assimp/samples/SimpleOpenGL/Sample_SimpleOpenGL.c

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// ----------------------------------------------------------------------------
// Simple sample to prove that Assimp is easy to use with OpenGL.
// It takes a file name as command line parameter, loads it using standard
// settings and displays it.
//
// If you intend to _use_ this code sample in your app, do yourself a favour
// and replace immediate mode calls with VBOs ...
//
// The vc8 solution links against assimp-release-dll_win32 - be sure to
// have this configuration built.
// ----------------------------------------------------------------------------
#include "GL/glut.h"
// assimp include files. These three are usually needed.
#include "assimp.h"
#include "aiPostProcess.h"
#include "aiScene.h"
// the global Assimp scene object
const struct aiScene* scene = NULL;
GLuint scene_list = 0;
struct aiVector3D scene_min, scene_max, scene_center;
// current rotation angle
static float angle = 0.f;
#define aisgl_min(x,y) (x<y?x:y)
#define aisgl_max(x,y) (y>x?y:x)
// ----------------------------------------------------------------------------
void reshape(int width, int height)
{
const double aspectRatio = (float) width / height, fieldOfView = 45.0;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(fieldOfView, aspectRatio,
1.0, 1000.0); /* Znear and Zfar */
glViewport(0, 0, width, height);
}
// ----------------------------------------------------------------------------
void get_bounding_box_for_node (const struct aiNode* nd,
struct aiVector3D* min,
struct aiVector3D* max,
struct aiMatrix4x4* trafo
){
struct aiMatrix4x4 prev;
unsigned int n = 0, t;
prev = *trafo;
aiMultiplyMatrix4(trafo,&nd->mTransformation);
for (; n < nd->mNumMeshes; ++n) {
const struct aiMesh* mesh = scene->mMeshes[nd->mMeshes[n]];
for (t = 0; t < mesh->mNumVertices; ++t) {
struct aiVector3D tmp = mesh->mVertices[t];
aiTransformVecByMatrix4(&tmp,trafo);
min->x = aisgl_min(min->x,tmp.x);
min->y = aisgl_min(min->y,tmp.y);
min->z = aisgl_min(min->z,tmp.z);
max->x = aisgl_max(max->x,tmp.x);
max->y = aisgl_max(max->y,tmp.y);
max->z = aisgl_max(max->z,tmp.z);
}
}
for (n = 0; n < nd->mNumChildren; ++n) {
get_bounding_box_for_node(nd->mChildren[n],min,max,trafo);
}
*trafo = prev;
}
// ----------------------------------------------------------------------------
void get_bounding_box (struct aiVector3D* min, struct aiVector3D* max)
{
struct aiMatrix4x4 trafo;
aiIdentityMatrix4(&trafo);
min->x = min->y = min->z = 1e10f;
max->x = max->y = max->z = -1e10f;
get_bounding_box_for_node(scene->mRootNode,min,max,&trafo);
}
// ----------------------------------------------------------------------------
void color4_to_float4(const struct aiColor4D *c, float f[4])
{
f[0] = c->r;
f[1] = c->g;
f[2] = c->b;
f[3] = c->a;
}
void set_float4(float f[4], float a, float b, float c, float d)
{
f[0] = a;
f[1] = b;
f[2] = c;
f[3] = d;
}
// ----------------------------------------------------------------------------
void apply_material(const struct aiMaterial *mtl)
{
float c[4];
GLenum fill_mode;
int ret1, ret2;
struct aiColor4D diffuse;
struct aiColor4D specular;
struct aiColor4D ambient;
struct aiColor4D emission;
float shininess, strength;
int two_sided;
int wireframe;
int max;
set_float4(c, 0.8f, 0.8f, 0.8f, 1.0f);
if(AI_SUCCESS == aiGetMaterialColor(mtl, AI_MATKEY_COLOR_DIFFUSE, &diffuse))
color4_to_float4(&diffuse, c);
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, c);
set_float4(c, 0.0f, 0.0f, 0.0f, 1.0f);
if(AI_SUCCESS == aiGetMaterialColor(mtl, AI_MATKEY_COLOR_SPECULAR, &specular))
color4_to_float4(&specular, c);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, c);
set_float4(c, 0.2f, 0.2f, 0.2f, 1.0f);
if(AI_SUCCESS == aiGetMaterialColor(mtl, AI_MATKEY_COLOR_AMBIENT, &ambient))
color4_to_float4(&ambient, c);
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, c);
set_float4(c, 0.0f, 0.0f, 0.0f, 1.0f);
if(AI_SUCCESS == aiGetMaterialColor(mtl, AI_MATKEY_COLOR_EMISSIVE, &emission))
color4_to_float4(&emission, c);
glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, c);
max = 1;
ret1 = aiGetMaterialFloatArray(mtl, AI_MATKEY_SHININESS, &shininess, &max);
max = 1;
ret2 = aiGetMaterialFloatArray(mtl, AI_MATKEY_SHININESS_STRENGTH, &strength, &max);
if((ret1 == AI_SUCCESS) && (ret2 == AI_SUCCESS))
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, shininess * strength);
else {
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 0.0f);
set_float4(c, 0.0f, 0.0f, 0.0f, 0.0f);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, c);
}
max = 1;
if(AI_SUCCESS == aiGetMaterialIntegerArray(mtl, AI_MATKEY_ENABLE_WIREFRAME, &wireframe, &max))
fill_mode = wireframe ? GL_LINE : GL_FILL;
else
fill_mode = GL_FILL;
glPolygonMode(GL_FRONT_AND_BACK, fill_mode);
max = 1;
if((AI_SUCCESS == aiGetMaterialIntegerArray(mtl, AI_MATKEY_TWOSIDED, &two_sided, &max)) && two_sided)
glEnable(GL_CULL_FACE);
else
glDisable(GL_CULL_FACE);
}
// ----------------------------------------------------------------------------
// Can't send color down as a pointer to aiColor4D because AI colors are ABGR.
void Color4f(const struct aiColor4D *color)
{
glColor4f(color->r, color->g, color->b, color->a);
}
// ----------------------------------------------------------------------------
void recursive_render (const struct aiScene *sc, const struct aiNode* nd)
{
int i;
unsigned int n = 0, t;
struct aiMatrix4x4 m = nd->mTransformation;
// update transform
aiTransposeMatrix4(&m);
glPushMatrix();
glMultMatrixf((float*)&m);
// draw all meshes assigned to this node
for (; n < nd->mNumMeshes; ++n) {
const struct aiMesh* mesh = scene->mMeshes[nd->mMeshes[n]];
apply_material(sc->mMaterials[mesh->mMaterialIndex]);
if(mesh->mNormals == NULL) {
glDisable(GL_LIGHTING);
} else {
glEnable(GL_LIGHTING);
}
if(mesh->mColors[0] != NULL) {
glEnable(GL_COLOR_MATERIAL);
} else {
glDisable(GL_COLOR_MATERIAL);
}
for (t = 0; t < mesh->mNumFaces; ++t) {
const struct aiFace* face = &mesh->mFaces[t];
GLenum face_mode;
switch(face->mNumIndices) {
case 1: face_mode = GL_POINTS; break;
case 2: face_mode = GL_LINES; break;
case 3: face_mode = GL_TRIANGLES; break;
default: face_mode = GL_POLYGON; break;
}
glBegin(face_mode);
for(i = 0; i < face->mNumIndices; i++) {
int index = face->mIndices[i];
if(mesh->mColors[0] != NULL)
Color4f(&mesh->mColors[0][index]);
if(mesh->mNormals != NULL)
glNormal3fv(&mesh->mNormals[index].x);
glVertex3fv(&mesh->mVertices[index].x);
}
glEnd();
}
}
// draw all children
for (n = 0; n < nd->mNumChildren; ++n) {
recursive_render(sc, nd->mChildren[n]);
}
glPopMatrix();
}
// ----------------------------------------------------------------------------
void do_motion (void)
{
static GLint prev_time = 0;
int time = glutGet(GLUT_ELAPSED_TIME);
angle += (time-prev_time)*0.01;
prev_time = time;
glutPostRedisplay ();
}
// ----------------------------------------------------------------------------
void display(void)
{
float tmp;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0.f,0.f,3.f,0.f,0.f,-5.f,0.f,1.f,0.f);
// rotate it around the y axis
glRotatef(angle,0.f,1.f,0.f);
// scale the whole asset to fit into our view frustum
tmp = scene_max.x-scene_min.x;
tmp = aisgl_max(scene_max.y - scene_min.y,tmp);
tmp = aisgl_max(scene_max.z - scene_min.z,tmp);
tmp = 1.f / tmp;
glScalef(tmp, tmp, tmp);
// center the model
glTranslatef( -scene_center.x, -scene_center.y, -scene_center.z );
// if the display list has not been made yet, create a new one and
// fill it with scene contents
if(scene_list == 0) {
scene_list = glGenLists(1);
glNewList(scene_list, GL_COMPILE);
// now begin at the root node of the imported data and traverse
// the scenegraph by multiplying subsequent local transforms
// together on GL's matrix stack.
recursive_render(scene, scene->mRootNode);
glEndList();
}
glCallList(scene_list);
glutSwapBuffers();
do_motion();
}
// ----------------------------------------------------------------------------
int loadasset (const char* path)
{
// we are taking one of the postprocessing presets to avoid
// writing 20 single postprocessing flags here.
scene = aiImportFile(path,aiProcessPreset_TargetRealtime_Quality);
if (scene) {
get_bounding_box(&scene_min,&scene_max);
scene_center.x = (scene_min.x + scene_max.x) / 2.0f;
scene_center.y = (scene_min.y + scene_max.y) / 2.0f;
scene_center.z = (scene_min.z + scene_max.z) / 2.0f;
return 0;
}
return 1;
}
// ----------------------------------------------------------------------------
int main(int argc, char **argv)
{
struct aiLogStream stream;
glutInitWindowSize(900,600);
glutInitWindowPosition(100,100);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
glutInit(&argc, argv);
glutCreateWindow("Assimp - Very simple OpenGL sample");
glutDisplayFunc(display);
glutReshapeFunc(reshape);
// get a handle to the predefined STDOUT log stream and attach
// it to the logging system. It will be active for all further
// calls to aiImportFile(Ex) and aiApplyPostProcessing.
stream = aiGetPredefinedLogStream(aiDefaultLogStream_STDOUT,NULL);
aiAttachLogStream(&stream);
// ... exactly the same, but this stream will now write the
// log file to assimp_log.txt
stream = aiGetPredefinedLogStream(aiDefaultLogStream_FILE,"assimp_log.txt");
aiAttachLogStream(&stream);
if( 0 != loadasset( argc >= 2 ? argv[1] : "../../test/models/X/dwarf.x")) {
if( argc != 1 || 0 != loadasset( "../../../../test/models/X/dwarf.x")) {
return -1;
}
}
glClearColor(0.1f,0.1f,0.1f,1.f);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0); // Uses default lighting parameters
glEnable(GL_DEPTH_TEST);
glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
glEnable(GL_NORMALIZE);
// XXX docs say all polygons are emitted CCW, but tests show that some aren't.
if(getenv("MODEL_IS_BROKEN"))
glFrontFace(GL_CW);
glColorMaterial(GL_FRONT_AND_BACK, GL_DIFFUSE);
glutGet(GLUT_ELAPSED_TIME);
glutMainLoop();
// cleanup - calling 'aiReleaseImport' is important, as the library
// keeps internal resources until the scene is freed again. Not
// doing so can cause severe resource leaking.
aiReleaseImport(scene);
// We added a log stream to the library, it's our job to disable it
// again. This will definitely release the last resources allocated
// by Assimp.
aiDetachAllLogStreams();
return 0;
}