gles triangle

Makefile

@@ -6,4 +6,4 @@ all:
 	$(CC) $(CFLAGS) $(LDFLAGS) -o glonkers main.c
 
 run: all
-	./glonkers
+	SDL_VIDEODRIVER="wayland,x11" ./glonkers

fragment.glsl

@@ -1,69 +1,76 @@
-#version 330 core
+precision mediump float;
-out vec4 FragColor;
-uniform vec2 WindowSize;
-uniform float time;
-
-float rand(ivec2 co) {
-    return fract(sin(dot(co, vec2(12.9898, 78.233))) * 43758.5453);
-}
-
-float cell_size = 0.01;
-
-#define PI 3.1415926538
-
-// whatever that corner contributes
-float c_dot(vec2 point, vec2 corner) {
-    ivec2 c = ivec2(round(corner * 100));
-    float angle = rand(c) * 2*PI;
-    vec2 random_corner_vec = vec2(cos(angle), sin(angle));
-    vec2 offset = (point - corner) / cell_size;
-    float dot_product = dot(random_corner_vec, offset);
-    // for now just return something
-    return dot_product;
-}
-
-float lerp(float a, float b, float x) {
-    return a + x*(b-a);
-}
-
-// better than built in smoothstep.
-float fade(float t) {
-	return ((6*t - 15)*t + 10)*t*t*t;
-}
 
 void main() {
-    // We'll make origin in the top-left.
+    gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
-    vec2 uv = gl_FragCoord.xy / WindowSize;
-    uv.y = 1.0 - uv.y;
-    vec2 grid_edge_offset = mod(uv, cell_size);
-    // c: corner
-    vec2 c_tl = uv - grid_edge_offset;
-    vec2 c_tr = uv - grid_edge_offset + vec2(cell_size, 0);
-    vec2 c_bl = uv - grid_edge_offset + vec2(0,         cell_size);
-    vec2 c_br = uv - grid_edge_offset + vec2(cell_size, cell_size);
-    float c_tl_dot = c_dot(uv, c_tl);
-    float c_tr_dot = c_dot(uv, c_tr);
-    float c_bl_dot = c_dot(uv, c_bl);
-    float c_br_dot = c_dot(uv, c_br);
-
-    // the uv within the tile (0 to 1)
-    vec2 tile_uv = (uv - c_tl) / cell_size;
-
-    // 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 u = smoothstep(0, 1, tile_uv.x);
-    //float v = smoothstep(0, 1, tile_uv.y);
-    //float val = smoothstep(tile_uv.x, smoothstep(tile_uv.y, c_bl_dot, c_tl_dot), smoothstep(tile_uv.y, c_br_dot, c_tr_dot));
-    float val = lerp(lerp(c_tl_dot, c_bl_dot, v), lerp(c_tr_dot, c_br_dot, v), u);
-    //float val = tile_uv.y;
-    //float val = c_bl_dot*2 + 0.5;
-    //val = val * 20;
-    float out_val = val /2 + 0.5;
-    FragColor = vec4(out_val, out_val, out_val, 1);
-
-    //float yes = 0.5 + (c_dot(uv, c_tl) + c_dot(uv, c_tr) + c_dot(uv, c_bl) + c_dot(uv, c_br)) / 2;
-    //FragColor = vec4(yes, yes, yes, 1);
 } 
+
+
+//#version 330 core
+//out vec4 FragColor;
+//uniform vec2 WindowSize;
+//uniform float time;
+//
+//float rand(ivec2 co) {
+//    return fract(sin(dot(co, vec2(12.9898, 78.233))) * 43758.5453);
+//}
+//
+//float cell_size = 0.01;
+//
+//#define PI 3.1415926538
+//
+//// whatever that corner contributes
+//float c_dot(vec2 point, vec2 corner) {
+//    ivec2 c = ivec2(round(corner * 100));
+//    float angle = rand(c) * 2*PI;
+//    vec2 random_corner_vec = vec2(cos(angle), sin(angle));
+//    vec2 offset = (point - corner) / cell_size;
+//    float dot_product = dot(random_corner_vec, offset);
+//    // for now just return something
+//    return dot_product;
+//}
+//
+//float lerp(float a, float b, float x) {
+//    return a + x*(b-a);
+//}
+//
+//// better than built in smoothstep.
+//float fade(float t) {
+//	return ((6*t - 15)*t + 10)*t*t*t;
+//}
+//
+//void main() {
+//    // We'll make origin in the top-left.
+//    vec2 uv = gl_FragCoord.xy / WindowSize;
+//    uv.y = 1.0 - uv.y;
+//    vec2 grid_edge_offset = mod(uv, cell_size);
+//    // c: corner
+//    vec2 c_tl = uv - grid_edge_offset;
+//    vec2 c_tr = uv - grid_edge_offset + vec2(cell_size, 0);
+//    vec2 c_bl = uv - grid_edge_offset + vec2(0,         cell_size);
+//    vec2 c_br = uv - grid_edge_offset + vec2(cell_size, cell_size);
+//    float c_tl_dot = c_dot(uv, c_tl);
+//    float c_tr_dot = c_dot(uv, c_tr);
+//    float c_bl_dot = c_dot(uv, c_bl);
+//    float c_br_dot = c_dot(uv, c_br);
+//
+//    // the uv within the tile (0 to 1)
+//    vec2 tile_uv = (uv - c_tl) / cell_size;
+//
+//    // 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 u = smoothstep(0, 1, tile_uv.x);
+//    //float v = smoothstep(0, 1, tile_uv.y);
+//    //float val = smoothstep(tile_uv.x, smoothstep(tile_uv.y, c_bl_dot, c_tl_dot), smoothstep(tile_uv.y, c_br_dot, c_tr_dot));
+//    float val = lerp(lerp(c_tl_dot, c_bl_dot, v), lerp(c_tr_dot, c_br_dot, v), u);
+//    //float val = tile_uv.y;
+//    //float val = c_bl_dot*2 + 0.5;
+//    //val = val * 20;
+//    float out_val = val /2 + 0.5;
+//    FragColor = vec4(out_val, out_val, out_val, 1);
+//
+//    //float yes = 0.5 + (c_dot(uv, c_tl) + c_dot(uv, c_tr) + c_dot(uv, c_bl) + c_dot(uv, c_br)) / 2;
+//    //FragColor = vec4(yes, yes, yes, 1);
+//}

main.c

@@ -5,10 +5,11 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
+#include <EGL/egl.h>
 #include <GL/gl.h>
 #include <wayland-client.h>
 #include <wayland-util.h>
-//#include <SDL3/SDL.h>
+#include <SDL3/SDL.h>
 
 //int main() {
 //    struct wl_display *display = wl_display_connect(NULL);
@@ -23,208 +24,231 @@
 //
 //    wl_display_disconnect(display);
 //}
-struct our_state {
+//struct our_state {
-    // ...
+//    // ...
-    struct wl_compositor *compositor;
+//    struct wl_compositor *compositor;
-    // ...
+//    // ...
-};
+//};
+//
+//static void
+//registry_handle_global(void *data, struct wl_registry *registry,
+//		uint32_t name, const char *interface, uint32_t version)
+//{
+//	printf("interface: '%s', version: %d, name: %d\n",
+//			interface, version, name);
+//
+//    struct our_state *state = data;
+//
+//    if (strcmp(interface, wl_compositor_interface.name) == 0) {
+//        state->compositor = wl_registry_bind(
+//            registry, name, &wl_compositor_interface, 4);
+//    }
+//}
+//
+//static void
+//registry_handle_global_remove(void *data, struct wl_registry *registry,
+//		uint32_t name)
+//{
+//	// This space deliberately left blank
+//}
+//
+//static const struct wl_registry_listener
+//registry_listener = {
+//	.global = registry_handle_global,
+//	.global_remove = registry_handle_global_remove,
+//};
+//
+//int
+//main(int argc, char *argv[])
+//{
+//    struct our_state state = { 0 };
+//	struct wl_display *display = wl_display_connect(NULL);
+//	struct wl_registry *registry = wl_display_get_registry(display);
+//    wl_registry_add_listener(registry, &registry_listener, &state);
+//	wl_display_roundtrip(display);
+//	return 0;
+//}
 
-static void
+void checkGlError() {
-registry_handle_global(void *data, struct wl_registry *registry,
+    const char *err = SDL_GetError();
-		uint32_t name, const char *interface, uint32_t version)
+    if (*err != 0) {
-{
+        printf("OpenGL error: %s", err);
-	printf("interface: '%s', version: %d, name: %d\n",
-			interface, version, name);
-
-    struct our_state *state = data;
-
-    if (strcmp(interface, wl_compositor_interface.name) == 0) {
-        state->compositor = wl_registry_bind(
-            registry, name, &wl_compositor_interface, 4);
     }
 }
 
-static void
+/// returns 0 if failed.
-registry_handle_global_remove(void *data, struct wl_registry *registry,
+GLuint compile_shader(GLuint type, const char *src) {
-		uint32_t name)
+    GLuint id = glCreateShader(type);
-{
+    glShaderSource(id, 1, &src, 0);
-	// This space deliberately left blank
+    glCompileShader(id);
+
+    int result;
+    glGetShaderiv(id, GL_COMPILE_STATUS, &result);
+    if (result == GL_FALSE) {
+        int length;
+        glGetShaderiv(id, GL_INFO_LOG_LENGTH, &result);
+        char *message = alloca(length * sizeof(char));
+        glGetShaderInfoLog(id, length, &length, message);
+        printf("failed to compile %s shader\n", type == GL_VERTEX_SHADER ? "vertex" : "fragment");
+        printf("%s\n", message);
+        glDeleteShader(id);
+        return 0;
+    }
+
+    return id;
 }
 
-static const struct wl_registry_listener
+const char *vertex_shader_src =
-registry_listener = {
+"attribute vec4 vPosition; \n"
-	.global = registry_handle_global,
+"void main() \n"
-	.global_remove = registry_handle_global_remove,
+"{ \n"
-};
+" gl_Position = vPosition; \n"
+"} \n";
 
-int
+/// returns 0 if failed.
-main(int argc, char *argv[])
+GLuint create_shader(const char *fragment_src) {
-{
+    GLuint program = glCreateProgram();
-    struct our_state state = { 0 };
+    GLuint vertex_shader = compile_shader(GL_VERTEX_SHADER, vertex_shader_src);
-	struct wl_display *display = wl_display_connect(NULL);
+    GLuint fragment_shader = compile_shader(GL_FRAGMENT_SHADER, fragment_src);
-	struct wl_registry *registry = wl_display_get_registry(display);
+    if (!((fragment_shader == 0) || (vertex_shader == 0))) {
-    wl_registry_add_listener(registry, &registry_listener, &state);
+        glAttachShader(program, vertex_shader);
-	wl_display_roundtrip(display);
+        glAttachShader(program, fragment_shader);
-	return 0;
+        glLinkProgram(program);
+        glValidateProgram(program);
+        glDeleteShader(vertex_shader);
+        glDeleteShader(fragment_shader);
+        return program;
+    } else {
+        return 0;
+    }
+}
+
+GLuint load_shader(const char *path) {
+    FILE *handle = fopen(path, "r");
+    fseek(handle, 0L, SEEK_END);
+    long length = ftell(handle);
+    fseek(handle, 0L, SEEK_SET);
+    char *string = malloc(length * sizeof(char));
+    if (!fread(string, sizeof(char), length, handle)) {
+        printf("failed to read shader file");
+        exit(1);
+    }
+    fclose(handle);
+
+    GLuint shader = create_shader(string);
+
+    if (shader == 0) {
+        // print file
+        int line_count = 1;
+        printf("%i\t", line_count);
+        line_count++;
+        for (int i = 0; i < length; i++) {
+            printf("%c", string[i]);
+            if (string[i] == '\n') {
+                printf("%i\t", line_count);
+                line_count++;
+            }
+        }
+        printf("\n");
+    }
+
+    free(string);
+    return shader;
+}
+
+struct timespec program_start;
+
+void init_timer() {
+    clock_gettime(CLOCK_MONOTONIC, &program_start);
+}
+
+double time_since_start() {
+    struct timespec now;
+    clock_gettime(CLOCK_MONOTONIC, &now);
+
+    return (now.tv_sec - program_start.tv_sec) +
+           (now.tv_nsec - program_start.tv_nsec) / 1e9;
+}
+
+int main() {
+    init_timer();
+
+    printf("Good Morning 🍵\n");
+    SDL_Init(SDL_INIT_VIDEO);
+    SDL_SetHint(SDL_HINT_OPENGL_ES_DRIVER, "1");
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK,
+        SDL_GL_CONTEXT_PROFILE_ES);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+    SDL_Window* window = SDL_CreateWindow("SDL3 OpenGL Cube",
+    800, 600, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
+    if (!window) {
+        printf("CreateWindow Error: %s\n", SDL_GetError());
+        SDL_Quit();
+        return 1;
+    }
+    
+    SDL_GLContext glContext = SDL_GL_CreateContext(window);
+const char *version = (const char *)glGetString(GL_VERSION);
+const char *renderer = (const char *)glGetString(GL_RENDERER);
+
+SDL_Log("GL_VERSION: %s", version);
+SDL_Log("GL_RENDERER: %s", renderer);
+
+    if (!glContext) {
+        printf("GL Context Error: %s\n", SDL_GetError());
+        SDL_DestroyWindow(window);
+        SDL_Quit();
+        return 1;
+    }
+    glEnable(GL_DEPTH_TEST);
+
+    SDL_Event e;
+    int running = 1;
+
+    GLuint shader = load_shader("fragment.glsl"); //create_shader(fragment_shader_source);
+
+    int w, h;
+    double time;
+    while (running) {
+        while (SDL_PollEvent(&e)) {
+            if (e.type == SDL_EVENT_QUIT) running = false;
+            if (e.type == SDL_EVENT_WINDOW_RESIZED) {
+                SDL_GetWindowSize(window, &w, &h);
+            }
+        }
+        checkGlError();
+
+        // Rendorrrr
+        glViewport(0, 0, w, h);
+
+        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);  // Dark gray background
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // Shader parameters.
+        glUseProgram(shader);
+        
+        //int uniform_WindowSize = glGetUniformLocation(shader, "WindowSize");
+        //glUniform2f(uniform_WindowSize, w, h);
+
+        //time = time_since_start();
+        //int uniform_time = glGetUniformLocation(shader, "time");
+        //glUniform1f(uniform_time, (float)time);
+
+        // Load the vertex data
+        GLfloat vVertices[] = {
+            0.0f, 0.5f, 0.0f,
+            -0.5f, -0.5f, 0.0f,
+            0.5f, -0.5f, 0.0f
+        };
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, vVertices);
+        glEnableVertexAttribArray(0);
+        glDrawArrays(GL_TRIANGLES, 0, 3);
+
+        SDL_GL_SwapWindow(window);
+        checkGlError();
+    }
+
+    checkGlError();
 }
 
-//void checkGlError() {
-//    const char *err = SDL_GetError();
-//    if (*err != 0) {
-//        printf("OpenGL error: %s", err);
-//    }
-//}
-//
-///// returns 0 if failed.
-//GLuint compile_shader(GLuint type, const char *src) {
-//    GLuint id = glCreateShader(type);
-//    glShaderSource(id, 1, &src, 0);
-//    glCompileShader(id);
-//
-//    int result;
-//    glGetShaderiv(id, GL_COMPILE_STATUS, &result);
-//    if (result == GL_FALSE) {
-//        int length;
-//        glGetShaderiv(id, GL_INFO_LOG_LENGTH, &result);
-//        char *message = alloca(length * sizeof(char));
-//        glGetShaderInfoLog(id, length, &length, message);
-//        printf("failed to compile %s shader\n", type == GL_VERTEX_SHADER ? "vertex" : "fragment");
-//        printf("%s\n", message);
-//        glDeleteShader(id);
-//        return 0;
-//    }
-//
-//    return id;
-//}
-//
-///// returns 0 if failed.
-//GLuint create_shader(const char *fragment_src) {
-//    GLuint program = glCreateProgram();
-//    GLuint fragment_shader = compile_shader(GL_FRAGMENT_SHADER, fragment_src);
-//    if (!(fragment_shader == 0)) {
-//        glAttachShader(program, fragment_shader);
-//        glLinkProgram(program);
-//        glValidateProgram(program);
-//        glDeleteShader(fragment_shader);
-//        return program;
-//    } else {
-//        return 0;
-//    }
-//}
-//
-//GLuint load_shader(const char *path) {
-//    FILE *handle = fopen(path, "r");
-//    fseek(handle, 0L, SEEK_END);
-//    long length = ftell(handle);
-//    fseek(handle, 0L, SEEK_SET);
-//    char *string = malloc(length * sizeof(char));
-//    if (!fread(string, sizeof(char), length, handle)) {
-//        printf("failed to read shader file");
-//        exit(1);
-//    }
-//    fclose(handle);
-//
-//    GLuint shader = create_shader(string);
-//
-//    if (shader == 0) {
-//        // print file
-//        int line_count = 1;
-//        printf("%i\t", line_count);
-//        line_count++;
-//        for (int i = 0; i < length; i++) {
-//            printf("%c", string[i]);
-//            if (string[i] == '\n') {
-//                printf("%i\t", line_count);
-//                line_count++;
-//            }
-//        }
-//        printf("\n");
-//    }
-//
-//    free(string);
-//    return shader;
-//}
-//
-//struct timespec program_start;
-//
-//void init_timer() {
-//    clock_gettime(CLOCK_MONOTONIC, &program_start);
-//}
-//
-//double time_since_start() {
-//    struct timespec now;
-//    clock_gettime(CLOCK_MONOTONIC, &now);
-//
-//    return (now.tv_sec - program_start.tv_sec) +
-//           (now.tv_nsec - program_start.tv_nsec) / 1e9;
-//}
-//
-//int main() {
-//    init_timer();
-//
-//    printf("Good Morning 🍵\n");
-//    SDL_Init(SDL_INIT_VIDEO);
-//    SDL_Window* window = SDL_CreateWindow("SDL3 OpenGL Cube",
-//    800, 600, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
-//    if (!window) {
-//        printf("CreateWindow Error: %s\n", SDL_GetError());
-//        SDL_Quit();
-//        return 1;
-//    }
-//    
-//    SDL_GLContext glContext = SDL_GL_CreateContext(window);
-//    if (!glContext) {
-//        printf("GL Context Error: %s\n", SDL_GetError());
-//        SDL_DestroyWindow(window);
-//        SDL_Quit();
-//        return 1;
-//    }
-//    glEnable(GL_DEPTH_TEST);
-//
-//    SDL_Event e;
-//    int running = 1;
-//
-//    GLuint shader = load_shader("fragment.glsl"); //create_shader(fragment_shader_source);
-//
-//    int w, h;
-//    double time;
-//    while (running) {
-//        while (SDL_PollEvent(&e)) {
-//            if (e.type == SDL_EVENT_QUIT) running = false;
-//            if (e.type == SDL_EVENT_WINDOW_RESIZED) {
-//                SDL_GetWindowSize(window, &w, &h);
-//            }
-//        }
-//        checkGlError();
-//
-//        // Rendorrrr
-//        glViewport(0, 0, w, h);
-//
-//        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);  // Dark gray background
-//        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-//
-//        // Shader parameters.
-//        glUseProgram(shader);
-//        
-//        int uniform_WindowSize = glGetUniformLocation(shader, "WindowSize");
-//        glUniform2f(uniform_WindowSize, w, h);
-//
-//        time = time_since_start();
-//        int uniform_time = glGetUniformLocation(shader, "time");
-//        glUniform1f(uniform_time, (float)time);
-//
-//        // Draw quad.
-//        glBegin(GL_QUADS);
-//        glVertex2f(-1, 1);
-//        glVertex2f(-1,-1);
-//        glVertex2f( 1,-1);
-//        glVertex2f( 1, 1);
-//
-//        glEnd();
-//
-//        SDL_GL_SwapWindow(window);
-//    }
-//
-//    checkGlError();
-//}
-//