buffers

inc/engine/buffers.hpp

@@ -0,0 +1,57 @@
+#ifndef BUFFERS_HPP
+#define BUFFERS_HPP
+#define GL_GLEXT_PROTOTYPES
+
+#include <SDL3/SDL_opengl.h>
+#include <cstddef>
+#include <memory>
+
+// Vertex Buffer Class
+class VertexBuffer {
+public:
+    VertexBuffer();
+    ~VertexBuffer();
+
+    void bind() const;
+    void setData(const void* data, GLsizeiptr size);
+    void setAttributePointer(GLuint index, std::size_t size, GLenum type, bool normalized, std::size_t stride, std::size_t pointer);
+
+private:
+    GLuint bufferID;
+};
+
+// Element Buffer Class
+class ElementBuffer {
+public:
+    ElementBuffer();
+    ~ElementBuffer();
+
+    void bind() const;
+    void setData(const void* data, GLsizeiptr size);
+    void draw() const;
+
+private:
+    GLuint bufferID;
+    std::size_t elementCount;
+    GLenum drawMode;
+};
+
+// Vertex Array Object Class
+class VertexArrayObject {
+public:
+    VertexArrayObject();
+    ~VertexArrayObject();
+
+    void bind() const;
+    void draw() const;
+    void bufferVertexData(const void* data, GLsizeiptr size);
+    void bufferElementData(const void* data, GLsizeiptr size);
+    void setAttributePointer(GLuint index, std::size_t size, GLenum type, bool normalized, std::size_t stride, std::size_t pointer);
+
+private:
+    GLuint arrayID;
+    std::unique_ptr<VertexBuffer> vertexBuffer;
+    std::unique_ptr<ElementBuffer> elementBuffer;
+};
+
+#endif

inc/engine/opengl.hpp

@@ -4,6 +4,8 @@
 // Includes
 #include <SDL3/SDL_opengl.h>
 #include "engine/sdl.hpp"
+#include "engine/buffers.hpp"
+#include "engine/shaders.hpp"
 
 // OpenGL Context Class
 class OpenGLContext {

shaders/triangle.vert

@@ -1,6 +1,7 @@
 #version 330 core
 
 layout(location = 0) in vec3 position; // Vertex position
+layout(location = 1) in vec3 inColor; // Vertex color
 out vec3 color; // Output color to the fragment shader
 
 uniform mat4 model;
@@ -9,5 +10,5 @@ uniform mat4 projection;
 
 void main() {
     gl_Position = projection * view * model * vec4(position, 1.0); // Apply transformation matrices
-    color = position + vec3(0.5); // Set the color based on the vertex position
+    color = inColor; // Set the color output
 }

src/engine/buffers.cpp

@@ -0,0 +1,103 @@
+#include "engine/buffers.hpp"
+
+// Vertex Buffer Constructor
+VertexBuffer::VertexBuffer() {
+    glGenBuffers(1, &bufferID);
+}
+
+// Vertex Buffer Destructor
+VertexBuffer::~VertexBuffer() {
+    glDeleteBuffers(1, &bufferID);
+}
+
+// Bind Vertex Buffer
+void VertexBuffer::bind() const {
+    glBindBuffer(GL_ARRAY_BUFFER, bufferID);
+}
+
+// Set Data for Vertex Buffer
+void VertexBuffer::setData(const void* data, GLsizeiptr size) {
+    bind();
+    glBufferData(GL_ARRAY_BUFFER, size, data, GL_STATIC_DRAW);
+}
+
+// Set Attribute Pointer for Vertex Buffer
+void VertexBuffer::setAttributePointer(GLuint index, std::size_t size, GLenum type, bool normalized, std::size_t stride, std::size_t pointer) {
+    bind();
+    glVertexAttribPointer(index, size, type, normalized ? GL_TRUE : GL_FALSE, stride, (void*)pointer);
+    glEnableVertexAttribArray(index);
+}
+
+// Element Buffer Constructor
+ElementBuffer::ElementBuffer(): elementCount(0), drawMode(GL_TRIANGLES) {
+    glGenBuffers(1, &bufferID);
+}
+
+// Element Buffer Destructor
+ElementBuffer::~ElementBuffer() {
+    glDeleteBuffers(1, &bufferID);
+}
+
+// Bind Element Buffer
+void ElementBuffer::bind() const {
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bufferID);
+}
+
+// Set Data for Element Buffer
+void ElementBuffer::setData(const void* data, GLsizeiptr size) {
+    bind();
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, size, data, GL_STATIC_DRAW);
+    elementCount = size / sizeof(GLuint); // Assuming GLuint indices
+}
+
+// Draw Elements using Element Buffer
+void ElementBuffer::draw() const {
+    bind();
+    glDrawElements(drawMode, static_cast<GLsizei>(elementCount), GL_UNSIGNED_INT, 0);
+}
+
+// Vertex Array Object Constructor
+VertexArrayObject::VertexArrayObject() {
+    glGenVertexArrays(1, &arrayID);
+    glBindVertexArray(arrayID);
+
+    // Initialize associated buffers
+    vertexBuffer = std::make_unique<VertexBuffer>();
+    elementBuffer = std::make_unique<ElementBuffer>();
+    vertexBuffer->bind();
+    elementBuffer->bind();
+}
+
+// Vertex Array Object Destructor
+VertexArrayObject::~VertexArrayObject() {
+    glDeleteVertexArrays(1, &arrayID);
+}
+
+// Bind Vertex Array Object
+void VertexArrayObject::bind() const {
+    glBindVertexArray(arrayID);
+}
+
+// Draw using Vertex Array Object
+void VertexArrayObject::draw() const {
+    bind();
+    elementBuffer->draw();
+}
+
+// Buffer Vertex Data
+void VertexArrayObject::bufferVertexData(const void* data, GLsizeiptr size) {
+    bind();
+    vertexBuffer->setData(data, size);
+}
+
+// Buffer Element Data
+void VertexArrayObject::bufferElementData(const void* data, GLsizeiptr size) {
+    bind();
+    elementBuffer->setData(data, size);
+}
+
+// Set Attribute Pointer
+void VertexArrayObject::setAttributePointer(GLuint index, std::size_t size, GLenum type, bool normalized, std::size_t stride, std::size_t pointer) {
+    bind();
+    vertexBuffer->setAttributePointer(index, size, type, normalized, stride, pointer);
+}

src/engine/shaders.cpp

@@ -1,4 +1,4 @@
-#include "engine/shader.hpp"
+#include "engine/shaders.hpp"
 #include <iostream>
 #include <fstream>
 #include <SDL3/SDL_log.h>

src/main.cpp

@@ -1,10 +1,10 @@
 #define GL_GLEXT_PROTOTYPES
 #include "engine/sdl.hpp"
 #include "engine/opengl.hpp"
-#include "engine/shader.hpp"
 
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>
+#include <iostream>
 
 int main(int argc, char* argv[]) {
     SDLWindow window("My SDL Application", 800, 600);
@@ -23,11 +23,12 @@ int main(int argc, char* argv[]) {
     Shader shader_program("shaders/triangle.vert", "shaders/triangle.frag");
 
     // test setup
+    // vertex, color
     float vertexData[] = {
-        0.5f,  0.5f, 0.0f,  // top right
+        0.5f,  0.5f, 0.0f, 1.0f, 0.0f, 0.0f, // top right
-        0.5f, -0.5f, 0.0f,  // bottom right
+        0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom right
-        -0.5f,  0.5f, 0.0f,  // top left
+        -0.5f,  0.5f, 0.0f, 0.0f, 1.0f, 0.0f, // top left
-        -0.5f, -0.5f, 0.0f,  // bottom left
+        -0.5f, -0.5f, 0.0f, 1.0f, 1.0f, 0.0f  // bottom left
     };
 
     unsigned int indexData[] = {
@@ -35,27 +36,13 @@ int main(int argc, char* argv[]) {
         1, 3, 2   // second triangle
     };
     
-    unsigned int VBO, VAO, EBO;
+    // glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
-    
-    glGenVertexArrays(1, &VAO);
-    glGenBuffers(1, &VBO);
-    glGenBuffers(1, &EBO);
-
-    glBindVertexArray(VAO);
-
-    glBindBuffer(GL_ARRAY_BUFFER, VBO);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertexData), vertexData, GL_STATIC_DRAW);
-
-    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
-    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indexData), indexData, GL_STATIC_DRAW);
-
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
-    glEnableVertexAttribArray(0);
-
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-    glBindVertexArray(0);
-    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 
+    VertexArrayObject VAO;
+    VAO.bufferVertexData(vertexData, sizeof(vertexData));
+    VAO.bufferElementData(indexData, sizeof(indexData));
+    VAO.setAttributePointer(0, 3, GL_FLOAT, false, 6 * sizeof(float), 0); // position
+    VAO.setAttributePointer(1, 3, GL_FLOAT, false, 6 * sizeof(float), 3 * sizeof(float)); // color
 
     window.setPosition(SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
     window.showWindow();
@@ -70,9 +57,7 @@ int main(int argc, char* argv[]) {
         shader_program.setMat4("projection", projectionMatrix);
         shader_program.setMat4("model", modelMatrix);
 
-        glBindVertexArray(VAO);
+        VAO.draw();
-        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
-        glBindVertexArray(0);
 
         glContext.swapBuffers();
     }