_vec3 a, lm_vec3 b) { return lm_v3(lm_maxf(a.x, b.x), lm_maxf(a.y, b.y), lm_maxf(a.z, b.z)); }
static inline lm_vec3 lm_abs3 (lm_vec3 a ) { return lm_v3(lm_absf(a.x), lm_absf(a.y), lm_absf(a.z)); }
static inline lm_vec3 lm_floor3 (lm_vec3 a ) { return lm_v3(floorf(a.x), floorf(a.y), floorf(a.z)); }
static inline lm_vec3 lm_ceil3 (lm_vec3 a ) { return lm_v3(ceilf (a.x), ceilf (a.y), ceilf (a.z)); }
static inline float lm_dot3 (lm_vec3 a, lm_vec3 b) { return a.x * b.x + a.y * b.y + a.z * b.z; }
static inline lm_vec3 lm_cross3 (lm_vec3 a, lm_vec3 b) { return lm_v3(a.y * b.z - b.y * a.z, a.z * b.x - b.z * a.x, a.x * b.y - b.x * a.y); }
static inline float lm_length3sq (lm_vec3 a ) { return a.x * a.x + a.y * a.y + a.z * a.z; }
static inline float lm_length3 (lm_vec3 a ) { return sqrtf(lm_length3sq(a)); }
static inline lm_vec3 lm_normalize3(lm_vec3 a ) { return lm_div3(a, lm_length3(a)); }
static inline lm_bool lm_finite3 (lm_vec3 a ) { return lm_finite(a.x) && lm_finite(a.y) && lm_finite(a.z); }
static lm_vec2 lm_toBarycentric(lm_vec2 p1, lm_vec2 p2, lm_vec2 p3, lm_vec2 p)
{
// http://www.blackpawn.com/texts/pointinpoly/
// Compute vectors
lm_vec2 v0 = lm_sub2(p3, p1);
lm_vec2 v1 = lm_sub2(p2, p1);
lm_vec2 v2 = lm_sub2(p, p1);
// Compute dot products
float dot00 = lm_dot2(v0, v0);
float dot01 = lm_dot2(v0, v1);
float dot02 = lm_dot2(v0, v2);
float dot11 = lm_dot2(v1, v1);
float dot12 = lm_dot2(v1, v2);
// Compute barycentric coordinates
float invDenom = 1.0f / (dot00 * dot11 - dot01 * dot01);
float u = (dot11 * dot02 - dot01 * dot12) * invDenom;
float v = (dot00 * dot12 - dot01 * dot02) * invDenom;
return lm_v2(u, v);
}
static inline int lm_leftOf(lm_vec2 a, lm_vec2 b, lm_vec2 c)
{
float x = lm_cross2(lm_sub2(b, a), lm_sub2(c, b));
return x < 0 ? -1 : x > 0;
}
static lm_bool lm_lineIntersection(lm_vec2 x0, lm_vec2 x1, lm_vec2 y0, lm_vec2 y1, lm_vec2* res)
{
lm_vec2 dx = lm_sub2(x1, x0);
lm_vec2 dy = lm_sub2(y1, y0);
lm_vec2 d = lm_sub2(x0, y0);
float dyx = lm_cross2(dy, dx);
if (dyx == 0.0f)
return LM_FALSE;
dyx = lm_cross2(d, dx) / dyx;
if (dyx <= 0 || dyx >= 1)
return LM_FALSE;
res->x = y0.x + dyx * dy.x;
res->y = y0.y + dyx * dy.y;
return LM_TRUE;
}
// this modifies the poly array! the poly array must be big enough to hold the result!
// res must be big enough to hold the result!
static int lm_convexClip(lm_vec2 *poly, int nPoly, const lm_vec2 *clip, int nClip, lm_vec2 *res)
{
int nRes = nPoly;
int dir = lm_leftOf(clip[0], clip[1], clip[2]);
for (int i = 0, j = nClip - 1; i < nClip && nRes; j = i++)
{
if (i != 0)
for (nPoly = 0; nPoly < nRes; nPoly++)
poly[nPoly] = res[nPoly];
nRes = 0;
lm_vec2 v0 = poly[nPoly - 1];
int side0 = lm_leftOf(clip[j], clip[i], v0);
if (side0 != -dir)
res[nRes++] = v0;
for (int k = 0; k < nPoly; k++)
{
lm_vec2 v1 = poly[k], x;
int side1 = lm_leftOf(clip[j], clip[i], v1);
if (side0 + side1 == 0 && side0 && lm_lineIntersection(clip[j], clip[i], v0, v1, &x))
res[nRes++] = x;
if (k == nPoly - 1)
break;
if (side1 != -dir)
res[nRes++] = v1;
v0 = v1;
side0 = side1;
}
}
return nRes;
}
struct lm_context
{
struct
{
const float *modelMatrix;
float normalMatrix[9];
const unsigned char *positions;
lm_type positionsType;
int positionsStride;
const unsigned char *normals;
lm_type normalsType;
int normalsStride;
const unsigned char *uvs;
lm_type uvsType;
int uvsStride;
const unsigned char *indices;
lm_type indicesType;
unsigned int count;
} mesh;
struct
{
int pass;
int passCount;
struct
{
unsigned int baseIndex;
lm_vec3 p[3];
lm_vec3 n[3];
lm_vec2 uv[3];
} triangle;
struct
{
int minx, miny;
int maxx, maxy;
int x, y;
} rasterizer;
struct
{
lm_vec3 position;
lm_vec3 direction;
lm_vec3 up;
} sample;
struct
{
int side;
} hemisphere;
} meshPosition;
struct
{
int width;
int height;
int channels;
float *data;
#ifdef LM_DEBUG_INTERPOLATION
unsigned char *debug;
#endif
} lightmap;
struct
{
unsigned int size;
float zNear, zFar;
float cameraToSurfaceDistanceModifier;
struct { float r, g, b; } clearColor;
unsigned int fbHemiCountX;
unsigned int fbHemiCountY;
unsigned int fbHemiIndex;
lm_ivec2 *fbHemiToLightmapLocation;
GLuint fbTexture[2];
GLuint fb[2];
GLuint fbDepth;
GLuint vao;
struct
{
GLuint programID;
GLuint hemispheresTextureID;
GLuint weightsTextureID;
GLuint weightsTexture;
} firstPass;
struct
{
GLuint programID;
GLuint hemispheresTextureID;
} downsamplePass;
struct
{
GLuint texture;
lm_ivec2 writePosition;
lm_ivec2 *toLightmapLocation;
} storage;
} hemisphere;
float interpolationThreshold;
};
// pass order of one 4x4 interpolation patch for two interpolation steps (and the next neighbors right of/below it)
// 0 4 1 4 0
// 5 6 5 6 5
// 2 4 3 4 2
// 5 6 5 6 5
// 0 4 1 4 0
static unsigned int lm_passStepSize(lm_context *ctx)
{
unsigned int shift = ctx->meshPosition.passCount / 3 - (ctx->meshPosition.pass - 1) / 3;
unsigned int step = (1 << shift);
assert(step > 0);
return step;
}
static unsigned int lm_passOffsetX(lm_context *ctx)
{
if (!ctx->meshPosition.pass)
return 0;
int passType = (ctx->meshPosition.pass - 1) % 3;
unsigned int halfStep = lm_passStepSize(ctx) >> 1;
return passType != 1 ? halfStep : 0;
}
static unsigned int lm_passOffsetY(lm_context *ctx)
{
if (!ctx->meshPosition.pass)
return 0;
int passType = (ctx->meshPosition.pass - 1) % 3;
unsigned int halfStep = lm_passStepSize(ctx) >> 1;
return passType != 0 ? halfStep : 0;
}
static lm_bool lm_hasConservativeTriangleRasterizerFinished(lm_context *ctx)
{
return ctx->meshPosition.rasterizer.y >= ctx->meshPosition.rasterizer.maxy;
}
static void lm_moveToNextPotentialConservativeTriangleRasterizerPosition(lm_context *ctx)
{
unsigned int step = lm_passStepSize(ctx);
ctx->meshPosition.rasterizer.x += step;
while (ctx->meshPosition.rasterizer.x >= ctx->meshPosition.rasterizer.maxx)
{
ctx->meshPosition.rasterizer.x = ctx->meshPosition.rasterizer.minx + lm_passOffsetX(ctx);
ctx->meshPosition.rasterizer.y += step;
if (lm_hasConservativeTriangleRasterizerFinished(ctx))
break;
}
}
static float *lm_getLightmapPixel(lm_context *ctx, int x, int y)
{
assert(x >= 0 && x < ctx->lightmap.width && y >= 0 && y < ctx->lightmap.height);
return ctx->lightmap.data + (y * ctx->lightmap.width + x) * ctx->lightmap.channels;
}
static void lm_setLightmapPixel(lm_context *ctx, int x, int y, float *in)
{
assert(x >= 0 && x < ctx->lightmap.width && y >= 0 && y < ctx->lightmap.height);
float *p = ctx->lightmap.data + (y * ctx->lightmap.width + x) * ctx->lightmap.channels;
for (int j = 0; j < ctx->lightmap.channels; j++)
*p++ = *in++;
}
#define lm_baseAngle 0.1f
static const float lm_baseAngles[3][3] = {
{ lm_baseAngle, lm_baseAngle + 1.0f / 3.0f, lm_baseAngle + 2.0f / 3.0f },
{ lm_baseAngle + 1.0f / 3.0f, lm_baseAngle + 2.0f / 3.0f, lm_baseAngle },
{ lm_baseAngle + 2.0f / 3.0f, lm_baseAngle, lm_baseAngle + 1.0f / 3.0f }
};
static lm_bool lm_trySamplingConservativeTriangleRasterizerPosition(lm_context *ctx)
{
if (lm_hasConservativeTriangleRasterizerFinished(ctx))
return LM_FALSE;
// check if lightmap pixel was already set
float *pixelValue = lm_getLightmapPixel(ctx, ctx->meshPosition.rasterizer.x, ctx->meshPosition.rasterizer.y);
for (int j = 0; j < ctx->lightmap.channels; j++)
if (pixelValue[j] != 0.0f)
return LM_FALSE;
// try calculating centroid by clipping the pixel against the triangle
lm_vec2 pixel[16];
pixel[0] = lm_v2i(ctx->meshPosition.rasterizer.x, ctx->meshPosition.rasterizer.y);
pixel[1] = lm_v2i(ctx->meshPosition.rasterizer.x + 1, ctx->meshPosition.rasterizer.y);
pixel[2] = lm_v2i(ctx->meshPosition.rasterizer.x + 1, ctx->meshPosition.rasterizer.y + 1);
pixel[3] = lm_v2i(ctx->meshPosition.rasterizer.x, ctx->meshPosition.rasterizer.y + 1);
lm_vec2 res[16];
int nRes = lm_convexClip(pixel, 4, ctx->meshPosition.triangle.uv, 3, res);
if (nRes == 0)
return LM_FALSE; // nothing left
// calculate centroid position and area
lm_vec2 centroid = res[0];
float area = res[nRes - 1].x * res[0].y - res[nRes - 1].y * res[0].x;
for (int i = 1; i < nRes; i++)
{
centroid = lm_add2(centroid, res[i]);
area += res[i - 1].x * res[i].y - res[i - 1].y * res[i].x;
}
centroid = lm_div2(centroid, (float)nRes);
area = lm_absf(area / 2.0f);
if (area <= 0.0f)
return LM_FALSE; // no area left
// calculate barycentric coords
lm_vec2 uv = lm_toBarycentric(
ctx->meshPosition.triangle.uv[0],
ctx->meshPosition.triangle.uv[1],
ctx->meshPosition.triangle.uv[2],
centroid);
if (!lm_finite2(uv))
return LM_FALSE; // degenerate
// try to interpolate color from neighbors:
if (ctx->meshPosition.pass > 0)
{
float *neighbors[4];
int neighborCount = 0;
int neighborsExpected = 0;
int d = (int)lm_passStepSize(ctx) / 2;
int dirs = ((ctx->meshPosition.pass - 1) % 3) + 1;
if (dirs & 1) // check x-neighbors with distance d
{
neighborsExpected += 2;
if (ctx->meshPosition.rasterizer.x - d >= ctx->meshPosition.rasterizer.minx &&
ctx->meshPosition.rasterizer.x + d <= ctx->meshPosition.rasterizer.maxx)
{
neighbors[neighborCount++] = lm_getLightmapPixel(ctx, ctx->meshPosition.rasterizer.x - d, ctx->meshPosition.rasterizer.y);
neighbors[neighborCount++] = lm_getLightmapPixel(ctx, ctx->meshPosition.rasterizer.x + d, ctx->meshPosition.rasterizer.y);
}
}
if (dirs & 2) // check y-neighbors with distance d
{
neighborsExpected += 2;
if (ctx->meshPosition.rasterizer.y - d >= ctx->meshPosition.rasterizer.miny &&
ctx->meshPosition.rasterizer.y + d <= ctx->meshPosition.rasterizer.maxy)
{
neighbors[neighborCount++] = lm_getLightmapPixel(ctx, ctx->meshPosition.rasterizer.x, ctx->meshPosition.rasterizer.y - d);
neighbors[neighborCount++] = lm_getLightmapPixel(ctx, ctx->meshPosition.rasterizer.x, ctx->meshPosition.rasterizer.y + d);
}
}
if (neighborCount == neighborsExpected) // are all interpolation neighbors available?
{
// calculate average neighbor pixel value
float avg[4] = { 0 };
for (int i = 0; i < neighborCount; i++)
for (int j = 0; j < ctx->lightmap.channels; j++)
avg[j] += neighbors[i][j];
float ni = 1.0f / neighborCount;
for (int j = 0; j < ctx->lightmap.channels; j++)
avg[j] *= ni;
// check if error from average pixel to neighbors is above the interpolation threshold
lm_bool interpolate = LM_TRUE;
for (int i = 0; i < neighborCount; i++)
{
lm_bool zero = LM_TRUE;
for (int j = 0; j < ctx->lightmap.channels; j++)
{
if (neighbors[i][j] != 0.0f)
zero = LM_FALSE;
if (fabs(neighbors[i][j] - avg[j]) > ctx->interpolationThreshold)
interpolate = LM_FALSE;
}
if (zero)
interpolate = LM_FALSE;
if (!interpolate)
break;
}
// set interpolated value and return if interpolation is acceptable
if (interpolate)
{
lm_setLightmapPixel(ctx, ctx->meshPosition.rasterizer.x, ctx->meshPosition.rasterizer.y, avg);
#ifdef LM_DEBUG_INTERPOLATION
// set interpolated pixel to green in debug output
ctx->lightmap.debug[(ctx->meshPosition.rasterizer.y * ctx->lightmap.width + ctx->meshPosition.rasterizer.x) * 3 + 1] = 255;
#endif
return LM_FALSE;
}
}
}
// could not interpolate. must render a hemisphere.
// calculate 3D sample position and orientation
lm_vec3 p0 = ctx->meshPosition.triangle.p[0];
lm_vec3 p1 = ctx->meshPosition.triangle.p[1];
lm_vec3 p2 = ctx->meshPosition.triangle.p[2];
lm_vec3 v1 = lm_sub3(p1, p0);
lm_vec3 v2 = lm_sub3(p2, p0);
ctx->meshPosition.sample.position = lm_add3(p0, lm_add3(lm_scale3(v2, uv.x), lm_scale3(v1, uv.y)));
lm_vec3 n0 = ctx->meshPosition.triangle.n[0];
lm_vec3 n1 = ctx->meshPosition.triangle.n[1];
lm_vec3 n2 = ctx->meshPosition.triangle.n[2];
lm_vec3 nv1 = lm_sub3(n1, n0);
lm_vec3 nv2 = lm_sub3(n2, n0);
ctx->meshPosition.sample.direction = lm_normalize3(lm_add3(n0, lm_add3(lm_scale3(nv2, uv.x), lm_scale3(nv1, uv.y))));
ctx->meshPosition.sample.direction = lm_normalize3(ctx->meshPosition.sample.direction);
float cameraToSurfaceDistance = (1.0f + ctx->hemisphere.cameraToSurfaceDistanceModifier) * ctx->hemisphere.zNear * sqrtf(2.0f);
ctx->meshPosition.sample.position = lm_add3(ctx->meshPosition.sample.position, lm_scale3(ctx->meshPosition.sample.direction, cameraToSurfaceDistance));
if (!lm_finite3(ctx->meshPosition.sample.position) ||
!lm_finite3(ctx->meshPosition.sample.direction) ||
lm_length3sq(ctx->meshPosition.sample.direction) < 0.5f) // don't allow 0.0f. should always be ~1.0f
return LM_FALSE;
lm_vec3 up = lm_v3(0.0f, 1.0f, 0.0f);
if (lm_absf(lm_dot3(up, ctx->meshPosition.sample.direction)) > 0.8f)
up = lm_v3(0.0f, 0.0f, 1.0f);
#if 0
// triangle-consistent up vector
ctx->meshPosition.sample.up = lm_normalize3(lm_cross3(up, ctx->meshPosition.sample.direction));
return LM_TRUE;
#else
// "randomized" rotation with pattern
lm_vec3 side = lm_normalize3(lm_cross3(up, ctx->meshPosition.sample.direction));
up = lm_normalize3(lm_cross3(side, ctx->meshPosition.sample.direction));
int rx = ctx->meshPosition.rasterizer.x % 3;
int ry = ctx->meshPosition.rasterizer.y % 3;
static const float lm_pi = 3.14159265358979f;
float phi = 2.0f * lm_pi * lm_baseAngles[ry][rx] + 0.1f * ((float)rand() / (float)RAND_MAX);
ctx->meshPosition.sample.up = lm_normalize3(lm_add3(lm_scale3(side, cosf(phi)), lm_scale3(up, sinf(phi))));
return LM_TRUE;
#endif
}
// returns true if a sampling position was found and
// false if we finished rasterizing the current triangle
static lm_bool lm_findFirstConservativeTriangleRasterizerPosition(lm_context *ctx)
{
while (!lm_trySamplingConservativeTriangleRasterizerPosition(ctx))
{
lm_moveToNextPotentialConservativeTriangleRasterizerPosition(ctx);
if (lm_hasConservativeTriangleRasterizerFinished(ctx))
return LM_FALSE;
}
return LM_TRUE;
}
static lm_bool lm_findNextConservativeTriangleRasterizerPosition(lm_context *ctx)
{
lm_moveToNextPotentialConservativeTriangleRasterizerPosition(ctx);
return lm_findFirstConservativeTriangleRasterizerPosition(ctx);
}
static void lm_integrateHemisphereBatch(lm_context *ctx)
{
if (!ctx->hemisphere.fbHemiIndex)
return; // nothing to do
glDisable(GL_DEPTH_TEST);
glBindVertexArray(ctx->hemisphere.vao);
int fbRead = 0;
int fbWrite = 1;
// weighted downsampling pass
int outHemiSize = ctx->hemisphere.size / 2;
glBindFramebuffer(GL_FRAMEBUFFER, ctx->hemisphere.fb[fbWrite]);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, ctx->hemisphere.fbTexture[fbWrite], 0);
glViewport(0, 0, outHemiSize * ctx->hemisphere.fbHemiCountX, outHemiSize * ctx->hemisphere.fbHemiCountY);
glUseProgram(ctx->hemisphere.firstPass.programID);
glUniform1i(ctx->hemisphere.firstPass.hemispheresTextureID, 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, ctx->hemisphere.fbTexture[fbRead]);
glUniform1i(ctx->hemisphere.firstPass.weightsTextureID, 1);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, ctx->hemisphere.firstPass.weightsTexture);
glActiveTexture(GL_TEXTURE0);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
//glBindTexture(GL_TEXTURE_2D, 0);
#if 0
// debug output
int w = outHemiSize * ctx->hemisphere.fbHemiCountX, h = outHemiSize * ctx->hemisphere.fbHemiCountY;
glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
glBindFramebuffer(GL_READ_FRAMEBUFFER, ctx->hemisphere.fb[fbWrite]);
glReadBuffer(GL_COLOR_ATTACHMENT0);
float *image = new float[3 * w * h];
glReadPixels(0, 0, w, h, GL_RGB, GL_FLOAT, image);
lmImageSaveTGAf("firstpass.png", image, w, h, 3);
delete[] image;
#endif
// downsampling passes
glUseProgram(ctx->hemisphere.downsamplePass.programID);
glUniform1i(ctx->hemisphere.downsamplePass.hemispheresTextureID, 0);
while (outHemiSize > 1)
{
LM_SWAP(int, fbRead, fbWrite);
outHemiSize /= 2;
glBindFramebuffer(GL_FRAMEBUFFER, ctx->hemisphere.fb[fbWrite]);
glViewport(0, 0, outHemiSize * ctx->hemisphere.fbHemiCountX, outHemiSize * ctx->hemisphere.fbHemiCountY);
glBindTexture(GL_TEXTURE_2D, ctx->hemisphere.fbTexture[fbRead]);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
//glBindTexture(GL_TEXTURE_2D, 0);
}
// copy results to storage texture
glBindTexture(GL_TEXTURE_2D, ctx->hemisphere.storage.texture);
glCopyTexSubImage2D(GL_TEXTURE_2D, 0,
ctx->hemisphere.storage.writePosition.x, ctx->hemisphere.storage.writePosition.y,
0, 0, ctx->hemisphere.fbHemiCountX, ctx->hemisphere.fbHemiCountY);
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glBindVertexArray(0);
glEnable(GL_DEPTH_TEST);
// copy position mapping to storage
for (unsigned int y = 0; y < ctx->hemisphere.fbHemiCountY; y++)
{
int sy = ctx->hemisphere.storage.writePosition.y + y;
for (unsigned int x = 0; x < ctx->hemisphere.fbHemiCountX; x++)
{
int sx = ctx->hemisphere.storage.writePosition.x + x;
unsigned int hemiIndex = y * ctx->hemisphere.fbHemiCountX + x;
if (hemiIndex >= ctx->hemisphere.fbHemiIndex)
ctx->hemisphere.storage.toLightmapLocation[sy * ctx->lightmap.width + sx] = lm_i2(-1, -1);
else
ctx->hemisphere.storage.toLightmapLocation[sy * ctx->lightmap.width + sx] = ctx->hemisphere.fbHemiToLightmapLocation[hemiIndex];
}
}
// advance storage texture write position
ctx->hemisphere.storage.writePosition.x += ctx->hemisphere.fbHemiCountX;
if (ctx->hemisphere.storage.writePosition.x + (int)ctx->hemisphere.fbHemiCountX > ctx->lightmap.width)
{
ctx->hemisphere.storage.writePosition.x = 0;
ctx->hemisphere.storage.writePosition.y += ctx->hemisphere.fbHemiCountY;
assert(ctx->hemisphere.storage.writePosition.y + (int)ctx->hemisphere.fbHemiCountY < ctx->lightmap.height);
}
ctx->hemisphere.fbHemiIndex = 0;
}
static void lm_writeResultsToLightmap(lm_context *ctx)
{
// do the GPU->CPU transfer of downsampled hemispheres
float *hemi = (float*)LM_CALLOC(ctx->lightmap.width * ctx->lightmap.height, 4 * sizeof(float));
glBindTexture(GL_TEXTURE_2D, ctx->hemisphere.storage.texture);
glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_FLOAT, hemi);
// write results to lightmap texture
for (int y = 0; y < ctx->hemisphere.storage.writePosition.y + (int)ctx->hemisphere.fbHemiCountY; y++)
{
for (int x = 0; x < ctx->lightmap.width; x++)
{
lm_ivec2 lmUV = ctx->hemisphere.storage.toLightmapLocation[y * ctx->lightmap.width + x];
if (lmUV.x >= 0)
{
float *c = hemi + (y * ctx->lightmap.width + x) * 4;
float validity = c[3];
float *lm = ctx->lightmap.data + (lmUV.y * ctx->lightmap.width + lmUV.x) * ctx->lightmap.channels;
if (!lm[0] && validity > 0.9)
{
float scale = 1.0f / validity;
switch (ctx->lightmap.channels)
{
case 1:
lm[0] = lm_maxf((c[0] + c[1] + c[2]) * scale / 3.0f, FLT_MIN);
break;
case 2:
lm[0] = lm_maxf((c[0] + c[1] + c[2]) * scale / 3.0f, FLT_MIN);
lm[1] = 1.0f; // do we want to support this format?
break;
case 3:
lm[0] = lm_maxf(c[0] * scale, FLT_MIN);
lm[1] = lm_maxf(c[1] * scale, FLT_MIN);
lm[2] = lm_maxf(c[2] * scale, FLT_MIN);
break;
case 4:
lm[0] = lm_maxf(c[0] * scale, FLT_MIN);
lm[1] = lm_maxf(c[1] * scale, FLT_MIN);
lm[2] = lm_maxf(c[2] * scale, FLT_MIN);
lm[3] = 1.0f;
break;
default:
assert(LM_FALSE);
break;
}
#ifdef LM_DEBUG_INTERPOLATION
// set sampled pixel to red in debug output
ctx->lightmap.debug[(lmUV.y * ctx->lightmap.width + lmUV.x) * 3 + 0] = 255;
#endif
}
}
ctx->hemisphere.storage.toLightmapLocation[y * ctx->lightmap.width + x].x = -1; // reset
}
}
LM_FREE(hemi);
ctx->hemisphere.storage.writePosition = lm_i2(0, 0);
}
static void lm_setView(
int* viewport, int x, int y, int w, int h,
float* view, lm_vec3 pos, lm_vec3 dir, lm_vec3 up,
float* proj, float l, float r, float b, float t, float n, float f)
{
// viewport
viewport[0] = x; viewport[1] = y; viewport[2] = w; viewport[3] = h;
// view matrix: lookAt(pos, pos + dir, up)
lm_vec3 side = lm_cross3(dir, up);
//up = cross(side, dir);
dir = lm_negate3(dir); pos = lm_negate3(pos);
view[ 0] = side.x; view[ 1] = up.x; view[ 2] = dir.x; view[ 3] = 0.0f;
view[ 4] = side.y; view[ 5] = up.y; view[ 6] = dir.y; view[ 7] = 0.0f;
view[ 8] = side.z; view[ 9] = up.z; view[10] = dir.z; view[11] = 0.0f;
view[12] = lm_dot3(side, pos); view[13] = lm_dot3(up, pos); view[14] = lm_dot3(dir, pos); view[15] = 1.0f;
// projection matrix: frustum(l, r, b, t, n, f)
float ilr = 1.0f / (r - l), ibt = 1.0f / (t - b), ninf = -1.0f / (f - n), n2 = 2.0f * n;
proj[ 0] = n2 * ilr; proj[ 1] = 0.0f; proj[ 2] = 0.0f; proj[ 3] = 0.0f;
proj[ 4] = 0.0f; proj[ 5] = n2 * ibt; proj[ 6] = 0.0f; proj[ 7] = 0.0f;
proj[ 8] = (r + l) * ilr; proj[ 9] = (t + b) * ibt; proj[10] = (f + n) * ninf; proj[11] = -1.0f;
proj[12] = 0.0f; proj[13] = 0.0f; proj[14] = f * n2 * ninf; proj[15] = 0.0f;
}
// returns true if a hemisphere side was prepared for rendering and
// false if we finished the current hemisphere
static lm_bool lm_beginSampleHemisphere(lm_context *ctx, int* viewport, float* view, float* proj)
{
if (ctx->meshPosition.hemisphere.side >= 5)
return LM_FALSE;
if (ctx->meshPosition.hemisphere.side == 0)
{
// prepare hemisphere
glBindFramebuffer(GL_FRAMEBUFFER, ctx->hemisphere.fb[0]);
if (ctx->hemisphere.fbHemiIndex == 0)
{
// prepare hemisphere batch
glClearColor( // clear to valid background pixels!
ctx->hemisphere.clearColor.r,
ctx->hemisphere.clearColor.g,
ctx->hemisphere.clearColor.b, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
ctx->hemisphere.fbHemiToLightmapLocation[ctx->hemisphere.fbHemiIndex] =
lm_i2(ctx->meshPosition.rasterizer.x, ctx->meshPosition.rasterizer.y);
}
// find the target position in the batch
int x = (ctx->hemisphere.fbHemiIndex % ctx->hemisphere.fbHemiCountX) * ctx->hemisphere.size * 3;
int y = (ctx->hemisphere.fbHemiIndex / ctx->hemisphere.fbHemiCountX) * ctx->hemisphere.size;
int size = ctx->hemisphere.size;
float zNear = ctx->hemisphere.zNear;
float zFar = ctx->hemisphere.zFar;
lm_vec3 pos = ctx->meshPosition.sample.position;
lm_vec3 dir = ctx->meshPosition.sample.direction;
lm_vec3 up = ctx->meshPosition.sample.up;
lm_vec3 right = lm_cross3(dir, up);
// find the view parameters of the hemisphere side that we will render next
// hemisphere layout in the framebuffer:
// +-------+---+---+-------+
// | | | | D |
// | C | R | L +-------+
// | | | | U |
// +-------+---+---+-------+
switch (ctx->meshPosition.hemisphere.side)
{
case 0: // center
lm_setView(viewport, x, y, size, size,
view, pos, dir, up,
proj, -zNear, zNear, -zNear, zNear, zNear, zFar);
break;
case 1: // right
lm_setView(viewport, size + x, y, size / 2, size,
view, pos, right, up,
proj, -zNear, 0.0f, -zNear, zNear, zNear, zFar);
break;
case 2: // left
lm_setView(viewport, size + x + size / 2, y, size / 2, size,
view, pos, lm_negate3(right), up,
proj, 0.0f, zNear, -zNear, zNear, zNear, zFar);
break;
case 3: // down
lm_setView(viewport, 2 * size + x, y + size / 2, size, size / 2,
view, pos, lm_negate3(up), dir,
proj, -zNear, zNear, 0.0f, zNear, zNear, zFar);
break;
case 4: // up
lm_setView(viewport, 2 * size + x, y, size, size / 2,
view, pos, up, lm_negate3(dir),
proj, -zNear, zNear, -zNear, 0.0f, zNear, zFar);
break;
default:
assert(LM_FALSE);
break;
}
return LM_TRUE;
}
static void lm_endSampleHemisphere(lm_context *ctx)
{
if (++ctx->meshPosition.hemisphere.side == 5)
{
// finish hemisphere
glBindFramebuffer(GL_FRAMEBUFFER, 0);
if (++ctx->hemisphere.fbHemiIndex == ctx->hemisphere.fbHemiCountX * ctx->hemisphere.fbHemiCountY)
{
// downsample new hemisphere batch and store the results
lm_integrateHemisphereBatch(ctx);
}
}
}
static void lm_inverseTranspose(const float *m44, float *n33)
{
if (!m44)
{
n33[0] = 1.0f; n33[1] = 0.0f; n33[2] = 0.0f;
n33[3] = 0.0f; n33[4] = 1.0f; n33[5] = 0.0f;
n33[6] = 0.0f; n33[7] = 0.0f; n33[8] = 1.0f;
return;
}
float determinant = m44[ 0] * (m44[ 5] * m44[10] - m44[ 9] * m44[ 6])
- m44[ 1] * (m44[ 4] * m44[10] - m44[ 6] * m44[ 8])
+ m44[ 2] * (m44[ 4] * m44[ 9] - m44[ 5] * m44[ 8]);
assert(fabs(determinant) > FLT_EPSILON);
float rcpDeterminant = 1.0f / determinant;
n33[0] = (m44[ 5] * m44[10] - m44[ 9] * m44[ 6]) * rcpDeterminant;
n33[3] = -(m44[ 1] * m44[10] - m44[ 2] * m44[ 9]) * rcpDeterminant;
n33[6] = (m44[ 1] * m44[ 6] - m44[ 2] * m44[ 5]) * rcpDeterminant;
n33[1] = -(m44[ 4] * m44[10] - m44[ 6] * m44[ 8]) * rcpDeterminant;
n33[4] = (m44[ 0] * m44[10] - m44[ 2] * m44[ 8]) * rcpDeterminant;
n33[7] = -(m44[ 0] * m44[ 6] - m44[ 4] * m44[ 2]) * rcpDeterminant;
n33[2] = (m44[ 4] * m44[ 9] - m44[ 8] * m44[ 5]) * rcpDeterminant;
n33[5] = -(m44[ 0] * m44[ 9] - m44[ 8] * m44[ 1]) * rcpDeterminant;
n33[8] = (m44[ 0] * m44[ 5] - m44[ 4] * m44[ 1]) * rcpDeterminant;
}
static lm_vec3 lm_transformNormal(const float *m, lm_vec3 n)
{
lm_vec3 r;
r.x = m[0] * n.x + m[3] * n.y + m[6] * n.z;
r.y = m[1] * n.x + m[4] * n.y + m[7] * n.z;
r.z = m[2] * n.x + m[5] * n.y + m[8] * n.z;
return r;
}
static lm_vec3 lm_transformPosition(const float *m, lm_vec3 v)
{
if (!m)
return v;
lm_vec3 r;
r.x = m[0] * v.x + m[4] * v.y + m[ 8] * v.z + m[12];
r.y = m[1] * v.x + m[5] * v.y + m[ 9] * v.z + m[13];
r.z = m[2] * v.x + m[6] * v.y + m[10] * v.z + m[14];
float d = m[3] * v.x + m[7] * v.y + m[11] * v.z + m[15];
assert(lm_absf(d - 1.0f) < 0.00001f); // could divide by d, but this shouldn't be a projection transform!
return r;
}
static void lm_setMeshPosition(lm_context *ctx, unsigned int indicesTriangleBaseIndex)
{
// fetch triangle at the specified indicesTriangleBaseIndex
ctx->meshPosition.triangle.baseIndex = indicesTriangleBaseIndex;
// load and transform triangle to process next
lm_vec2 uvMin = lm_v2(FLT_MAX, FLT_MAX), uvMax = lm_v2(-FLT_MAX, -FLT_MAX);
lm_vec2 uvScale = lm_v2i(ctx->lightmap.width, ctx->lightmap.height);
unsigned int vIndices[3];
for (int i = 0; i < 3; i++)
{
// decode index
unsigned int vIndex;
switch (ctx->mesh.indicesType)
{
case LM_NONE:
vIndex = ctx->meshPosition.triangle.baseIndex + i;
break;
case LM_UNSIGNED_BYTE:
vIndex = ((const unsigned char*)ctx->mesh.indices + ctx->meshPosition.triangle.baseIndex)[i];
break;
case LM_UNSIGNED_SHORT:
vIndex = ((const unsigned short*)ctx->mesh.indices + ctx->meshPosition.triangle.baseIndex)[i];
break;
case LM_UNSIGNED_INT:
vIndex = ((const unsigned int*)ctx->mesh.indices + ctx->meshPosition.triangle.baseIndex)[i];
break;
default:
assert(LM_FALSE);
break;
}
vIndices[i] = vIndex;
// decode and pre-transform vertex position
const void *pPtr = ctx->mesh.positions + vIndex * ctx->mesh.positionsStride;
lm_vec3 p;
switch (ctx->mesh.positionsType)
{
// TODO: signed formats
case LM_UNSIGNED_BYTE: {
const unsigned char *uc = (const unsigned char*)pPtr;
p = lm_v3(uc[0], uc[1], uc[2]);
} break;
case LM_UNSIGNED_SHORT: {
const unsigned short *us = (const unsigned short*)pPtr;
p = lm_v3(us[0], us[1], us[2]);
} break;
case LM_UNSIGNED_INT: {
const unsigned int *ui = (const unsigned int*)pPtr;
p = lm_v3((float)ui[0], (float)ui[1], (float)ui[2]);
} break;
case LM_FLOAT: {
p = *(const lm_vec3*)pPtr;
} break;
default: {
assert(LM_FALSE);
} break;
}
ctx->meshPosition.triangle.p[i] = lm_transformPosition(ctx->mesh.modelMatrix, p);
// decode and scale (to lightmap resolution) vertex lightmap texture coords
const void *uvPtr = ctx->mesh.uvs + vIndex * ctx->mesh.uvsStride;
lm_vec2 uv;
switch (ctx->mesh.uvsType)
{
case LM_UNSIGNED_BYTE: {
const unsigned char *uc = (const unsigned char*)uvPtr;
uv = lm_v2(uc[0] / (float)UCHAR_MAX, uc[1] / (float)UCHAR_MAX);
} break;
case LM_UNSIGNED_SHORT: {
const unsigned short *us = (const unsigned short*)uvPtr;
uv = lm_v2(us[0] / (float)USHRT_MAX, us[1] / (float)USHRT_MAX);
} break;
case LM_UNSIGNED_INT: {
const unsigned int *ui = (const unsigned int*)uvPtr;
uv = lm_v2(ui[0] / (float)UINT_MAX, ui[1] / (float)UINT_MAX);
} break;
case LM_FLOAT: {
uv = *(const lm_vec2*)uvPtr;
} break;
default: {
assert(LM_FALSE);
} break;
}
ctx->meshPosition.triangle.uv[i] = lm_mul2(lm_pmod2(uv, 1.0f), uvScale); // maybe clamp to 0.0-1.0 instead of pmod?
// update bounds on lightmap
uvMin = lm_min2(uvMin, ctx->meshPosition.triangle.uv[i]);
uvMax = lm_max2(uvMax, ctx->meshPosition.triangle.uv[i]);
}
lm_vec3 flatNormal = lm_cross3(
lm_sub3(ctx->meshPosition.triangle.p[1], ctx->meshPosition.triangle.p[0]),
lm_sub3(ctx->meshPosition.triangle.p[2], ctx->meshPosition.triangle.p[0]));
for (int i = 0; i < 3; i++)
{
// decode and pre-transform vertex normal
const void *nPtr = ctx->mesh.normals + vIndices[i] * ctx->mesh.normalsStride;
lm_vec3 n;
switch (ctx->mesh.normalsType)
{
// TODO: signed formats
case LM_FLOAT: {
n = *(const lm_vec3*)nPtr;
} break;
case LM_NONE: {
n = flatNormal;
} break;
default: {
assert(LM_FALSE);
} break;
}
ctx->meshPosition.triangle.n[i] = lm_normalize3(lm_transformNormal(ctx->mesh.normalMatrix, n));
}
// calculate area of interest (on lightmap) for conservative rasterization
lm_vec2 bbMin = lm_floor2(uvMin);
lm_vec2 bbMax = lm_ceil2 (uvMax);
ctx->meshPosition.rasterizer.minx = lm_maxi((int)bbMin.x - 1, 0);
ctx->meshPosition.rasterizer.miny = lm_maxi((int)bbMin.y - 1, 0);
ctx->meshPosition.rasterizer.maxx = lm_mini((int)bbMax.x + 1, ctx->lightmap.width - 1);
ctx->meshPosition.rasterizer.maxy = lm_mini((int)bbMax.y + 1, ctx->lightmap.height - 1);
assert(ctx->meshPosition.rasterizer.minx <= ctx->meshPosition.rasterizer.maxx &&
ctx->meshPosition.rasterizer.miny <= ctx->meshPosition.rasterizer.maxy);
ctx->meshPosition.rasterizer.x = ctx->meshPosition.rasterizer.minx + lm_passOffsetX(ctx);
ctx->meshPosition.rasterizer.y = ctx->meshPosition.rasterizer.miny + lm_passOffsetY(ctx);
// try moving to first valid sample position
if (ctx->meshPosition.rasterizer.x <= ctx->meshPosition.rasterizer.maxx &&
ctx->meshPosition.rasterizer.y <= ctx->meshPosition.rasterizer.maxy &&
lm_findFirstConservativeTriangleRasterizerPosition(ctx))
ctx->meshPosition.hemisphere.side = 0; // we can start sampling the hemisphere
else
ctx->meshPosition.hemisphere.side = 5; // no samples on this triangle! put hemisphere sampler into finished state
}
static GLuint lm_LoadShader(GLenum type, const char *source)
{
GLuint shader = glCreateShader(type);
if (shader == 0)
{
fprintf(stderr, "Could not create shader!\n");
return 0;
}
glShaderSource(shader, 1, &source, NULL);
glCompileShader(shader);
GLint compiled;
glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
if (!compiled)
{
fprintf(stderr, "Could not compile shader!\n");
GLint infoLen = 0;
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLen);
if (infoLen)
{
char* infoLog = (char*)malloc(infoLen);
glGetShaderInfoLog(shader, infoLen, NULL, infoLog);
fprintf(stderr, "%s\n", infoLog);
free(infoLog);
}
glDeleteShader(shader);
return 0;
}
return shader;
}
static GLuint lm_LoadProgram(const char *vp, const char *fp)
{
GLuint program = glCreateProgram();
if (program == 0)
{
fprintf(stderr, "Could not create program!\n");
return 0;
}
GLuint vertexShader = lm_LoadShader(GL_VERTEX_SHADER, vp);
GLuint fragmentShader = lm_LoadShader(GL_FRAGMENT_SHADER, fp);
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
glLinkProgram(program);
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
GLint linked;
glGetProgramiv(program, GL_LINK_STATUS, &linked);
if (!linked)
{
fprintf(stderr, "Could not link program!\n");
GLint infoLen = 0;
glGetProgramiv(program, GL_INFO_LOG_LENGTH, &infoLen);
if (infoLen)
{
char* infoLog = (char*)malloc(sizeof(char) * infoLen);
glGetProgramInfoLog(program, infoLen, NULL, infoLog);
fprintf(stderr, "%s\n", infoLog);
free(infoLog);
}
glDeleteProgram(program);
return 0;
}
return program;
}
static float lm_defaultWeights(float cos_theta, void *userdata)
{
return 1.0f;
}
lm_context *lmCreate(int hemisphereSize, float zNear, float zFar,
float clearR, float clearG, float clearB,
int interpolationPasses, float interpolationThreshold,
float cameraToSurfaceDistanceModifier)
{
assert(hemisphereSize == 512 || hemisphereSize == 256 || hemisphereSize == 128 ||
hemisphereSize == 64 || hemisphereSize == 32 || hemisphereSize == 16);
assert(zNear < zFar && zNear > 0.0f);
assert(cameraToSurfaceDistanceModifier >= -1.0f);
assert(interpolationPasses >= 0 && interpolationPasses <= 8);
assert(interpolationThreshold >= 0.0f);
lm_context *ctx = (lm_context*)LM_CALLOC(1, sizeof(lm_context));
ctx->meshPosition.passCount = 1 + 3 * interpolationPasses;
ctx->interpolationThreshold = interpolationThreshold;
ctx->hemisphere.size = hemisphereSize;
ctx->hemisphere.zNear = zNear;
ctx->hemisphere.zFar = zFar;
ctx->hemisphere.cameraToSurfaceDistanceModifier = cameraToSurfaceDistanceModifier;
ctx->hemisphere.clearColor.r = clearR;
ctx->hemisphere.clearColor.g = clearG;
ctx->hemisphere.clearColor.b = clearB;
// calculate hemisphere batch size
ctx->hemisphere.fbHemiCountX = 1536 / (3 * ctx->hemisphere.size);
ctx->hemisphere.fbHemiCountY = 512 / ctx->hemisphere.size;
// hemisphere batch framebuffers
unsigned int w[] = {
ctx->hemisphere.fbHemiCountX * ctx->hemisphere.size * 3,
ctx->hemisphere.fbHemiCountX * ctx->hemisphere.size / 2 };
unsigned int h[] = {
ctx->hemisphere.fbHemiCountY * ctx->hemisphere.size,
ctx->hemisphere.fbHemiCountY * ctx->hemisphere.size / 2 };
glGenTextures(2, ctx->hemisphere.fbTexture);
glGenFramebuffers(2, ctx->hemisphere.fb);
glGenRenderbuffers(1, &ctx->hemisphere.fbDepth);
glBindRenderbuffer(GL_RENDERBUFFER, ctx->hemisphere.fbDepth);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, w[0], h[0]);
glBindFramebuffer(GL_FRAMEBUFFER, ctx->hemisphere.fb[0]);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, ctx->hemisphere.fbDepth);
for (int i = 0; i < 2; i++)
{
glBindTexture(GL_TEXTURE_2D, ctx->hemisphere.fbTexture[i]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, w[i], h[i], 0, GL_RGBA, GL_FLOAT, 0);
glBindFramebuffer(GL_FRAMEBUFFER, ctx->hemisphere.fb[i]);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, ctx->hemisphere.fbTexture[i], 0);
GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if (status != GL_FRAMEBUFFER_COMPLETE)
{
fprintf(stderr, "Could not create framebuffer!\n");
glDeleteRenderbuffers(1, &ctx->hemisphere.fbDepth);
glDeleteFramebuffers(2, ctx->hemisphere.fb);
glDeleteTextures(2, ctx->hemisphere.fbTexture);
LM_FREE(ctx);
return NULL;
}
}
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// dummy vao for fullscreen quad rendering
glGenVertexArrays(1, &ctx->hemisphere.vao);
// hemisphere shader (weighted downsampling of the 3x1 hemisphere layout to a 0.5x0.5 square)
{
const char *vs =
"#version 150 core\n"
"const vec2 ps[4] = vec2[](vec2(1, -1), vec2(1, 1), vec2(-1, -1), vec2(-1, 1));\n"
"void main()\n"
"{\n"
"gl_Position = vec4(ps[gl_VertexID], 0, 1);\n"
"}\n";
const char *fs =
"#version 150 core\n"
"uniform sampler2D hemispheres;\n"
"uniform sampler2D weights;\n"
"layout(pixel_center_integer) in vec4 gl_FragCoord;\n" // whole integer values represent pixel centers, GL_ARB_fragment_coord_conventions
"out vec4 outColor;\n"
"vec4 weightedSample(ivec2 h_uv, ivec2 w_uv, ivec2 quadrant)\n"
"{\n"
"vec4 sample = texelFetch(hemispheres, h_uv + quadrant, 0);\n"
"vec2 weight = texelFetch(weights, w_uv + quadrant, 0).rg;\n"
"return vec4(sample.rgb * weight.r, sample.a * weight.g);\n"
"}\n"
"vec4 threeWeightedSamples(ivec2 h_uv, ivec2 w_uv, ivec2 offset)\n"
"{\n" // horizontal triple sum
"vec4 sum = weightedSample(h_uv, w_uv, offset);\n"
"sum += weightedSample(h_uv, w_uv, offset + ivec2(2, 0));\n"
"sum += weightedSample(h_uv, w_uv, offset + ivec2(4, 0));\n"
"return sum;\n"
"}\n"
"void main()\n"
"{\n" // this is a weighted sum downsampling pass (alpha component contains the weighted valid sample count)
"vec2 in_uv = gl_FragCoord.xy * vec2(6.0, 2.0) + vec2(0.5);\n"
"ivec2 h_uv = ivec2(in_uv);\n"
"ivec2 w_uv = ivec2(mod(in_uv, vec2(textureSize(weights, 0))));\n" // there's no integer modulo :(
"vec4 lb = threeWeightedSamples(h_uv, w_uv, ivec2(0, 0));\n"
"vec4 rb = threeWeightedSamples(h_uv, w_uv, ivec2(1, 0));\n"
"vec4 lt = threeWeightedSamples(h_uv, w_uv, ivec2(0, 1));\n"
"vec4 rt = threeWeightedSamples(h_uv, w_uv, ivec2(1, 1));\n"
"outColor = lb + rb + lt + rt;\n"
"}\n";
ctx->hemisphere.firstPass.programID = lm_LoadProgram(vs, fs);
if (!ctx->hemisphere.firstPass.programID)
{
fprintf(stderr, "Error loading the hemisphere first pass shader program... leaving!\n");
glDeleteVertexArrays(1, &ctx->hemisphere.vao);
glDeleteRenderbuffers(1, &ctx->hemisphere.fbDepth);
glDeleteFramebuffers(2, ctx->hemisphere.fb);
glDeleteTextures(2, ctx->hemisphere.fbTexture);
LM_FREE(ctx);
return NULL;
}
ctx->hemisphere.firstPass.hemispheresTextureID = glGetUniformLocation(ctx->hemisphere.firstPass.programID, "hemispheres");
ctx->hemisphere.firstPass.weightsTextureID = glGetUniformLocation(ctx->hemisphere.firstPass.programID, "weights");
}
// downsample shader
{
const char *vs =
"#version 150 core\n"
"const vec2 ps[4] = vec2[](vec2(1, -1), vec2(1, 1), vec2(-1, -1), vec2(-1, 1));\n"
"void main()\n"
"{\n"
"gl_Position = vec4(ps[gl_VertexID], 0, 1);\n"
"}\n";
const char *fs =
"#version 150 core\n"
"uniform sampler2D hemispheres;\n"
"layout(pixel_center_integer) in vec4 gl_FragCoord;\n" // whole integer values represent pixel centers, GL_ARB_fragment_coord_conventions
"out vec4 outColor;\n"
"void main()\n"
"{\n" // this is a sum downsampling pass (alpha component contains the weighted valid sample count)
"ivec2 h_uv = ivec2(gl_FragCoord.xy) * 2;\n"
"vec4 lb = texelFetch(hemispheres, h_uv + ivec2(0, 0), 0);\n"
"vec4 rb = texelFetch(hemispheres, h_uv + ivec2(1, 0), 0);\n"
"vec4 lt = texelFetch(hemispheres, h_uv + ivec2(0, 1), 0);\n"
"vec4 rt = texelFetch(hemispheres, h_uv + ivec2(1, 1), 0);\n"
"outColor = lb + rb + lt + rt;\n"
"}\n";
ctx->hemisphere.downsamplePass.programID = lm_LoadProgram(vs, fs);
if (!ctx->hemisphere.downsamplePass.programID)
{
fprintf(stderr, "Error loading the hemisphere downsample pass shader program... leaving!\n");
glDeleteProgram(ctx->hemisphere.firstPass.programID);
glDeleteVertexArrays(1, &ctx->hemisphere.vao);
glDeleteRenderbuffers(1, &ctx->hemisphere.fbDepth);
glDeleteFramebuffers(2, ctx->hemisphere.fb);
glDeleteTextures(2, ctx->hemisphere.fbTexture);
LM_FREE(ctx);
return NULL;
}
ctx->hemisphere.downsamplePass.hemispheresTextureID = glGetUniformLocation(ctx->hemisphere.downsamplePass.programID, "hemispheres");
}
// hemisphere weights texture
glGenTextures(1, &ctx->hemisphere.firstPass.weightsTexture);
lmSetHemisphereWeights(ctx, lm_defaultWeights, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// allocate batchPosition-to-lightmapPosition map
ctx->hemisphere.fbHemiToLightmapLocation = (lm_ivec2*)LM_CALLOC(ctx->hemisphere.fbHemiCountX * ctx->hemisphere.fbHemiCountY, sizeof(lm_ivec2));
return ctx;
}
void lmDestroy(lm_context *ctx)
{
// reset state
glUseProgram(0);
glBindTexture(GL_TEXTURE_2D, 0);
glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
glBindVertexArray(0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
// delete gl objects
glDeleteTextures(1, &ctx->hemisphere.firstPass.weightsTexture);
glDeleteTextures(1, &ctx->hemisphere.storage.texture);
glDeleteProgram(ctx->hemisphere.downsamplePass.programID);
glDeleteProgram(ctx->hemisphere.firstPass.programID);
glDeleteVertexArrays(1, &ctx->hemisphere.vao);
glDeleteRenderbuffers(1, &ctx->hemisphere.fbDepth);
glDeleteFramebuffers(2, ctx->hemisphere.fb);
glDeleteTextures(2, ctx->hemisphere.fbTexture);
glDeleteTextures(1, &ctx->hemisphere.storage.texture);
// free memory
LM_FREE(ctx->hemisphere.storage.toLightmapLocation);
LM_FREE(ctx->hemisphere.fbHemiToLightmapLocation);
#ifdef LM_DEBUG_INTERPOLATION
LM_FREE(ctx->lightmap.debug);
#endif
LM_FREE(ctx);
}
void lmSetHemisphereWeights(lm_context *ctx, lm_weight_func f, void *userdata)
{
// hemisphere weights texture. bakes in material dependent attenuation behaviour.
float *weights = (float*)LM_CALLOC(2 * 3 * ctx->hemisphere.size * ctx->hemisphere.size, sizeof(float));
float center = (ctx->hemisphere.size - 1) * 0.5f;
double sum = 0.0;
for (unsigned int y = 0; y < ctx->hemisphere.size; y++)
{
float dy = 2.0f * (y - center) / (float)ctx->hemisphere.size;
for (unsigned int x = 0; x < ctx->hemisphere.size; x++)
{
float dx = 2.0f * (x - center) / (float)ctx->hemisphere.size;
lm_vec3 v = lm_normalize3(lm_v3(dx, dy, 1.0f));
float solidAngle = v.z * v.z * v.z;
float *w0 = weights + 2 * (y * (3 * ctx->hemisphere.size) + x);
float *w1 = w0 + 2 * ctx->hemisphere.size;
float *w2 = w1 + 2 * ctx->hemisphere.size;
// center weights
w0[0] = solidAngle * f(v.z, userdata);
w0[1] = solidAngle;
// left/right side weights
w1[0] = solidAngle * f(lm_absf(v.x), userdata);
w1[1] = solidAngle;
// up/down side weights
w2[0] = solidAngle * f(lm_absf(v.y), userdata);
w2[1] = solidAngle;
sum += 3.0 * (double)solidAngle;
}
}
// normalize weights
float weightScale = (float)(1.0 / sum);
for (unsigned int i = 0; i < 2 * 3 * ctx->hemisphere.size * ctx->hemisphere.size; i++)
weights[i] *= weightScale;
// upload weight texture
glBindTexture(GL_TEXTURE_2D, ctx->hemisphere.firstPass.weightsTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RG32F, 3 * ctx->hemisphere.size, ctx->hemisphere.size, 0, GL_RG, GL_FLOAT, weights);
LM_FREE(weights);
}
void lmSetTargetLightmap(lm_context *ctx, float *outLightmap, int w, int h, int c)
{
ctx->lightmap.data = outLightmap;
ctx->lightmap.width = w;
ctx->lightmap.height = h;
ctx->lightmap.channels = c;
// allocate storage texture
if (!ctx->hemisphere.storage.texture)
glGenTextures(1, &ctx->hemisphere.storage.texture);
glBindTexture(GL_TEXTURE_2D, ctx->hemisphere.storage.texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, w, h, 0, GL_RGBA, GL_FLOAT, 0);
// allocate storage position to lightmap position map
if (ctx->hemisphere.storage.toLightmapLocation)
LM_FREE(ctx->hemisphere.storage.toLightmapLocation);
ctx->hemisphere.storage.toLightmapLocation = (lm_ivec2*)LM_CALLOC(w * h, sizeof(lm_ivec2));
// invalidate all positions
for (int i = 0; i < w * h; i++)
ctx->hemisphere.storage.toLightmapLocation[i].x = -1;
#ifdef LM_DEBUG_INTERPOLATION
if (ctx->lightmap.debug)
LM_FREE(ctx->lightmap.debug);
ctx->lightmap.debug = (unsigned char*)LM_CALLOC(ctx->lightmap.width * ctx->lightmap.height, 3);
#endif
}
void lmSetGeometry(lm_context *ctx,
const float *transformationMatrix,
lm_type positionsType, const void *positionsXYZ, int positionsStride,
lm_type normalsType, const void *normalsXYZ, int normalsStride,
lm_type lightmapCoordsType, const void *lightmapCoordsUV, int lightmapCoordsStride,
int count, lm_type indicesType, const void *indices)
{
ctx->mesh.modelMatrix = transformationMatrix;
ctx->mesh.positions = (const unsigned char*)positionsXYZ;
ctx->mesh.positionsType = positionsType;
ctx->mesh.positionsStride = positionsStride == 0 ? sizeof(lm_vec3) : positionsStride;
ctx->mesh.normals = (const unsigned char*)normalsXYZ;
ctx->mesh.normalsType = normalsType;
ctx->mesh.normalsStride = normalsStride == 0 ? sizeof(lm_vec3) : normalsStride;
ctx->mesh.uvs = (const unsigned char*)lightmapCoordsUV;
ctx->mesh.uvsType = lightmapCoordsType;
ctx->mesh.uvsStride = lightmapCoordsStride == 0 ? sizeof(lm_vec2) : lightmapCoordsStride;
ctx->mesh.indicesType = indicesType;
ctx->mesh.indices = (const unsigned char*)indices;
ctx->mesh.count = count;
lm_inverseTranspose(transformationMatrix, ctx->mesh.normalMatrix);
ctx->meshPosition.pass = 0;
lm_setMeshPosition(ctx, 0);
}
lm_bool lmBegin(lm_context *ctx, int* outViewport4, float* outView4x4, float* outProjection4x4)
{
assert(ctx->meshPosition.triangle.baseIndex < ctx->mesh.count);
while (!lm_beginSampleHemisphere(ctx, outViewport4, outView4x4, outProjection4x4))
{ // as long as there are no hemisphere sides to render...
// try moving to the next rasterizer position
if (lm_findNextConservativeTriangleRasterizerPosition(ctx))
{ // if we successfully moved to the next sample position on the current triangle...
ctx->meshPosition.hemisphere.side = 0; // start sampling a hemisphere there
}
else
{ // if there are no valid sample positions on the current triangle...
if (ctx->meshPosition.triangle.baseIndex + 3 < ctx->mesh.count)
{ // ...and there are triangles left: move to the next triangle and continue sampling.
lm_setMeshPosition(ctx, ctx->meshPosition.triangle.baseIndex + 3);
}
else
{ // ...and there are no triangles left: finish
lm_integrateHemisphereBatch(ctx); // integrate and store last batch
lm_writeResultsToLightmap(ctx); // read storage data from gpu memory and write it to the lightmap
if (++ctx->meshPosition.pass == ctx->meshPosition.passCount)
{
ctx->meshPosition.pass = 0;
ctx->meshPosition.triangle.baseIndex = ctx->mesh.count; // set end condition (in case someone accidentally calls lmBegin again)
#ifdef LM_DEBUG_INTERPOLATION
lmImageSaveTGAub("debug_interpolation.tga", ctx->lightmap.debug, ctx->lightmap.width, ctx->lightmap.height, 3);
// lightmap texel statistics
int rendered = 0, interpolated = 0, wasted = 0;
for (int y = 0; y < ctx->lightmap.height; y++)
{
for (int x = 0; x < ctx->lightmap.width; x++)
{
if (ctx->lightmap.debug[(y * ctx->lightmap.width + x) * 3 + 0])
rendered++;
else if (ctx->lightmap.debug[(y * ctx->lightmap.width + x) * 3 + 1])
interpolated++;
else
wasted++;
}
}
int used = rendered + interpolated;
int total = used + wasted;
printf("\n#######################################################################\n");
printf("%10d %6.2f%% rendered hemicubes integrated to lightmap texels.\n", rendered, 100.0f * (float)rendered / (float)total);
printf("%10d %6.2f%% interpolated lightmap texels.\n", interpolated, 100.0f * (float)interpolated / (float)total);
printf("%10d %6.2f%% wasted lightmap texels.\n", wasted, 100.0f * (float)wasted / (float)total);
printf("\n%17.2f%% of used texels were rendered.\n", 100.0f * (float)rendered / (float)used);
printf("#######################################################################\n");
#endif
return LM_FALSE;
}
lm_setMeshPosition(ctx, 0); // start over with the next pass
}
}
}
return LM_TRUE;
}
float lmProgress(lm_context *ctx)
{
float passProgress = (float)ctx->meshPosition.triangle.baseIndex / (float)ctx->mesh.count;
return ((float)ctx->meshPosition.pass + passProgress) / (float)ctx->meshPosition.passCount;
}
void lmEnd(lm_context *ctx)
{
lm_endSampleHemisphere(ctx);
}
// these are not performance tuned since their impact on the whole lightmapping duration is insignificant
float lmImageMin(const float *image, int w, int h, int c, int m)
{
assert(c > 0 && m);
float minValue = FLT_MAX;
for (int i = 0; i < w * h; i++)
for (int j = 0; j < c; j++)
if (m & (1 << j))
minValue = lm_minf(minValue, image[i * c + j]);
return minValue;
}
float lmImageMax(const float *image, int w, int h, int c, int m)
{
assert(c > 0 && m);
float maxValue = 0.0f;
for (int i = 0; i < w * h; i++)
for (int j = 0; j < c; j++)
if (m & (1 << j))
maxValue = lm_maxf(maxValue, image[i * c + j]);
return maxValue;
}
void lmImageAdd(float *image, int w, int h, int c, float value, int m)
{
assert(c > 0 && m);
for (int i = 0; i < w * h; i++)
for (int j = 0; j < c; j++)
if (m & (1 << j))
image[i * c + j] += value;
}
void lmImageScale(float *image, int w, int h, int c, float factor, int m)
{
assert(c > 0 && m);
for (int i = 0; i < w * h; i++)
for (int j = 0; j < c; j++)
if (m & (1 << j))
image[i * c + j] *= factor;
}
void lmImagePower(float *image, int w, int h, int c, float exponent, int m)
{
assert(c > 0 && m);
for (int i = 0; i < w * h; i++)
for (int j = 0; j < c; j++)
if (m & (1 << j))
image[i * c + j] = powf(image[i * c + j], exponent);
}
void lmImageDilate(const float *image, float *outImage, int w, int h, int c)
{
assert(c > 0 && c <= 4);
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
float color[4];
lm_bool valid = LM_FALSE;
for (int i = 0; i < c; i++)
{
color[i] = image[(y * w + x) * c + i];
valid |= color[i] > 0.0f;
}
if (!valid)
{
int n = 0;
const int dx[] = { -1, 0, 1, 0 };
const int dy[] = { 0, 1, 0, -1 };
for (int d = 0; d < 4; d++)
{
int cx = x + dx[d];
int cy = y + dy[d];
if (cx >= 0 && cx < w && cy >= 0 && cy < h)
{
float dcolor[4];
lm_bool dvalid = LM_FALSE;
for (int i = 0; i < c; i++)
{
dcolor[i] = image[(cy * w + cx) * c + i];
dvalid |= dcolor[i] > 0.0f;
}
if (dvalid)
{
for (int i = 0; i < c; i++)
color[i] += dcolor[i];
n++;
}
}
}
if (n)
{
float in = 1.0f / n;
for (int i = 0; i < c; i++)
color[i] *= in;
}
}
for (int i = 0; i < c; i++)
outImage[(y * w + x) * c + i] = color[i];
}
}
}
void lmImageSmooth(const float *image, float *outImage, int w, int h, int c)
{
assert(c > 0 && c <= 4);
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
float color[4] = {0};
int n = 0;
for (int dy = -1; dy <= 1; dy++)
{
int cy = y + dy;
for (int dx = -1; dx <= 1; dx++)
{
int cx = x + dx;
if (cx >= 0 && cx < w && cy >= 0 && cy < h)
{
lm_bool valid = LM_FALSE;
for (int i = 0; i < c; i++)
valid |= image[(cy * w + cx) * c + i] > 0.0f;
if (valid)
{
for (int i = 0; i < c; i++)
color[i] += image[(cy * w + cx) * c + i];
n++;
}
}
}
}
for (int i = 0; i < c; i++)
outImage[(y * w + x) * c + i] = n ? color[i] / n : 0.0f;
}
}
}
void lmImageDownsample(const float *image, float *outImage, int w, int h, int c)
{
assert(c > 0 && c <= 4);
for (int y = 0; y < h / 2; y++)
{
for (int x = 0; x < w / 2; x++)
{
int p0 = 2 * (y * w + x) * c;
int p1 = p0 + w * c;
int valid[2][2] = {0};
float sums[4] = {0};
for (int i = 0; i < c; i++)
{
valid[0][0] |= image[p0 + i] != 0.0f ? 1 : 0;
valid[0][1] |= image[p0 + c + i] != 0.0f ? 1 : 0;
valid[1][0] |= image[p1 + i] != 0.0f ? 1 : 0;
valid[1][1] |= image[p1 + c + i] != 0.0f ? 1 : 0;
sums[i] += image[p0 + i] + image[p0 + c + i] + image[p1 + i] + image[p1 + c + i];
}
int n = valid[0][0] + valid[0][1] + valid[1][0] + valid[1][1];
int p = (y * w / 2 + x) * c;
for (int i = 0; i < c; i++)
outImage[p + i] = n ? sums[i] / n : 0.0f;
}
}
}
void lmImageFtoUB(const float *image, unsigned char *outImage, int w, int h, int c, float max)
{
assert(c > 0);
float scale = 255.0f / (max != 0.0f ? max : lmImageMax(image, w, h, c, LM_ALL_CHANNELS));
for (int i = 0; i < w * h * c; i++)
outImage[i] = (unsigned char)lm_minf(lm_maxf(image[i] * scale, 0.0f), 255.0f);
}
// TGA output helpers
static void lm_swapRandBub(unsigned char *image, int w, int h, int c)
{
assert(c >= 3);
for (int i = 0; i < w * h * c; i += c)
LM_SWAP(unsigned char, image[i], image[i + 2]);
}
lm_bool lmImageSaveTGAub(const char *filename, const unsigned char *image, int w, int h, int c)
{
assert(c == 1 || c == 3 || c == 4);
lm_bool isGreyscale = c == 1;
lm_bool hasAlpha = c == 4;
unsigned char header[18] = {
0, 0, (unsigned char)(isGreyscale ? 3 : 2), 0, 0, 0, 0, 0, 0, 0, 0, 0,
(unsigned char)(w & 0xff), (unsigned char)((w >> 8) & 0xff), (unsigned char)(h & 0xff), (unsigned char)((h >> 8) & 0xff),
(unsigned char)(8 * c), (unsigned char)(hasAlpha ? 8 : 0)
};
#if defined(_MSC_VER) && _MSC_VER >= 1400
FILE *file;
if (fopen_s(&file, filename, "wb") != 0) return LM_FALSE;
#else
FILE *file = fopen(filename, "wb");
if (!file) return LM_FALSE;
#endif
fwrite(header, 1, sizeof(header), file);
// we make sure to swap it back! trust me. :)
if (!isGreyscale)
lm_swapRandBub((unsigned char*)image, w, h, c);
fwrite(image, 1, w * h * c , file);
if (!isGreyscale)
lm_swapRandBub((unsigned char*)image, w, h, c);
fclose(file);
return LM_TRUE;
}
lm_bool lmImageSaveTGAf(const char *filename, const float *image, int w, int h, int c, float max)
{
unsigned char *temp = (unsigned char*)LM_CALLOC(w * h * c, sizeof(unsigned char));
lmImageFtoUB(image, temp, w, h, c, max);
lm_bool success = lmImageSaveTGAub(filename, temp, w, h, c);
LM_FREE(temp);
return success;
}
#endif // LIGHTMAPPER_IMPLEMENTATION
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