注意:需要在配置好OpenGL的编程环境中运行下列代码,环境配置文章可参考:
OpenGL在Mac项目上的配置
下面的代码,直接放置在main.cpp文件中即可:
#include "GLTools.h" #include "GLFrustum.h" #include <GLUT/GLUT.h> GLShaderManager shaderManager; GLFrustum viewFrustum; GLBatch smallStarBatch; GLBatch mediumStarBatch; GLBatch largeStarBatch; GLBatch mountainRangeBatch; GLBatch moonBatch; #define SMALL_STARS 100 #define MEDIUM_STARS 40 #define LARGE_STARS 15 #define SCREEN_X 800 #define SCREEN_Y 720 // 点击菜单选项触发的回调方法 void ProcessMenu(int value) { switch (value) { case 1: // 开启抗锯齿处理,必须先开启颜色混合模式 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_BLEND); // 点抗锯齿 glEnable(GL_POINT_SMOOTH); /* GL_NICEST:效果最好 GL_FASTEST:效果最快 */ glHint(GL_POINT_SMOOTH_HINT, GL_NICEST); // 线抗锯齿 glEnable(GL_LINE_SMOOTH); glHint(GL_LINE_SMOOTH_HINT, GL_NICEST); // 多边形抗锯齿 glEnable(GL_POLYGON_SMOOTH); glHint(GL_POLYGON_SMOOTH_HINT, GL_NICEST); break; case 2: // 关闭抗锯齿处理 glDisable(GL_BLEND); glDisable(GL_POINT_SMOOTH); glDisable(GL_LINE_SMOOTH); glDisable(GL_POLYGON_SMOOTH); break; default: break; } // 触发渲染 glutPostRedisplay(); } // 渲染画面 void RenderScene(void) { // 清除缓存区 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // 设置着色器为单位白色 GLfloat vWhite[] = {1.0f, 1.0f, 1.0f, 1.0f}; shaderManager.UseStockShader(GLT_SHADER_FLAT, viewFrustum.GetProjectionMatrix(), vWhite); // 画小点 glPointSize(1.0f); smallStarBatch.Draw(); // 画大点 glPointSize(4.0f); mediumStarBatch.Draw(); // 画超大点 glPointSize(8.0f); largeStarBatch.Draw(); // 画月亮 moonBatch.Draw(); // 画山的轮廓 glLineWidth(3.5); mountainRangeBatch.Draw(); // 将在后台缓冲区进行渲染,然后在结束时交换到前台 glutSwapBuffers(); } // 初始化小点批次 void SetupSmallStarBatch() { M3DVector3f vVerts[SMALL_STARS]; for (int i = 0; i < SMALL_STARS; i++) { vVerts[i][0] = (GLfloat)(rand() % SCREEN_X); vVerts[i][1] = (GLfloat)(rand() % (SCREEN_Y -100)) + 100.0f; vVerts[i][2] = 0.0f; } smallStarBatch.Begin(GL_POINTS, SMALL_STARS); smallStarBatch.CopyVertexData3f(vVerts); smallStarBatch.End(); } // 初始化大点批次 void SetupMediumStarBatch() { M3DVector3f vVerts[MEDIUM_STARS]; for (int i = 0; i < MEDIUM_STARS; i++) { vVerts[i][0] = (GLfloat)(rand() % SCREEN_X); vVerts[i][1] = (GLfloat)(rand() % (SCREEN_Y -100)) + 100.0f; vVerts[i][2] = 0.0f; } mediumStarBatch.Begin(GL_POINTS, MEDIUM_STARS); mediumStarBatch.CopyVertexData3f(vVerts); mediumStarBatch.End(); } // 初始化超大点批次 void SetupLargeStarBatch() { M3DVector3f vVerts[LARGE_STARS]; for (int i = 0; i < LARGE_STARS; i++) { vVerts[i][0] = (GLfloat)(rand() % SCREEN_X); vVerts[i][1] = (GLfloat)(rand() % (SCREEN_Y -100)) + 100.0f; vVerts[i][2] = 0.0f; } largeStarBatch.Begin(GL_POINTS, LARGE_STARS); largeStarBatch.CopyVertexData3f(vVerts); largeStarBatch.End(); } // 初始化山轮廓批次 void SetupMountainRangeBatch() { M3DVector3f vMountains[12] = { 0.0f, 25.0f, 0.0f, 50.0f, 100.0f, 0.0f, 100.0f, 25.0f, 0.0f, 225.0f, 125.0f, 0.0f, 300.0f, 50.0f, 0.0f, 375.0f, 100.0f, 0.0f, 460.0f, 25.0f, 0.0f, 525.0f, 100.0f, 0.0f, 600.0f, 20.0f, 0.0f, 675.0f, 70.0f, 0.0f, 750.0f, 25.0f, 0.0f, 800.0f, 90.0f, 0.0f }; mountainRangeBatch.Begin(GL_LINE_STRIP, 12); mountainRangeBatch.CopyVertexData3f(vMountains); mountainRangeBatch.End(); } // 初始化月亮批次 void SetupMoonBatch() { GLfloat x = 700.0f; GLfloat y = 500.0f; GLfloat r = 50.0f; M3DVector3f vVerts[SMALL_STARS]; int nVerts = 0; vVerts[nVerts][0] = x; vVerts[nVerts][1] = y; vVerts[nVerts][2] = 0.0f; for (GLfloat angle = 0; angle < M3D_2PI; angle += 0.2f) { nVerts++; vVerts[nVerts][0] = x + float(cos(angle)) * r; vVerts[nVerts][1] = y + float(sin(angle)) * r; vVerts[nVerts][2] = 0.0f; } nVerts++; vVerts[nVerts][0] = x + r; vVerts[nVerts][1] = y; vVerts[nVerts][2] = 0.0f; moonBatch.Begin(GL_TRIANGLE_FAN, 34); moonBatch.CopyVertexData3f(vVerts); moonBatch.End(); } // 程序一次性初始化 void SetupRC() { // 设置背景色为黑色 glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // 初始化着色器管理者 shaderManager.InitializeStockShaders(); // 初始化各个图元批次 SetupSmallStarBatch(); SetupMediumStarBatch(); SetupLargeStarBatch(); SetupMountainRangeBatch(); SetupMoonBatch(); } // 窗口大小改变时接受新的宽度和高度 void ChangeSize(int w, int h) { glViewport(0, 0, w, h); // 正投影 viewFrustum.SetOrthographic(0.0f, SCREEN_X, 0.0f, SCREEN_Y, -1.0f, 1.0f); } // 程序入口 int main(int argc, char *argv[]) { // 设置当前工作目录,针对Mac OS X gltSetWorkingDirectory(argv[0]); // GLUT初始化 glutInit(&argc, argv); /* 初始化渲染模式,其中标志GLUT_DOUBLE、GLUT_RGBA、GLUT_DEPTH、GLUT_STENCILf分别指双缓冲窗口、RGBA颜色模式、深度测试、模板缓冲区 */ glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH); // 初始化窗口大小 glutInitWindowSize(800, 720); // 创建窗口 glutCreateWindow("Smoothing Out The Jaggies"); // 创建菜单并绑定回调函数,添加选项,确定右键触发 glutCreateMenu(ProcessMenu); glutAddMenuEntry("Antialiased Rendering", 1); glutAddMenuEntry("Normal Rendering", 2); glutAttachMenu(GLUT_RIGHT_BUTTON); // 注册回调函数 glutReshapeFunc(ChangeSize); glutDisplayFunc(RenderScene); // 确保驱动程序的初始化中没有出现任何问题 GLenum err = glewInit(); if (err != GLEW_OK) { fprintf(stderr, "glew error:%s\n", glewGetErrorString(err)); return 1; } // 初始化设置 SetupRC(); // 进入调用循环 glutMainLoop(); return 0; }
运行代码后的效果(普通,非抗锯齿模式):
抗锯齿模式的对比图: