command line argument to shader

fragment.glsl

@@ -78,10 +78,7 @@ void main() {
     // lerp index
     float u = fade(tile_uv.x);
     float v = fade(tile_uv.y);
-    //float u = tile_uv.x;
-    //float v = tile_uv.y;
     float val = lerp(lerp(c_tl_dot, c_bl_dot, v), lerp(c_tr_dot, c_br_dot, v), u);
     float out_val = val /2.0 + 0.5;
-    //float out_val = rand(uv , vec2(1.0, 1.0));
     color = vec4(out_val, out_val, out_val, 1.0);
 }

glonkers.c

@@ -1,7 +1,7 @@
 #include <stdio.h>
+#include <stdlib.h>
 #include <time.h> 
 #include <stdint.h>
-#include <string.h>
 #include <wayland-client.h>
 #include <wayland-util.h>
 #include <SDL3/SDL.h>
@@ -79,7 +79,7 @@ double time_since_start() {
            (now.tv_nsec - program_start.tv_nsec) / 1e9;
 }
 
-int main() {
+int main(int argc, char *argv[]) {
     init_timer();
 
     printf("Good Morning 🍵\n");
@@ -119,8 +119,16 @@ int main() {
             }
         }
 
+        char *shader_path = NULL;
+        if (argc >= 2) {
+            shader_path = argv[1];
+        } else {
+            printf("need to supply path to shader\n");
+            exit(1);
+        }
+
         double time = time_since_start();
-        render(&renderer,  w, h, time);
+        render(&renderer, w, h, time, shader_path);
 
         SDL_GL_SwapWindow(window);
     }

renderer.c

@@ -1,5 +1,6 @@
 #define GL_GLEXT_PROTOTYPES
 #include <stdio.h>
+#include <string.h>
 #include <GL/gl.h>
 #include <stdlib.h>
 #include "renderer.h"
@@ -106,8 +107,6 @@ Renderer new_renderer() {
 
     glEnable(GL_DEPTH_TEST);
 
-    GLuint shader = load_shader("fragment.glsl"); //create_shader(fragment_shader_source);
-
     // buffers
     // Load the vertex data
     GLfloat vertices[] = {
@@ -139,11 +138,16 @@ Renderer new_renderer() {
         (void *)0
     );
 
-    Renderer renderer = { shader, vao };
+    Renderer renderer = { "", 0, vao };
     return renderer;
 }
 
-void render(Renderer *state, int w, int h, double time) {
+/// shader_path cannot be NULL.
+void render(Renderer *state, int w, int h, double time, char *shader_path) {
+    if (strcmp(state->shader_path, shader_path)) {
+        state->shader = load_shader(shader_path);
+    }
+
     checkGlError();
 
     // Rendorrrr

renderer.h

@@ -2,12 +2,13 @@
 #define RENDERER_H
 
 typedef struct Renderer {
+    char *shader_path;
     unsigned int shader;
     unsigned int vao;
 } Renderer;
 
 Renderer new_renderer();
-void render(Renderer *renderer, int w, int h, double time);
+void render(Renderer *renderer, int w, int h, double time, char *shader_path);
 
 #endif
 

run.sh

@@ -0,0 +1,3 @@
+make
+./glonkers "$@"
+