前言

在上一篇OpenGL 环境搭建基础上修改main.cpp文件，完成使用OpenGL图片绘制和移动效果。

代码

详细代码已做注释：

#include "GLShaderManager.h"
#include "GLTools.h"
#include <GLUT/GLUT.h>//着色管理器
GLShaderManager shaderManager;//批次容器
GLBatch quadsBatch;//矩形坐标长度
GLfloat blockSize = 0.1f;//顶点坐标
GLfloat vVerts[] = {-blockSize,-blockSize,0.0f,blockSize,-blockSize,0.0f,blockSize,blockSize,0.0f,-blockSize,blockSize,0.0f
};//窗口大小修改回调
void changeSize(int w, int h) {glViewport(0, 0, w, h);
}//区域渲染
void renderScene(void) {//清除一个缓存区glClear(GL_COLOR_BUFFER_BIT);GLfloat vBlue[] = {0.0,0.0,1.0,1.0f};//使用着色器渲染shaderManager.UseStockShader(GLT_SHADER_IDENTITY,vBlue);quadsBatch.Draw();//后台缓冲区渲染完毕后交给前台显示glutSwapBuffers();}//初始化
void setupRC() {glClearColor(0.5f, 0.5f, 0.5f, 0.5f);shaderManager.InitializeStockShaders();quadsBatch.Begin(GL_QUADS, 4);quadsBatch.CopyVertexData3f(vVerts);quadsBatch.End();
}//处理键盘控制图形移动
void specialKeys(int key, int x, int y) {GLfloat stepSize = 0.01f;GLfloat blockX = vVerts[0];GLfloat blockY = vVerts[10];if (key == GLUT_KEY_UP) {blockY += stepSize;}if (key == GLUT_KEY_DOWN) {blockY -= stepSize;}if (key == GLUT_KEY_LEFT) {blockX -= stepSize;}if (key == GLUT_KEY_RIGHT) {blockX += stepSize;}if (blockX < -1.0f) {blockX = -1.0f;}if (blockX > (1.0 - blockSize * 2)) {blockX = 1.0f - blockSize * 2;}if (blockY < -1.0f + blockSize * 2 ) {blockY = -1.0f + blockSize * 2;}if (blockY > 1.0f) {blockY = 1.0f;}//处理顶点vVerts[0] = blockX;vVerts[1] = blockY - blockSize*2;vVerts[3] = blockX + blockSize*2;vVerts[4] = blockY - blockSize*2;vVerts[6] = blockX + blockSize*2;vVerts[7] = blockY;vVerts[9] = blockX;vVerts[10] = blockY;quadsBatch.CopyVertexData3f(vVerts);glutPostRedisplay();
}int main(int argc, char *argv[]) {//设置工作目录gltSetWorkingDirectory(argv[0]);//初始化glut库glutInit(&argc, argv);//初始化一个双缓冲区，离屏区渲染，窗口区显示glutInitDisplayMode(GLUT_DOUBLE);glutInitWindowSize(600, 600);glutCreateWindow("dowZhange");//注册重塑函数glutReshapeFunc(changeSize);//注册显示函数glutDisplayFunc(renderScene);glutSpecialFunc(specialKeys);//用于检查OpenGL API对程序可用GLenum status = glewInit();if (GLEW_OK != status) {return 1;}setupRC();glutMainLoop();return 0;
}复制代码