130 lines
4.2 KiB
C++
130 lines
4.2 KiB
C++
#include <iostream>
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#include <SDL2/SDL.h>
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#include <GL/glew.h>
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#include <glm/glm.hpp>
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#include <fstream>
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#include <chrono>
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#include <string>
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#include <map>
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#include "shader.hpp"
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void GLAPIENTRY MessageCallback(GLenum source,
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GLenum type,
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GLuint id,
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GLenum severity,
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GLsizei length,
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const GLchar* message,
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const void* userParam) {
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fprintf(stderr, "GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
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(type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : "" ),
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type, severity, message);
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}
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class Game {
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public:
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SDL_Window* window = nullptr;
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SDL_GLContext glContext = nullptr;
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bool isWindowClosed = true;
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};
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int main(int argc, char** argv) {
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Game* game = new Game();
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SDL_Init(SDL_INIT_EVERYTHING);
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SDL_GL_SetSwapInterval(0);
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SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
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SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
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SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
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SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
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SDL_GL_SetAttribute(SDL_GL_BUFFER_SIZE, 32);
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SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
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game->window = SDL_CreateWindow("GL CUBE",
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SDL_WINDOWPOS_CENTERED,
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SDL_WINDOWPOS_CENTERED,
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400, 400,
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SDL_WINDOW_OPENGL);
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game->glContext = SDL_GL_CreateContext(game->window);
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GLenum GLEWStatus = glewInit();
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if (GLEWStatus != GLEW_OK) {
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std::cerr << "FAILED TO INITALIZE GLEW" << std::endl;
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return 0;
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}
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// SDL_WarpMouseInWindow(m_window, width / 2, height / 2);
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// SDL_SetRelativeMouseMode(SDL_TRUE);
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game->isWindowClosed = false;
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// Set GL error handling callback
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// glEnable(GL_DEBUG_OUTPUT);
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glDebugMessageCallback(MessageCallback, 0);
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// Set GL clear colour (light blue)
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glClearColor(0.1f, 0.45f, 0.9f, 1.0f);
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// GL Screen coordinates of a 2D triangle followed by the colour
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GLint numOfVerticies = 15;
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float vertices[] = {
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0.0f, 0.5f, 1.0f, 0.0f, 0.0f, // Vertex 1: (X, Y, R, G, B)
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0.5f, -0.5f, 0.0f, 1.0f, 0.0f, // Vertex 2: (X, Y, R, G, B)
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-0.5f, -0.5f, 0.0f, 0.0f, 1.0f // Vertex 3: (X, Y, R, G, B)
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};
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// Generate a vertex array object
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GLuint vao;
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glGenVertexArrays(1, &vao);
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// Bind array to GPU
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glBindVertexArray(vao);
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// Generate a vertex buffer object
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GLuint vbo;
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glGenBuffers(1, &vbo);
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// Binding buffer to GPU
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glBindBuffer(GL_ARRAY_BUFFER, vbo);
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// Copy vertex data to the vertex buffer already on the GPU
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glBufferData(GL_ARRAY_BUFFER, sizeof(vertices[0]) * numOfVerticies, vertices, GL_STATIC_DRAW);
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// Load, compile, apply and link shader programs
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Shader simpleShader;
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simpleShader.load("./shaders/simple").attatch().link().use();
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GLint posAttrib = glGetAttribLocation(simpleShader.getProgram(), "position");
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glEnableVertexAttribArray(posAttrib);
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glVertexAttribPointer(posAttrib, 2, GL_FLOAT, GL_FALSE,
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5*sizeof(float), 0);
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GLint colAttrib = glGetAttribLocation(simpleShader.getProgram(), "colour");
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glEnableVertexAttribArray(colAttrib);
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glVertexAttribPointer(colAttrib, 3, GL_FLOAT, GL_FALSE,
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5*sizeof(float), (void*)(2*sizeof(float)));
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GLint triangleUniColour = glGetUniformLocation(simpleShader.getProgram(), "triangleColour");
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glUniform3f(triangleUniColour, 0.2f, 0.8f, 0.3f);
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SDL_Event event;
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while (!game->isWindowClosed) {
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// Input handling
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while (SDL_PollEvent(&event) != 0)
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if (event.key.keysym.sym == SDLK_ESCAPE || event.type == SDL_QUIT)
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game->isWindowClosed = true;
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// Clear the screen
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glClear(GL_COLOR_BUFFER_BIT);
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// Draw a triangle from the 3 vertices
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glDrawArrays(GL_TRIANGLES, 0, 3);
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// Swap buffers
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SDL_GL_SwapWindow(game->window);
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}
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game->isWindowClosed = true;
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SDL_GL_DeleteContext(game->glContext);
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SDL_DestroyWindow(game->window);
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SDL_Quit();
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return 0;
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}
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