Major refactor

shaders/shader.frag

@@ -0,0 +1,8 @@
+#version 330
+
+in vec4 vertex_color;
+out vec4 color;
+
+void main() {
+    color = vertex_color;
+}

shaders/shader.vert

@@ -0,0 +1,13 @@
+#version 330
+
+layout (location = 0) in vec3 pos;
+
+out vec4 vertex_color;
+
+uniform mat4 projection;
+uniform mat4 model;
+
+void main() {
+    gl_Position = projection * model * vec4(pos, 1.0);
+    vertex_color = vec4(clamp(pos, 0.0f, 1.0f), 1.0f);
+}

src/file.cpp

@@ -0,0 +1,21 @@
+#include "file.h"
+
+std::string read_entire_file(const char *path) {
+  std::string content;
+	std::ifstream file_stream(path, std::ios::in);
+
+	if (!file_stream.is_open()) {
+		printf("Failed to read %s! File doesn't exist.", path);
+		return "";
+	}
+
+	std::string line = "";
+	while (!file_stream.eof())
+	{
+		std::getline(file_stream, line);
+		content.append(line + "\n");
+	}
+
+	file_stream.close();
+	return content;
+}

src/file.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <string>
+#include <iostream>
+#include <fstream>
+
+std::string read_entire_file(const char *path);

src/geometry.cpp

@@ -1,23 +0,0 @@
-#include "geometry.h"
-
-void create_triangle(GLuint *VAO, GLuint *VBO) {
-    GLfloat vertices[] = {
-        -1.0f, -1.0f, 0.0f,
-        1.0f, -1.0f, 0.0f,
-        0.0f, 1.0f, 0.0f
-    };
-
-    glGenVertexArrays(1, VAO);
-    glBindVertexArray(*VAO);
-
-    glGenBuffers(1, VBO);
-    glBindBuffer(GL_ARRAY_BUFFER, *VBO);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
-    glEnableVertexAttribArray(0);
-
-    // Unbinding
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-    glBindVertexArray(0);
-}

src/geometry.h

@@ -1,4 +0,0 @@
-#pragma once
-#include <GL/glew.h>
-
-void create_triangle(GLuint *VAO, GLuint *VBO);

src/main.cpp

@@ -1,112 +1,78 @@
-#include <GL/glew.h>
-#include <GLFW/glfw3.h>
-#include <cmath>
-#include <glm/glm.hpp>
-#include <glm/gtc/matrix_transform.hpp>
-#include <glm/gtc/type_ptr.hpp>
-
+#include "mesh.h"
 #include "shader.h"
-#include "geometry.h"
-#include "math.h"
 #include "window.h"
 
-// Window dimensions
+
+static const char *vertex_shader_code = "shaders/shader.vert";
+static const char *fragment_shader_code = "shaders/shader.frag";
 
 int main() {
-    GLuint VAO, VBO, shader_program, uniform_model;
-    bool direction = true;
-    float tri_offset = 0.0f;
-    float tri_max_offset = 0.7f;
-    float tri_increment = 0.005f;
-    float current_angle = 0.0f;
-    bool size_direction = true;
-    float current_size = 0.4f;
-    float max_size = 0.9f;
-    float min_size = 0.1f;
+  Mesh *meshes[10] = {nullptr};
+  Shader shaders[10];  
 
   Window window;
   bool success = setup_window(&window);
 
-    Shader vertex_shader;
-    vertex_shader.type = VERTEX;
-    vertex_shader.raw_code = "                                       \n\
-#version 330                                                         \n\
-                                                                     \n\
-layout (location = 0) in vec3 pos;                                   \n\
-                                                                     \n\
-uniform mat4 model;                                                  \n\
-                                                                     \n\
-void main() {                                                        \n\
-    gl_Position = model * vec4(pos, 1.0);                            \n\
-}";
+  {
+    // Create a mesh
+    f32 vertices[] = {
+      -1.0f, -1.0f, 0.0f,
+      0.0f, -1.0f, 1.0f,
+      1.0f,  -1.0f, 0.0f,
+      0.0f, 1.0f,  0.0f
+    };
 
-    Shader fragment_shader;
-    fragment_shader.type = FRAGMENT;
-    fragment_shader.raw_code = "                                     \n\
-#version 330                                                         \n\
-                                                                     \n\
-out vec4 color;                                                      \n\
-                                                                     \n\
-void main() {                                                        \n\
-    color = vec4(1.0, 0.0, 0.0, 1.0);                                \n\
-}";
+    u32 indices[] = {
+      0, 3, 1,
+      1, 3, 2,
+      2, 3, 0,
+      0, 1, 2
+    };
 
-    // Create our triangle
-    create_triangle(&VAO, &VBO);
-    compile_shaders(&shader_program, &uniform_model, &vertex_shader, &fragment_shader);
+    Mesh *triangle = new Mesh();
+    create_mesh(triangle, vertices, indices, 12, 12);
+    meshes[0] = triangle;
+  }
+
+  {
+    // Create a shader
+    Shader *shader = new Shader();
+    create_shader(shader, vertex_shader_code, fragment_shader_code);
+    shaders[0] = *shader;
+  }
+
+  Matrix4 projection = glm::perspective(
+      45.0f, (GLfloat)window.buffer_width / (GLfloat)window.buffer_height, 0.1f,
+      100.0f);
+
+  u32 uniform_projection = 0, uniform_model = 0;
+  f32 current_angle = 0.1f;
 
   // Loop until window is closed
   while (!glfwWindowShouldClose(window.gl_window)) {
     // Get and handle user input events
     glfwPollEvents();
 
-        if (direction) {
-            tri_offset += tri_increment;
-        } else {
-            tri_offset -= tri_increment;
-        }
-
-        if (std::abs(tri_offset) >= tri_max_offset) {
-            direction = !direction;
-        }
-
-        current_angle += 0.1f;
-
-        // This isn't necessary except for safety reasons
-        // the program will still run correctly, but if left open too
-        // long the number will overflow.
-        if (current_angle >= 360) {
-            current_angle -= 360;
-        }
-
-        if (size_direction) {
-            current_size += 0.01f;
-        } else {
-            current_size -= 0.01f;
-        }
-
-        if (current_size >= max_size || current_size <= min_size) {
-            size_direction = !size_direction;
-        }
-
     // Clear window
     glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-        glUseProgram(shader_program);
+    glUseProgram(shaders[0].id);
+    uniform_model = shaders[0].uniform_model;
+    uniform_projection = shaders[0].uniform_projection;
 
-        Matrix4 model = Matrix4(1.0f);
-        // The order of these matter
-        model = glm::translate(model, Vector3(tri_offset, 0.0f, 0.0f));
-        model = glm::scale(model, Vector3(current_size, 0.4f, 1.0f));
-        model = glm::rotate(model, current_angle * RADIAN_FACTOR, Vector3(0.0f, 0.0f, 1.0f));
+    Matrix4 model(1.0f);
+    model = glm::translate(model, Vector3(0.0f, 0.0f, -2.5f));
+    model = glm::rotate(model, current_angle * RADIAN_FACTOR, Vector3(0.0f, 1.0f, 0.0f));
+    model = glm::scale(model, Vector3(0.4f, 0.4f, 1.0f));
+
+    current_angle += 0.5f;
 
     glUniformMatrix4fv(uniform_model, 1, GL_FALSE, glm::value_ptr(model));
+    glUniformMatrix4fv(uniform_projection, 1, GL_FALSE, glm::value_ptr(projection));
 
-        glBindVertexArray(VAO);
-        glDrawArrays(GL_TRIANGLES, 0, 3);
+    render_mesh(meshes[0]);
 
-        glBindVertexArray(0);
     glUseProgram(0);
 
     // We usually have two buffers, the first is hidden and that's

src/math.h

@@ -1,11 +1,38 @@
 #pragma once
 
+#include <cstdint>
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 #include <glm/gtc/type_ptr.hpp>
 
+// using u8  = uint8_t;
+// using u16 = uint16_t;
+// using u32 = uint32_t;
+// using u64 = uint64_t;
+
+// using i8  = int8_t;
+// using i16 = int16_t;
+// using i32 = int32_t;
+// using i64 = int64_t;
+
+typedef char unsigned u8;
+typedef short unsigned u16;
+typedef int unsigned u32;
+typedef long long unsigned u64;
+
+typedef char s8;
+typedef short s16;
+typedef int s32;
+typedef long long s64;
+
+typedef s32 b32;
+
+typedef float f32;
+typedef double f64;
+
+#define array_count(Array) (sizeof(Array) / sizeof((Array)[0]))
+
 using Matrix4 = glm::mat4;
 using Vector3 = glm::vec3;
 
-const float RADIAN_FACTOR = 3.14159265f / 180.0f;
-
+const f32 RADIAN_FACTOR = 3.14159265f / 180.0f;

src/mesh.cpp

@@ -0,0 +1,70 @@
+#include "mesh.h"
+
+Mesh::Mesh() {
+  VAO = 0;
+  VBO = 0;
+  IBO = 0;
+  index_count = 0;
+}
+
+Mesh::~Mesh() {
+  clear_mesh(this);
+}
+
+void create_mesh(
+  Mesh *mesh,
+  f32 *vertices,
+  u32 *indices,
+  u32 vertices_count,
+  u32 indices_count
+) {
+  mesh->index_count = indices_count;
+
+  glGenVertexArrays(1, &mesh->VAO);
+  glBindVertexArray(mesh->VAO);
+
+  glGenBuffers(1, &mesh->IBO);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh->IBO);
+  glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices[0]) * indices_count, indices, GL_STATIC_DRAW);
+
+  glGenBuffers(1, &mesh->VBO);
+  glBindBuffer(GL_ARRAY_BUFFER, mesh->VBO);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices[0]) * vertices_count, vertices, GL_STATIC_DRAW);
+
+  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
+  glEnableVertexAttribArray(0);
+
+  // Unbinding
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+  glBindVertexArray(0);
+}
+
+void render_mesh(Mesh *mesh) {
+  glBindVertexArray(mesh->VAO);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh->IBO);
+  glDrawElements(GL_TRIANGLES, mesh->index_count, GL_UNSIGNED_INT, 0);
+
+  // Unbinding
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+  glBindVertexArray(0);
+}
+
+void clear_mesh(Mesh *mesh) {
+  if (mesh->IBO != 0) {
+    glDeleteBuffers(1, &mesh->IBO);
+    mesh->IBO = 0;
+  }
+
+  if (mesh->VBO != 0) {
+    glDeleteBuffers(1, &mesh->VBO);
+    mesh->VBO = 0;
+  }
+
+  if (mesh->VAO != 0) {
+    glDeleteVertexArrays(1, &mesh->VAO);
+    mesh->VAO = 0;
+  }
+
+  mesh->index_count = 0;
+}

src/mesh.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "math.h"
+#include <GL/glew.h>
+
+struct Mesh {
+  u32 VAO, VBO, IBO;
+  u32 index_count;
+
+  Mesh();
+  ~Mesh();
+};
+
+void create_mesh(Mesh *mesh, f32 *vertices, u32 *indices, u32 vertices_count, u32 indices_count);
+void render_mesh(Mesh *mesh);
+void clear_mesh(Mesh *mesh);
+

src/notes.txt

@@ -28,3 +28,9 @@ Creating a Shader program
 6. Link program (creates executables from shaders and links them together).
 7. Validate program (because things run on the GPU it's harder to debug).
 
+
+
+Projections: Coordinate systems
+- Local space: raw position of each vertex draw relative to origin.
+- World space: position in the word itself if camery is assumed to be positioned at the origin.
+

src/shader.cpp

@@ -1,66 +1,106 @@
-#include <stdio.h>
-#include <string.h>
 #include "shader.h"
 
-bool add_shader(GLuint *program, Shader *shader) {
-    shader->gl = glCreateShader(shader->type);
-    const GLchar *code[1];
-    code[0] = shader->raw_code;
+Shader::Shader() {
+  id = 0;
+  uniform_projection = 0;
+  uniform_model = 0;
+}
 
-    GLint code_length[1];
-    code_length[0] = strlen(shader->raw_code);
+Shader::~Shader() {
+  clear_shader(this);
+}
 
-    glShaderSource(shader->gl, 1, code, code_length);
-    glCompileShader(shader->gl);
+bool create_shader(Shader *shader, const char *vertex_shader_path, const char *fragment_shader_path) {
+  std::string vertex_shader_code = read_entire_file(vertex_shader_path);
+  std::string fragment_shader_code = read_entire_file(fragment_shader_path);
   
-    GLint result = 0;
-    GLchar errors[1024] = { 0 };
 
-    glGetShaderiv(shader->gl, GL_COMPILE_STATUS, &result);
-    if (!result) {
-        glGetShaderInfoLog(shader->gl, sizeof(errors), NULL, errors);
-        printf("Error compiling the %d shader->gl: '%s'\n", shader->type, errors);
+  shader->id = glCreateProgram();
+
+  if (!shader) {
+    printf("Error creating shader shader!\n");
     return false;
   }
 
-    glAttachShader(*program, shader->gl);
-    return true;
-}
+  {
+    bool success = add_shader(shader, vertex_shader_code.c_str(), VERTEX);
 
-bool compile_shaders(GLuint *program, GLuint *uniform_model, Shader *vertex_shader, Shader *fragment_shader) {
-    *program = glCreateProgram();
-
-    if (!program) {
-        printf("Error creating shader program!\n");
+    if (!success) {
+      printf("Error adding vertex shader");
       return false;
     }
+  }
 
-    add_shader(program, vertex_shader);
-    add_shader(program, fragment_shader);
+  {
+    bool success = add_shader(shader, fragment_shader_code.c_str(), FRAGMENT);
 
-    GLint result = 0;
-    GLchar errors[1024] = { 0 };
+    if (!success) {
+      printf("Error adding fragment shader");
+      return false;
+    }
+  }
 
-    glLinkProgram(*program);
-    glGetProgramiv(*program, GL_LINK_STATUS, &result);
+  s32 result = 0;
+  s8 errors[1024] = {0};
+
+  glLinkProgram(shader->id);
+  glGetProgramiv(shader->id, GL_LINK_STATUS, &result);
 
   if (!result) {
-        glGetProgramInfoLog(*program, sizeof(errors), NULL, errors);
-        printf("Error linking program: '%s'\n", errors);
+    glGetProgramInfoLog(shader->id, sizeof(errors), NULL, errors);
+    printf("Error linking shader: '%s'\n", errors);
     return false;
   }
 
-    glValidateProgram(*program);
-    glGetProgramiv(*program, GL_VALIDATE_STATUS, &result);
+  glValidateProgram(shader->id);
+  glGetProgramiv(shader->id, GL_VALIDATE_STATUS, &result);
 
   if (!result) {
-        glGetProgramInfoLog(*program, sizeof(errors), NULL, errors);
-        printf("Error validating program: '%s'\n", errors);
+    glGetProgramInfoLog(shader->id, sizeof(errors), NULL, errors);
+    printf("Error validating shader: '%s'\n", errors);
     return false;
   }
 
-    *uniform_model = glGetUniformLocation(*program, "model");
+  shader->uniform_projection = glGetUniformLocation(shader->id, "projection");
+  shader->uniform_model = glGetUniformLocation(shader->id, "model");
 
   return true;
 }
 
+bool add_shader(Shader *shader, const char *shader_code, Shader_Type shader_type) {
+  u32 _shader = glCreateShader(shader_type);
+
+  const char *code[1];
+  code[0] = shader_code;
+
+  int code_length[1];
+  code_length[0] = strlen(shader_code);
+
+  glShaderSource(_shader, 1, code, code_length);
+  glCompileShader(_shader);
+
+  int result = 0;
+  char errors[1024] = {0};
+
+  glGetShaderiv(_shader, GL_COMPILE_STATUS, &result);
+  if (!result) {
+    glGetShaderInfoLog(_shader, sizeof(errors), NULL, errors);
+    printf("Error compiling the %d shader->id: '%s'\n", shader_type, errors);
+    return false;
+  }
+
+  glAttachShader(shader->id, _shader);
+
+  return true;
+}
+
+void clear_shader(Shader *shader) {
+  if (shader->id != 0) {
+    glDeleteProgram(shader->id);
+    shader->id = 0;
+  }
+
+  shader->uniform_model = 0;
+  shader->uniform_projection = 0;
+}
+

src/shader.h

@@ -2,18 +2,23 @@
 
 #include <GL/glew.h>
 #include <GL/gl.h>
+#include "math.h"
+#include "file.h"
 
-enum Shader_Type : unsigned int {
+enum Shader_Type : u32 {
   VERTEX = GL_VERTEX_SHADER,
   FRAGMENT = GL_FRAGMENT_SHADER
 };
 
 struct Shader {
-  Shader_Type type;
-  const char *raw_code;
-  GLuint gl;
+  u32 id;
+  u32 uniform_projection;
+  u32 uniform_model;
+
+  Shader();
+  ~Shader();
 };
 
-bool add_shader(GLuint *program, Shader *shader, const char *raw_code);
-
-bool compile_shaders(GLuint *shader_program, GLuint *uniform_model, Shader *vertex_shader, Shader *fragment_shader);
+bool create_shader(Shader *shader, const char *vertex_shader_path, const char *fragment_shader_path);
+bool add_shader(Shader *shader, const char *shader_code, Shader_Type type);
+void clear_shader(Shader *shader);

src/window.cpp

@@ -1,11 +1,3 @@
-#include <stdio.h>
-#include <string.h>
-#include <GL/glew.h>
-#include <GLFW/glfw3.h>
-#include <cmath>
-#include <glm/glm.hpp>
-#include <glm/gtc/matrix_transform.hpp>
-#include <glm/gtc/type_ptr.hpp>
 #include "window.h"
 
 bool setup_window(Window *window) {
@@ -32,14 +24,14 @@ bool setup_window(Window *window) {
     const char *desc;
     int code = glfwGetError(&desc);
     printf("GLFW window creation failed!");
-        printf("GLFW error code: %d, description: %s\n", code, desc ? desc : "No description given");
+    printf("GLFW error code: %d, description: %s\n", code,
+           desc ? desc : "No description given");
     glfwTerminate();
     return false;
   }
 
   // Get Buffer size information
-    int buffer_width, buffer_height;
-    glfwGetFramebufferSize(window->gl_window, &buffer_width, &buffer_height);
+  glfwGetFramebufferSize(window->gl_window, &window->buffer_width, &window->buffer_height);
 
   // Set context for GLEW to use
   glfwMakeContextCurrent(window->gl_window);
@@ -59,9 +51,10 @@ bool setup_window(Window *window) {
     return false;
   }
 
+  glEnable(GL_DEPTH_TEST);
+
   // Setup viewport size
-    glViewport(0, 0, buffer_width, buffer_height);
+  glViewport(0, 0, window->buffer_width, window->buffer_height);
 
   return true;
 }
-

src/window.h

@@ -1,9 +1,16 @@
 #pragma once
 
+#include <GL/glew.h>
 #include <GLFW/glfw3.h>
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <stdio.h>
+#include <string.h>
+#include "math.h"
 
 struct Window {
-  GLint width = 800, height = 600;
+  u32 width = 800, height = 600;
+  s32 buffer_width, buffer_height;
   GLFWwindow *gl_window = nullptr;
 };