Updated project status

README.org

@@ -1,15 +1,15 @@
 * Todo list
-  - [ ] Create arena allocator
+  - [X] Create arena allocator
   - [ ] Create dynamic arrays using arena allocator
-  - [ ] Create stack function caller for calling library deallocators
+  - [X] Create stack function caller for calling library deallocators
   - [ ] Create method of storing models and model data
   - [ ] implement textures and simple lighting
   - [ ] Figure out a simple game to make with this engine
 
 * TODO Arena Allocator Requirements
-  - [ ] Sub arenas
-  - [x] Arena infinite growth (not contiguos)
-  - [ ] contiguos memory spaces for dynamic arrays that grow larger than the arena size
+  - [X] Sub arenas
+  - [x] Arena infinite growth (not contiguous)
+  - [ ] contiguous memory spaces for dynamic arrays that grow larger than the arena size
 ** Optional
    - [ ] free lists to reuse abandoned chunks of memory arenas
 

src/arena_allocator.c

@@ -6,6 +6,12 @@
 
 #define DEFAUL_REGION_SIZE 1048576 /* 8 * 1024 * 1024 = 8MB */
 
+struct ArenaDeinitTask_s {
+  void *func_param;
+  void (*func_ptr)(void *);
+  ArenaDeinitTask *next;
+};
+
 Region *new_region(size_t capacity) {
   if (capacity < DEFAUL_REGION_SIZE) {
     capacity = DEFAUL_REGION_SIZE;
@@ -126,9 +132,11 @@ void *arena_alloc(Arena *arena, size_t size) {
   return result;
 }
 
-void arena_deinit_task_push(Arena *arena, ArenaDeinitTask task) {
+void arena_deinit_task_push(Arena *arena, void *func_param,
+                            void (*func_ptr)(void *)) {
   ArenaDeinitTask *job = arena_alloc(arena, sizeof(ArenaDeinitTask));
-  *job = task;
+  *job = (ArenaDeinitTask){
+      .func_ptr = func_ptr, .func_param = func_param, .next = NULL};
 
   ArenaDeinitTask *next_job = arena->deinit_task_top;
   arena->deinit_task_top = job;

src/arena_allocator.h

@@ -10,12 +10,8 @@ struct Region_s {
   unsigned char data[];
 };
 
+struct ArenaDeinitTask_s;
 typedef struct ArenaDeinitTask_s ArenaDeinitTask;
-struct ArenaDeinitTask_s {
-  void *func_param;
-  void (*func_ptr)(void *);
-  ArenaDeinitTask *next;
-};
 
 typedef struct Arena_s Arena;
 struct Arena_s {
@@ -30,7 +26,8 @@ struct Arena_s {
 Arena *arena_init(Arena *parent, size_t capacity);
 void arena_deinit(Arena *arena);
 
-void arena_deinit_task_push(Arena *arena, ArenaDeinitTask task);
+void arena_deinit_task_push(Arena *arena, void *func_param,
+                            void (*func_ptr)(void *));
 
 void *arena_alloc(Arena *arena, size_t size);
 // void *arena_clear(Arena *arena);

src/main.c

@@ -12,6 +12,7 @@
 #include "window.h"
 
 #include "arena_allocator.h"
+#include "mesh.h"
 
 /*
 void test_task(void *data) {
@@ -77,7 +78,7 @@ int main(int argc, char *argv[]) {
     return EXIT_FAILURE;
   }
 
-  // set up vertex data (and buffer(s)) and configure vertex attributes
+// Set up mesh data
   float vertices[] = {
       0.5f,  0.5f,  0.0f, 1.0f, 1.0f, // top right
       0.5f,  -0.5f, 0.0f, 1.0f, 0.0f, // bottom right
@@ -89,75 +90,12 @@ int main(int argc, char *argv[]) {
       1, 2, 3  // second Triangle
   };
 
-  unsigned int VBO, VAO, EBO;
-  glGenVertexArrays(1, &VAO);
-  glGenBuffers(1, &VBO);
-  glGenBuffers(1, &EBO);
-  // bind the Vertex Array Object first, then bind and set vertex buffer(s), and
-  // then configure vertex attributes(s).
-  glBindVertexArray(VAO);
-
-  glBindBuffer(GL_ARRAY_BUFFER, VBO);
-  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
-  glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,
-               GL_STATIC_DRAW);
-
-  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void *)0);
-  glEnableVertexAttribArray(0);
-  glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float),
-                        (void *)(3 * sizeof(float)));
-  glEnableVertexAttribArray(1);
-
-  // note that this is allowed, the call to glVertexAttribPointer registered VBO
-  // as the vertex attribute's bound vertex buffer object so afterwards we can
-  // safely unbind
-  // glBindBuffer(GL_ARRAY_BUFFER, 0);
-
-  // remember: do NOT unbind the EBO while a VAO is active as the bound element
-  // buffer object IS stored in the VAO; keep the EBO bound.
-  // glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
-
-  // You can unbind the VAO afterwards so other VAO calls won't accidentally
-  // modify this VAO, but this rarely happens. Modifying other VAOs requires a
-  // call to glBindVertexArray anyways so we generally don't unbind VAOs (nor
-  // VBOs) when it's not directly necessary.
-  // glBindVertexArray(0);
-
-  // Texture Load
-  SDL_Surface *image = IMG_Load("./data/testxure.png");
-  if (image == NULL) {
-    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load texture");
+  // Create mesh
+  wn_mesh *mesh = wn_mesh_init(global_arena, vertices, 20, indices, 6, "./data/testxure.png");
+  if (mesh == NULL) {
+    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize mesh");
     return EXIT_FAILURE;
   }
-  SDL_FlipSurface(image, SDL_FLIP_VERTICAL);
-
-  GLuint texture;
-  glActiveTexture(GL_TEXTURE0);
-  glGenTextures(1, &texture);
-
-  // Handle different SDL Surface data types
-  int mode = GL_RGBA;
-  //  if (image->format->BytesPerPixel == 4) {
-  //    mode = GL_RGBA;
-  //  }
-
-  glBindTexture(GL_TEXTURE_2D, texture);
-  // set the texture wrapping parameters
-  glTexParameteri(
-      GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
-      GL_REPEAT); // set texture wrapping to GL_REPEAT (default wrapping method)
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
-  // set texture filtering parameters
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-
-  glTexImage2D(GL_TEXTURE_2D, 0, mode, image->w, image->h, 0, mode,
-               GL_UNSIGNED_BYTE, image->pixels);
-
-  glGenerateMipmap(GL_TEXTURE_2D);
-  SDL_DestroySurface(image);
 
   // Initialise camera
   Camera camera = Camera_default;
@@ -196,23 +134,14 @@ int main(int argc, char *argv[]) {
     glClearColor(0.1f, 0.3f, 0.4f, 1.f);
     glClear(GL_COLOR_BUFFER_BIT);
 
-    // draw our first triangle
+    // draw our mesh
     glUseProgram(shader->shaderProgram);
-
-    // seeing as we only have a single VAO there's no need to bind it
-    // every time, but we'll do so to keep things a bit more organized
-    glBindVertexArray(VAO);
-
-    // glDrawArrays(GL_TRIANGLES, 0, 6);
-    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
-    // glBindVertexArray(0); // no need to unbind it every time
+    wn_mesh_draw(mesh);
 
     wn_swapwindow(window);
   }
 
-  glDeleteVertexArrays(1, &VAO);
-  glDeleteBuffers(1, &VBO);
-  glDeleteBuffers(1, &EBO);
+  // Mesh cleanup is handled by arena deinit tasks
 
   arena_deinit(global_arena);
   return EXIT_SUCCESS;

src/mesh.c

@@ -0,0 +1,116 @@
+#include "mesh.h"
+#include <SDL3/SDL.h>
+#include <SDL3/SDL_log.h>
+#include <SDL3/SDL_surface.h>
+#include <SDL3_image/SDL_image.h>
+#include <stdlib.h>
+
+void wn_mesh_deinit(wn_mesh *mesh) {
+  if (mesh == NULL) {
+    return;
+  }
+
+  glDeleteVertexArrays(1, &mesh->VAO);
+  glDeleteBuffers(1, &mesh->VBO);
+  glDeleteBuffers(1, &mesh->EBO);
+  if (mesh->texture != 0) {
+    glDeleteTextures(1, &mesh->texture);
+  }
+}
+
+wn_mesh *wn_mesh_init(Arena *arena, const float *vertices, size_t vertex_count,
+                      const unsigned int *indices, size_t index_count,
+                      const char *texture_path) {
+  wn_mesh *mesh = arena_alloc(arena, sizeof(wn_mesh));
+
+  // Generate OpenGL objects
+  glGenVertexArrays(1, &mesh->VAO);
+  glGenBuffers(1, &mesh->VBO);
+  glGenBuffers(1, &mesh->EBO);
+
+  // Store counts
+  mesh->vertex_count = vertex_count;
+  mesh->index_count = index_count;
+  mesh->texture = 0;
+
+  // Bind VAO first
+  glBindVertexArray(mesh->VAO);
+
+  // Set up VBO
+  glBindBuffer(GL_ARRAY_BUFFER, mesh->VBO);
+  glBufferData(GL_ARRAY_BUFFER, vertex_count * sizeof(float), vertices,
+               GL_STATIC_DRAW);
+
+  // Set up EBO
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh->EBO);
+  glBufferData(GL_ELEMENT_ARRAY_BUFFER, index_count * sizeof(unsigned int),
+               indices, GL_STATIC_DRAW);
+
+  // Set vertex attributes
+  // Position attribute (location = 0)
+  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void *)0);
+  glEnableVertexAttribArray(0);
+
+  // Texture coordinate attribute (location = 1)
+  glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float),
+                        (void *)(3 * sizeof(float)));
+  glEnableVertexAttribArray(1);
+
+  // Load texture if path provided
+  if (texture_path != NULL) {
+    SDL_Surface *image = IMG_Load(texture_path);
+    if (image == NULL) {
+      SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load texture: %s",
+                   texture_path);
+      wn_mesh_deinit(mesh);
+      return NULL;
+    }
+
+    SDL_FlipSurface(image, SDL_FLIP_VERTICAL);
+
+    glActiveTexture(GL_TEXTURE0);
+    glGenTextures(1, &mesh->texture);
+
+    // Determine texture format
+    int mode = GL_RGBA;
+
+    glBindTexture(GL_TEXTURE_2D, mesh->texture);
+
+    // Set texture parameters
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+    // Upload texture data
+    glTexImage2D(GL_TEXTURE_2D, 0, mode, image->w, image->h, 0, mode,
+                 GL_UNSIGNED_BYTE, image->pixels);
+    glGenerateMipmap(GL_TEXTURE_2D);
+
+    SDL_DestroySurface(image);
+  }
+
+  // Unbind VAO
+  glBindVertexArray(0);
+
+  arena_deinit_task_push(arena, mesh, (void (*)(void *))wn_mesh_deinit);
+
+  return mesh;
+}
+
+void wn_mesh_draw(wn_mesh *mesh) {
+  if (mesh == NULL) {
+    return;
+  }
+
+  // Bind texture if available
+  if (mesh->texture != 0) {
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, mesh->texture);
+  }
+
+  // Bind VAO and draw
+  glBindVertexArray(mesh->VAO);
+  glDrawElements(GL_TRIANGLES, mesh->index_count, GL_UNSIGNED_INT, 0);
+  glBindVertexArray(0);
+}

src/mesh.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "arena_allocator.h"
+#include <GL/glew.h>
+#include <stddef.h>
+
+typedef struct wn_mesh wn_mesh;
+
+struct wn_mesh {
+  unsigned int VAO;
+  unsigned int VBO;
+  unsigned int EBO;
+  unsigned int vertex_count;
+  unsigned int index_count;
+  GLuint texture;
+};
+
+wn_mesh *wn_mesh_init(Arena *arena, const float *vertices, size_t vertex_count,
+                      const unsigned int *indices, size_t index_count,
+                      const char *texture_path);
+void wn_mesh_draw(wn_mesh *mesh);
+void wn_mesh_deinit(wn_mesh *mesh);

src/shader.c

@@ -67,13 +67,12 @@ wn_shader *wn_shader_init(Arena *arena,
   shader->shaderProgram = shaderProgram;
   shader->success = true;
 
-  arena_deinit_task_push(arena, (ArenaDeinitTask){.func_ptr = *wn_shader_deinit,
-                                                  .func_param = shader,
-                                                  .next = NULL});
+  arena_deinit_task_push(arena, (void *)shader,
+                         (void (*)(void *))wn_shader_deinit);
   return shader;
 }
 
-void wn_shader_deinit(void *shader) {
+void wn_shader_deinit(wn_shader *shader) {
   wn_shader *cast_shader = (wn_shader *)shader;
   glDeleteProgram(cast_shader->shaderProgram);
 }

src/shader.h

@@ -17,4 +17,4 @@ typedef struct wn_shader_s wn_shader;
 wn_shader *wn_shader_init(Arena *arena,
                           wn_shader_code_location shader_code_location);
 
-void wn_shader_deinit(void* shader);
+void wn_shader_deinit(wn_shader *shader);

src/window.c

@@ -56,15 +56,13 @@ wn_window *wn_window_init(Arena *arena) {
   SDL_SetWindowRelativeMouseMode(window->window, true);
   SDL_GetRelativeMouseState(NULL, NULL);
 
-  // add deinit function to arena deinit stack
-  arena_deinit_task_push(arena, (ArenaDeinitTask){.func_param = (void *)window,
-                                                  .func_ptr = *wn_window_deinit,
-                                                  .next = NULL});
+  arena_deinit_task_push(arena, (void *)window,
+                         (void (*)(void *))wn_window_deinit);
 
   return window;
 }
 
-void wn_window_deinit(void *window) {
+void wn_window_deinit(wn_window *window) {
   wn_window *cast_window = (wn_window *)window;
   SDL_GL_DestroyContext(cast_window->glcontext);
   SDL_DestroyWindow(cast_window->window);

src/window.h

@@ -15,6 +15,6 @@ struct wn_window_s {
 typedef struct wn_window_s wn_window;
 
 wn_window *wn_window_init(Arena *arena);
-void wn_window_deinit(void *window);
+void wn_window_deinit(wn_window *window);
 
 void wn_swapwindow(wn_window *window);