标签:isa iostream const mouse spl amp sdl public ==
经过前面几个系列的洗礼,对SDL及OPENGL有了很粗浅的认识
这次我们要升级了,钟爱的Sprite的闪现,先做个没有Shader的Spite,什么?
还有Shader?Shader是神马东东,别急,下一系列就会出现Shader
Sprite.h
1 #pragma once 2 #include <gl/glew.h> 3 4 class Sprite 5 { 6 public: 7 Sprite(); 8 ~Sprite(); 9 10 void init(float x, float y, float width, float height); 11 void draw(); 12 13 private: 14 float m_X; 15 float m_Y; 16 float m_Width; 17 float m_Height; 18 19 GLuint m_vboID; 20 };
Sprite.cpp
1 #include "Sprite.h" 2 3 4 Sprite::Sprite() :m_X(0.0f), m_Y(0.0f), m_Width(0.0f), m_Height(0.0f), m_vboID(0) 5 { 6 } 7 8 9 Sprite::~Sprite() 10 { 11 if (m_vboID) 12 { 13 glDeleteBuffers(1, &m_vboID); 14 } 15 } 16 17 void Sprite::init(float x, float y, float width, float height) 18 { 19 m_X = x; 20 m_Y = y; 21 m_Width = width; 22 m_Height = height; 23 24 if (0 == m_vboID) 25 { 26 glGenBuffers(1, &m_vboID); 27 } 28 29 //Hard code, vertex num: 6, xy:2 30 31 // v2 v1 32 // 33 // 34 // v3 35 float vertexData[6 * 2]; 36 //First Triangle 37 vertexData[0] = x + width; 38 vertexData[1] = y + height; 39 40 vertexData[2] = x; 41 vertexData[3] = y + height; 42 43 vertexData[4] = x; 44 vertexData[5] = y; 45 46 //Second Triangle 47 vertexData[6] = x; 48 vertexData[7] = y; 49 50 vertexData[8] = x + width; 51 vertexData[9] = y; 52 53 vertexData[10] = x + width; 54 vertexData[11] = y + width; 55 56 57 glBindBuffer(GL_ARRAY_BUFFER, m_vboID); 58 glBufferData(GL_ARRAY_BUFFER, sizeof(vertexData), vertexData, GL_STATIC_DRAW); 59 60 glBindBuffer(GL_ARRAY_BUFFER, 0); 61 } 62 63 void Sprite::draw() 64 { 65 glBindBuffer(GL_ARRAY_BUFFER, m_vboID); 66 67 glEnableVertexAttribArray(0); 68 69 glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0); 70 glDrawArrays(GL_TRIANGLES, 0, 6); 71 72 glDisableVertexAttribArray(0); 73 74 glBindBuffer(GL_ARRAY_BUFFER, 0); 75 }
MainGame.h
1 #pragma once 2 #include <SDL/SDL.h> 3 #include <GL/glew.h> 4 #include "Sprite.h" 5 6 enum class GameState{PLAY, EXIT}; 7 8 class MainGame 9 { 10 public: 11 MainGame(); 12 ~MainGame(); 13 14 void run(); 15 16 17 private: 18 void initSystems(); 19 void gameLoop(); 20 void processInput(); 21 void drawGame(); 22 23 SDL_Window* m_pWindow; 24 int m_nScreenWidth; 25 int m_nScreenHeight; 26 GameState m_gameState; 27 Sprite m_sprite; 28 };
MainGame.cpp
1 #include "MainGame.h" 2 #include <iostream> 3 #include <string> 4 void faterError(const std::string& errorString) 5 { 6 std::cout << errorString << std::endl; 7 std::cout << "Enter any key to quit..."; 8 std::cin.get(); 9 SDL_Quit(); 10 } 11 12 MainGame::MainGame() :m_pWindow(nullptr), m_nScreenWidth(1024), m_nScreenHeight(768), m_gameState(GameState::PLAY) 13 { 14 15 } 16 17 18 MainGame::~MainGame() 19 { 20 } 21 22 void MainGame::run() 23 { 24 initSystems(); 25 m_sprite.init(-1.0f, -1.0f, 1.0f, 1.0f); 26 gameLoop(); 27 } 28 29 void MainGame::initSystems() 30 { 31 //Initialize SDL 32 SDL_Init(SDL_INIT_EVERYTHING); 33 34 //Open an SDL Window 35 m_pWindow = SDL_CreateWindow("GraphicToturial", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, m_nScreenWidth, m_nScreenHeight, SDL_WINDOW_OPENGL); 36 if (nullptr == m_pWindow) 37 { 38 faterError("SDL Window could not be created!"); 39 } 40 41 //Set up our OpenGL Context 42 SDL_GLContext glContext = SDL_GL_CreateContext(m_pWindow); 43 if (nullptr == glContext) 44 { 45 faterError("SDL_GL context could not be created!"); 46 } 47 48 //Set up glew (optional but recommend) 49 glewExperimental = true; 50 GLenum result = glewInit(); 51 if (GLEW_OK != result) 52 { 53 faterError("Could not initialize glew!"); 54 } 55 56 //Tell SDL that we want a double buffered window so we dont get 57 //any flickering 58 SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1); 59 60 glClearColor(0, 0, 1, 1); 61 } 62 63 void MainGame::gameLoop() 64 { 65 while (m_gameState != GameState::EXIT) 66 { 67 processInput(); 68 drawGame(); 69 } 70 } 71 72 void MainGame::processInput() 73 { 74 SDL_Event evnt; 75 while (SDL_PollEvent(&evnt)) 76 { 77 switch (evnt.type) 78 { 79 case SDL_QUIT: 80 m_gameState = GameState::EXIT; 81 break; 82 case SDL_MOUSEMOTION: 83 std::cout << evnt.motion.x << " " << evnt.motion.y << std::endl; 84 break; 85 } 86 } 87 } 88 89 void MainGame::drawGame() 90 { 91 glClearDepth(1.0); 92 //Clear the color and depth buffer 93 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 94 95 //注意点1 96 //Tell OpenGL we want to use color. (only needed for immediate mode) 97 //glEnableClientState(GL_COLOR_ARRAY); 98 99 m_sprite.draw(); 100 101 //Swap our buffer and draw everything to the screen! 102 SDL_GL_SwapWindow(m_pWindow); 103 }
***注意点:
当使用Modern OpenGL时,不能有glEnableClientState(GL_COLOR_ARRAY);否则就会Booooo!!!!
标签:isa iostream const mouse spl amp sdl public ==
原文地址:https://www.cnblogs.com/unicornsir/p/12718952.html