L系统 三维分形树。

#include <GL/glut.h> #include "LSystem.h" //L系统 GLint WindW = 800; GLint WindH = 600; GLfloat oldx, oldy;//鼠标移动因子 GLfloat scale = 1.0;//放大缩小 GLfloat xangle = 15.0f; GLfloat yangle = -15.0f;//旋转因子 GLuint texout; //纹理 GLuint texin; #define BMP_Header_Length 54 //图像数据在内存块中的偏移量 GLfloat Pi1 = 3.14159; Tree tree; LSystem lsrule(tree); int LoadGLTextures(char *Filename, GLuint *ttexture, int i)//ttexture[i]为用来绑定纹理数据的整数,可更改 { FILE *File; BITMAPINFOHEADER header; BYTE *texture;//texture长宽和像素RGBA texture[width][height][4] int width, height, m, j; unsigned char *image; File = fopen(Filename, "rb"); //读取BMP信息头，跳过14字节文件头 if (File) { fseek(File, 14, SEEK_SET); fread(&header, sizeof(BITMAPINFOHEADER), 1, File); } else return FALSE; //读取长宽 width = header.biWidth; height = header.biHeight; //为image分配像素空间，读取图片数据，为texture分配width*height*4的四位空间用来生成纹理 image = (unsigned char *)malloc(width*height * 3); fread(image, sizeof(unsigned char), width*height * 3, File);//唯一的不足之处在于将3字节像素读为一维字符串 texture = (BYTE *)malloc(width*height * 4);// 唯一的不足之处在于将4字节像素读为一维字符串 //以下代码将对texture重排列，一般来说为Blue Green Red Alpha格式(24位图格式),生成纹理使用BGRA模式 /****************************************修改模块,通过像素任意修改图片，示例:*************************************************************/ //本段代码将纯黑色像素点透明度(Alpha)设为100%,其余颜色设为0% for (m = 0; m<width; m++) { for (j = 0; j<height; j++) { //把颜色值写入 texture[m*width * 4 + j * 4] = image[m*width * 3 + j * 3]; texture[m*width * 4 + j * 4 + 1] = image[m*width * 3 + j * 3 + 1]; texture[m*width * 4 + j * 4 + 2] = image[m*width * 3 + j * 3 + 2]; //设置alpha值,假设黑色为透明色 if (texture[m*width * 4 + j * 4] >= 200 && texture[m*width * 4 + j * 4 + 1] >= 200 && texture[m*width * 4 + j * 4 + 2] >= 200) { texture[m*width * 4 + j * 4 + 3] = 0; //透明，alpha=0 } else texture[m*width * 4 + j * 4 + 3] = 255; //不透明，alpha=255 } } //ttexture[i]为绑定纹理的整数 //下面生成纹理以及纹理处理 glGenTextures(1, &ttexture[i]); glBindTexture(GL_TEXTURE_2D, ttexture[i]); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexImage2D(GL_TEXTURE_2D, 0, 4, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, texture); gluBuild2DMipmaps(GL_TEXTURE_2D, 4, width, height, GL_BGRA_EXT, GL_UNSIGNED_BYTE, texture); glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); glAlphaFunc(GL_GREATER, 0.5);//使Alpha值生效 //纹理生成完毕,下面释放空间 free(texture); free(image); // 释放图像数据 return TRUE; // 返回 Status } int power_of_two(int n) { if (n <= 0) return 0; return (n & (n - 1)) == 0; } //读取纹理 GLuint load_texture(const char* file_name) { GLint width, height, total_bytes; GLubyte* pixels = 0; GLuint last_texture_ID = 0, texture_ID = 0; // 打开文件，如果失败，返回 FILE* pFile = fopen(file_name, "rb"); if (pFile == 0) return 0; // 读取文件中图象的宽度和高度 fseek(pFile, 0x0012, SEEK_SET); fread(&width, 4, 1, pFile); fread(&height, 4, 1, pFile); fseek(pFile, BMP_Header_Length, SEEK_SET); // 计算每行像素所占字节数，并根据此数据计算总像素字节数 { GLint line_bytes = width * 3; while (line_bytes % 4 != 0) ++line_bytes; total_bytes = line_bytes * height; } // 根据总像素字节数分配内存 pixels = (GLubyte*)malloc(total_bytes); if (pixels == 0) { fclose(pFile); return 0; } // 读取像素数据 if (fread(pixels, total_bytes, 1, pFile) <= 0) { free(pixels); fclose(pFile); return 0; } // 对就旧版本的兼容，如果图象的宽度和高度不是的整数次方，则需要进行缩放 // 若图像宽高超过了OpenGL规定的最大值，也缩放 { GLint max; glGetIntegerv(GL_MAX_TEXTURE_SIZE, &max); if (!power_of_two(width) || !power_of_two(height) || width > max || height > max) { const GLint new_width = 256; const GLint new_height = 256; // 规定缩放后新的大小为边长的正方形 GLint new_line_bytes, new_total_bytes; GLubyte* new_pixels = 0; // 计算每行需要的字节数和总字节数 new_line_bytes = new_width * 3; while (new_line_bytes % 4 != 0) ++new_line_bytes; new_total_bytes = new_line_bytes * new_height; // 分配内存 new_pixels = (GLubyte*)malloc(new_total_bytes); if (new_pixels == 0) { free(pixels); fclose(pFile); return 0; } // 进行像素缩放 gluScaleImage(GL_RGB, width, height, GL_UNSIGNED_BYTE, pixels, new_width, new_height, GL_UNSIGNED_BYTE, new_pixels); // 释放原来的像素数据，把pixels指向新的像素数据，并重新设置width和height free(pixels); pixels = new_pixels; width = new_width; height = new_height; } } // 分配一个新的纹理编号 glGenTextures(1, &texture_ID); if (texture_ID == 0) { free(pixels); fclose(pFile); return 0; } // 绑定新的纹理，载入纹理并设置纹理参数 // 在绑定前，先获得原来绑定的纹理编号，以便在最后进行恢复 GLint lastTextureID = last_texture_ID; glGetIntegerv(GL_TEXTURE_BINDING_2D, &lastTextureID); glBindTexture(GL_TEXTURE_2D, texture_ID); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_BGR_EXT, GL_UNSIGNED_BYTE, pixels); glBindTexture(GL_TEXTURE_2D, lastTextureID); //恢复之前的纹理绑定 free(pixels); return texture_ID; } void init() { //glClearColor(0.0, 0.0, 1.0, 0.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-25.0, 25.0, -25.0, 25.0, -25.0, 25.0); glMatrixMode(GL_MODELVIEW); glEnable(GL_DEPTH_TEST); glEnable(GL_TEXTURE_2D); // 启用纹理 //使alpha值生效 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_BLEND); // lsrule.initGrammar();//将文法迭代好 lsrule.generateFractal();//把树的树枝等先算好 //cout << lsrule.grammar.getRule() << endl;//成功迭代好 } //以yuandian两端点，r为半径 void drawcone(double r,double h) { glBindTexture(GL_TEXTURE_2D, texin); for (int i = 0; i <360; i += 50) { //在原点画了一个圆柱 float temp = i * Pi1 / 180; float temp1 = (i + 50)*Pi1 / 180; glBegin(GL_QUADS); glTexCoord2f((temp*r*tree.trunk.radius_shrink)/(2 * Pi1), 0.0f); glVertex3f(r*cos(temp)*tree.trunk.radius_shrink, 0, r*sin(temp)*tree.trunk.radius_shrink); glTexCoord2f((temp*r)/(2*Pi1), 1.0f); glVertex3f(r*cos(temp), h, r*sin(temp)); //竖着2倍 横着1/2 glTexCoord2f((temp1*r)/(2 * Pi1), 1.0f); glVertex3f(r*cos(temp1), h, r*sin(temp1)); glTexCoord2f((temp1*r*tree.trunk.radius_shrink) / (2 * Pi1), 0.0f); glVertex3f(r*cos(temp1)*tree.trunk.radius_shrink, 0.0f, r*sin(temp1)*tree.trunk.radius_shrink); glEnd(); } } void DrawChannel(Node A, Node B, double r) { // 起始线段：以(0,1,0)为起点,它的长度(distance)通过目标线段计算, // 终点坐标为(0,1-distance,0) // 目标线段：以(x1,y1,z1)为起点，以(x2,y2,z2)为终点 // 计算目标向量 GLfloat dx = B.x - A.x; GLfloat dy = B.y - A.y; GLfloat dz = B.z - A.z; // 算出目标向量模(即AB长度) GLfloat distance = sqrt(dx*dx + dy * dy + dz * dz); // 计算平移量 GLfloat px = A.x; GLfloa