opengl天空盒的效果源代码

//CTexture类在第8章， //CSkyBox在第24章， //那个GL_Application可以忽略，直接在主函数中生成dos窗口运行， #include <GL/glut.h> #include <GLTOOLS.H> #include <GL/OpenGLSB.h> #include <stdlib.h> #include <math.h> #define SNOWFLAKE_VX 0.0f #define SNOWFLAKE_VY -3.0f #define SNOWFLAKE_VZ 0.0f #define V_CHANGEX 0.2f #define V_CHANGEY 0.5f #define V_CHANGEZ 0.2f #define FRAND (((float)rand()-(float)rand())/RAND_MAX) #define SNOWFLAKE_SIZE 0.02f #define SNOWFLAKES_PER_SEC 2000 #define NUM_TEXTURES 3 GLuint textureObjects[NUM_TEXTURES]; struct SnowFlake { float x, y, z; //当前位置 float pre_x, pre_y, pre_z; //上次位置 float v_x, v_y, v_z; //速度 float a_x, a_y, a_z; //加速度 float lifetime; //生命值 float size; //尺寸大小 float sizeDelta; //尺寸变化量 float red, green, blue; //颜色 }; struct SnowSystem { SnowFlake* snowList; //雪花链表 int maxSnow; //雪花总数目 int numSnow; //雪花当前数目 float origin_x, origin_y, origin_z; //系统中心 float height, width, depth; float accumulatedTime; //消逝时间 }S_system; const char *szCubeFaces[6] = {"pos_x.tga", "neg_x.tga", "pos_y.tga", "neg_y.tga", "pos_z.tga", "neg_z.tga" }; GLenum cube[6] = { GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z}; void CreateSystem(int m_snow, float x, float y, float z, float height, float width, float depth) { S_system.maxSnow = m_snow; S_system.origin_x = x; S_system.origin_y = y; S_system.origin_z = z; S_system.height = height; S_system.width = width; S_system.depth = depth; S_system.snowList = NULL; } void InitSystem() { if(S_system.snowList) { delete[] S_system.snowList; S_system.snowList = NULL; } S_system.snowList = new SnowFlake[S_system.maxSnow]; S_system.numSnow = 0; S_system.accumulatedTime = 0.0f; } void InitSnowFlake(int index) { //设置雪花位置 S_system.snowList[index].y = S_system.height; S_system.snowList[index].x = S_system.origin_x + FRAND * S_system.width; S_system.snowList[index].z = S_system.origin_z + FRAND * S_system.depth; //设置雪花大小 S_system.snowList[index].size = SNOWFLAKE_SIZE; //设置雪花随机速度 S_system.snowList[index].v_x = SNOWFLAKE_VX + FRAND * V_CHANGEX; S_system.snowList[index].v_y = SNOWFLAKE_VY + FRAND * V_CHANGEY; S_system.snowList[index].v_z = SNOWFLAKE_VZ + FRAND * V_CHANGEZ; } int Emit(int num) { while(num && (S_system.numSnow < S_system.maxSnow)) { InitSnowFlake(S_system.numSnow ++); -- num; } return num; } void UpdateSystem(float elapsedTime) { for(int i = 0; i < S_system.numSnow; ) { //更新粒子位置 S_system.snowList[i].x = S_system.snowList[i].x + S_system.snowList[i].v_x * elapsedTime; S_system.snowList[i].y = S_system.snowList[i].y + S_system.snowList[i].v_y * elapsedTime; S_system.snowList[i].z = S_system.snowList[i].x + S_system.snowList[i].v_z * elapsedTime; //检测已消逝粒子 if(S_system.snowList[i].y <= S_system.origin_y) { //移动最后粒子到当前位置 S_system.snowList[i] = S_system.snowList[--S_system.numSnow]; } else ++ i; } //存储消逝时间 S_system.accumulatedTime += elapsedTime; //计算新粒子数目 int newSnowFlakes = SNOWFLAKES_PER_SEC * S_system.accumulatedTime; //保存时间 S_system.accumulatedTime -= 1.0f/(float)SNOWFLAKES_PER_SEC * newSnowFlakes; Emit(newSnowFlakes); } void SetupRC() { GLbyte *pBytes; GLint iWidth, iHeight, iComponents; GLenum eFormat; int i; // Cull backs of polygons glCullFace(GL_BACK); glFrontFace(GL_CCW); glEnable(GL_CULL_FACE); glEnable(GL_DEPTH_TEST); // Set up texture maps glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE); // Load Cube Map images for(i = 0; i < 6; i++) { // Load this texture map glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_GENERATE_MIPMAP, GL_TRUE); pBytes = gltLoadTGA(szCubeFaces[i], &iWidth, &iHeight, &iComponents, &eFormat); glTexImage2D(cube[i], 0, iComponents, iWidth, iHeight, 0, eFormat, GL_UNSIGNED_BYTE, pBytes); free(pBytes); } glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP); glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP); glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP); // Enable cube mapping, and set texture environment to decal glEnable(GL_TEXTURE_CUBE_MAP); glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); } void ShutdownRC(void) { // Delete the textures glDeleteTextures(NUM_TEXTURES, textureObjects); } void DrawSkyBox() { GLfloat fExtent = 15.0f; glBegin(GL_QUADS); //Negative X glTexCoord3f(-1.0f, -1.0f, 1.0f); glVertex3f(-fExtent, -fExtent, fExtent); glTexCoord3f(-1.0f, -1.0f, -1.0f); glVertex3f(-fExtent, -fExtent, -fExtent); glTexCoord3f(-1.0f, 1.0f, -1.0f); glVertex3f(-fExtent, fExtent, -fExtent); glTexCoord3f(-1.0f, 1.0f, 1.0f); glVertex3f(-fExtent, fExtent, fExtent); //Postive X glTexCoord3f(1.0f, -1.0f, -1.0f); glVertex3f(fExtent, -fExtent, -fExtent); glTexCoord3f(1.0f, -1.0f, 1.0f); glVertex3f(fExtent, -fExtent, fExtent); glTexCoord3f(1.0f, 1.0f, 1.0f); glVertex3f(fExtent, fExtent, fExtent); glTexCoord3f(1.0f, 1.0f, -1.0f); glVertex3f(fExtent, fExtent, -fExtent); // Negative Z glTexCoord3f(-1.0f, -1.0f, -1.0f); glVertex3f(-fExtent, -fExtent, -fExtent); glTexCoord3f(1.0f, -1.0f, -1.0f); glVertex3f(fExtent, -fExtent, -fExtent); glTexCoord3f(1.0f, 1.0f, -1.0f); glVertex3f(fExtent, fExtent, -fExtent); glTexCoord3f(-1.0f, 1.0f, -1.0f); glVertex3f(-fExtent, fExtent, -fExtent); // Positive Z glTexCoord3f(1.0f, -1.0f, 1.0f); glVertex3f(fExtent, -fExtent, fExtent); glTexCoord3f(-1.0f, -1.0f, 1.0f); glVertex3f(-fExtent, -fExtent, fExtent); glTexCoord3f(-1.0f, 1.0f, 1.0f); glVertex3f(-fExtent, fExtent, fExtent); glTexCoord3f(1.0f, 1.0f, 1.0f); glVertex3f(fExtent, fExtent, fExtent); // Positive Y glTexCoord3f(-1.0f, 1.0f, 1.0f); glVertex3f(-fExtent, fExtent, fExtent); glTexCoord3f(-1.0f, 1.0f, -1.0f); glVertex3f(-fExtent, fExtent, -fExtent); glTexCoord3f(1.0f, 1.0f, -1.0f); glVertex3f(fExtent, fExtent, -fExtent); glTexCoord3f(1.0f, 1.0f, 1.0f); glVertex3f(fExtent, fExtent, fExtent); // Negative Y glTexCoord3f(-1.0f, -1.0f, -1.0f); glVertex3f(-fExtent, -fExtent, -fExtent); glTexCoord3f(-1.0f, -1.0f, 1.0f); glVertex3f(-fExtent, -fExtent, fExtent); glTexCoord3f(1.0f, -1.0f, 1.0f); glVertex3f(fExtent, -fExtent, fExtent); glTexCoord3f(1.0f, -1.0f, -1.0f); glVertex3f(fExtent, -fExtent, -fExtent); glEnd(); } void RenderScene() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glPushMatrix(); glDisable(GL_TEXTURE_GEN_S); glDisable(GL_TEXTURE_GEN_T); glDisable(GL_TEXTURE_GEN_R); DrawSkyBox(); glPopMatrix(); glutSwapBuffers(); } void ChangeSize(int