From bc5727eb20786474f32fa1c0644c74ec7ced4a7f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dominik=20Madar=C3=A1sz?= <zaklaus@outlook.com>
Date: Sat, 9 Sep 2023 02:36:52 +0200
Subject: [PATCH] demo: temperature sim

---
 demos/99-temperature.c             | 95 ++++++++++++++++++++++++++++++
 demos/art/shaders/temperature.glsl | 20 +++++++
 2 files changed, 115 insertions(+)
 create mode 100644 demos/99-temperature.c
 create mode 100644 demos/art/shaders/temperature.glsl

diff --git a/demos/99-temperature.c b/demos/99-temperature.c
new file mode 100644
index 0000000..5eb5dab
--- /dev/null
+++ b/demos/99-temperature.c
@@ -0,0 +1,95 @@
+#include "v4k.h"
+
+#define TEMP_GPU
+
+#ifdef TEMP_GPU
+#define TEX_WIDTH 256
+// #define TEX_WIDTH 64
+#else
+#define TEX_WIDTH 64
+
+void temp_calc(vec4 *pixels){
+    // flood it
+    for (int y = 1; y < TEX_WIDTH-1; y++){
+        for (int x = 1; x < TEX_WIDTH-1; x++){
+            int idx = (y * TEX_WIDTH) + x;
+            vec4 *m = &pixels[idx];
+
+            vec4 sum = vec4(0,0,0,0);
+            for (int cy = -1; cy <= 1; ++cy) {
+                for (int cx = -1; cx <= 1; ++cx) {
+                    sum = add4(sum, pixels[((y+cy)*TEX_WIDTH)+(x+cx)]);
+                }
+            }
+
+            *m = scale4(sum,1/9.0f);
+        }
+    }
+}
+
+#endif
+
+int main() {
+    // 75% sized, MSAAx2
+    window_create(50, WINDOW_SQUARE);
+    window_title(__FILE__);
+    // window_fps_lock(1);
+
+    texture_t tex;
+
+    vec4 *img = REALLOC(0, TEX_WIDTH*TEX_WIDTH*sizeof(vec4));
+    for (int i=0; i <TEX_WIDTH*TEX_WIDTH; i++){
+        img[i] = vec4(0.3,0.3,0.3,1);
+    }
+#ifdef TEMP_GPU
+    tex = texture_create(TEX_WIDTH, TEX_WIDTH, 4, img, TEXTURE_LINEAR|TEXTURE_FLOAT);
+    unsigned comp = compute(vfs_read("shaders/temperature.glsl"));
+    shader_bind(comp);
+    shader_image(tex, 0, 0, 0, READ_WRITE);
+#else
+    tex = texture_create(TEX_WIDTH, TEX_WIDTH, 4, img, TEXTURE_LINEAR|TEXTURE_FLOAT);
+#endif
+
+    while ( window_swap() && !input_down(KEY_ESC) ){
+        if (input(KEY_F5)) window_reload();
+
+#ifdef TEMP_GPU
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, tex.id);
+        glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_FLOAT, img);
+#endif
+        for (int i=0; i <TEX_WIDTH*4; i++){
+            img[i] = vec4(0,0,1,1);
+            img[(TEX_WIDTH - 4) * TEX_WIDTH+i] = vec4(1,0,0,1);
+        }
+
+        int enabled = !ui_active() && !ui_hover();
+        vec4 mouse = enabled ? vec4(input(MOUSE_X),input(MOUSE_Y),input(MOUSE_L),input(MOUSE_R)) : vec4(0,0,0,0); // x,y,l,r
+        int strong = input(KEY_LSHIFT)?15:1;
+        int x = (int)clampf(floorf(TEX_WIDTH/(float)window_width() * mouse.x), 0, TEX_WIDTH-1);
+        int y = (int)clampf(floorf(TEX_WIDTH/(float)window_height() * mouse.y), 0, TEX_WIDTH-1);
+
+        if (mouse.z){
+            img[(y*TEX_WIDTH)+x] = vec4(strong*1,0,0,1);
+        }
+
+        if (mouse.w){
+            img[(y*TEX_WIDTH)+x] = vec4(0,0,strong*1,1);
+        }
+
+#ifdef TEMP_GPU        
+        glBindTexture(GL_TEXTURE_2D, tex.id);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, TEX_WIDTH, TEX_WIDTH, 0, GL_RGBA, GL_FLOAT, img);
+        shader_bind(comp);
+        compute_dispatch(TEX_WIDTH/16, TEX_WIDTH/16, 1);
+        image_write_barrier();
+#else
+        temp_calc(img);
+        texture_update(&tex, TEX_WIDTH, TEX_WIDTH, 4, img, TEXTURE_LINEAR|TEXTURE_FLOAT);
+#endif
+
+        fullscreen_quad_rgb(tex, 2.2);
+    }
+
+    return 0;
+}
diff --git a/demos/art/shaders/temperature.glsl b/demos/art/shaders/temperature.glsl
new file mode 100644
index 0000000..df58bf9
--- /dev/null
+++ b/demos/art/shaders/temperature.glsl
@@ -0,0 +1,20 @@
+layout (local_size_x = 16, local_size_y = 16) in;
+
+layout (rgba32f, binding = 0) uniform image2D img;
+
+void main() {
+    ivec2 gid = ivec2(gl_GlobalInvocationID.xy);
+    gid.x = clamp(gid.x, 1, int(gl_NumWorkGroups.x*gl_WorkGroupSize.x)-2);
+    gid.y = clamp(gid.y, 1, int(gl_NumWorkGroups.y*gl_WorkGroupSize.y)-2);
+    vec4 sum = vec4(0);
+
+    for (int y = -1; y <= 1; ++y) {
+        for (int x = -1; x <= 1; ++x) {
+            sum += imageLoad(img, gid + ivec2(x,y));
+        }
+    }
+    vec4 avg = sum / 9.0;
+
+    barrier();
+    imageStore(img, gid, avg);
+}
\ No newline at end of file