opengl_x11

commit cf43653b6fb397f55bff8958d8590afeaf688ad7
parent b4fa258cf6d247b3ec3fdee16250ee1b4cb65d4d
Author: bsandro <email@bsandro.tech>
Date:   Fri, 21 Nov 2025 01:19:41 +0200

cubes rotate with random speed

Diffstat:
M
cube.c
 | 
21
+++++++++++++++++----

1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/cube.c b/cube.c
@@ -16,6 +16,9 @@
 #define STB_IMAGE_IMPLEMENTATION
 #include "stb_image.h"
 
+#define RANDOM(x) (rand() % (x))
+#define LEN(x) (sizeof(x)/sizeof(x[0]))
+
 #define GL_CHECK(x)                                                                           \
 x;                                                                                            \
 {                                                                                             \
@@ -105,6 +108,8 @@ void __attribute__((constructor)) start() {
     glm_mat4_print(trans1, stdout);
 
     t_started = current_ts();
+
+    srand(time(0));
 }
 
 void __attribute((destructor)) end() {
@@ -267,6 +272,12 @@ int main(int argc, char *argv[]) {
     glm_mat4_print(view, stdout);
     glm_mat4_print(projection, stdout);
 
+    float speeds[10];
+    for (int i=0; i<LEN(speeds); ++i) {
+        speeds[i] = RANDOM(360);
+    }
+    assert(LEN(cubePositions)==LEN(speeds));
+
     while (1) {
         while (XPending(dpy)) {
             XEvent xev;
@@ -289,11 +300,13 @@ int main(int argc, char *argv[]) {
             }
         }
 
+        double t = current_ts()-t_started;
+
         glClearColor(0.1f, 0.1f, 0.15f, 1.0f);
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
         GLfloat iTime = glGetUniformLocation(shaderPrg, "iTime");
-        glUniform1d(iTime, current_ts()-t_started);
+        glUniform1d(iTime, t);
         //printf("%f\n", fabsf(sinf(current_ts()-t_started)));
 
         //glm_rotate(model, glm_rad(1.f), (vec3){0.5f, 1.f, 0.f});
@@ -308,15 +321,15 @@ int main(int argc, char *argv[]) {
         glUniform1i(tex, 0);
         glActiveTexture(GL_TEXTURE0);
         glBindTexture(GL_TEXTURE_2D, tex);
-        for (int i=0; i<sizeof(cubePositions)/sizeof(cubePositions[0]); ++i) {
+        for (int i=0; i<LEN(cubePositions); ++i) {
             mat4 model;
             glm_mat4_identity(model);
             glm_translate(model, cubePositions[i]);
-            GLfloat angle = 20.f * i + (current_ts()-t_started)*50;
+            GLfloat angle = 20.f * i + speeds[i]*t;
             glm_rotate(model, glm_rad(angle), (vec3){ 1.f, 0.3f, 0.5f });
             GLuint loc_model = glGetUniformLocation(shaderPrg, "model");
             glUniformMatrix4fv(loc_model, 1, GL_FALSE, model[0]);
-            glDrawArrays(GL_TRIANGLES, 0, sizeof(vertices)/sizeof(vertices[0]));
+            glDrawArrays(GL_TRIANGLES, 0, LEN(vertices));
         }
 
         glXSwapBuffers(dpy, win);