raycasting_tutorial.zip_Cg C语言‘’_GPU_cg ray casting sln_cg语言_ray

// -------------------------------------------------------------------------- // GPU raycasting tutorial // Made by Peter Trier jan 2007 // // This file contains all the elements nessesary to implement a simple // GPU volume raycaster. // Notice this implementation requires a shader model 3.0 gfxcard // -------------------------------------------------------------------------- #include <windows.h> #include <GL/glew.h> #include <Cg/cg.h> #include <Cg/cgGL.h> #include <GL/gl.h> #include <GL/glut.h> #include <iostream> #include <fstream> #include <sstream> #include <vector> #include <cmath> #include <ctime> #include <cassert> #include "Vector3.h" #define MAX_KEYS 256 #define WINDOW_SIZE 800 #define VOLUME_TEX_SIZE 128 using namespace std; // Globals ------------------------------------------------------------------ bool gKeys[MAX_KEYS]; bool toggle_visuals = true; CGcontext context; CGprofile vertexProfile, fragmentProfile; CGparameter param1,param2; GLuint renderbuffer; GLuint framebuffer; CGprogram vertex_main,fragment_main; // the raycasting shader programs GLuint volume_texture; // the volume texture GLuint backface_buffer; // the FBO buffers GLuint final_image; float stepsize = 1.0/50.0; /// Implementation ---------------------------------------- void cgErrorCallback() { CGerror lastError = cgGetError(); if(lastError) { cout << cgGetErrorString(lastError) << endl; if(context != NULL) cout << cgGetLastListing(context) << endl; exit(0); } } // Sets a uniform texture parameter void set_tex_param(char* par, GLuint tex,const CGprogram &program,CGparameter param) { param = cgGetNamedParameter(program, par); cgGLSetTextureParameter(param, tex); cgGLEnableTextureParameter(param); } // load_vertex_program: loading a vertex program void load_vertex_program(CGprogram &v_program,char *shader_path, char *program_name) { assert(cgIsContext(context)); v_program = cgCreateProgramFromFile(context, CG_SOURCE,shader_path, vertexProfile,program_name, NULL); if (!cgIsProgramCompiled(v_program)) cgCompileProgram(v_program); cgGLEnableProfile(vertexProfile); cgGLLoadProgram(v_program); cgGLDisableProfile(vertexProfile); } // load_fragment_program: loading a fragment program void load_fragment_program(CGprogram &f_program,char *shader_path, char *program_name) { assert(cgIsContext(context)); f_program = cgCreateProgramFromFile(context, CG_SOURCE, shader_path, fragmentProfile,program_name, NULL); if (!cgIsProgramCompiled(f_program)) cgCompileProgram(f_program); cgGLEnableProfile(fragmentProfile); cgGLLoadProgram(f_program); cgGLDisableProfile(fragmentProfile); } void enable_renderbuffers() { glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, framebuffer); glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, renderbuffer); } void disable_renderbuffers() { glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); } void vertex(float x, float y, float z) { glColor3f(x,y,z); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, x, y, z); glVertex3f(x,y,z); } // this method is used to draw the front and backside of the volume void drawQuads(float x, float y, float z) { glBegin(GL_QUADS); /* Back side */ glNormal3f(0.0, 0.0, -1.0); vertex(0.0, 0.0, 0.0); vertex(0.0, y, 0.0); vertex(x, y, 0.0); vertex(x, 0.0, 0.0); /* Front side */ glNormal3f(0.0, 0.0, 1.0); vertex(0.0, 0.0, z); vertex(x, 0.0, z); vertex(x, y, z); vertex(0.0, y, z); /* Top side */ glNormal3f(0.0, 1.0, 0.0); vertex(0.0, y, 0.0); vertex(0.0, y, z); vertex(x, y, z); vertex(x, y, 0.0); /* Bottom side */ glNormal3f(0.0, -1.0, 0.0); vertex(0.0, 0.0, 0.0); vertex(x, 0.0, 0.0); vertex(x, 0.0, z); vertex(0.0, 0.0, z); /* Left side */ glNormal3f(-1.0, 0.0, 0.0); vertex(0.0, 0.0, 0.0); vertex(0.0, 0.0, z); vertex(0.0, y, z); vertex(0.0, y, 0.0); /* Right side */ glNormal3f(1.0, 0.0, 0.0); vertex(x, 0.0, 0.0); vertex(x, y, 0.0); vertex(x, y, z); vertex(x, 0.0, z); glEnd(); } // create a test volume texture, here you could load your own volume void create_volumetexture() { int size = VOLUME_TEX_SIZE*VOLUME_TEX_SIZE*VOLUME_TEX_SIZE* 4; GLubyte *data = new GLubyte[size]; for(int x = 0; x < VOLUME_TEX_SIZE; x++) {for(int y = 0; y < VOLUME_TEX_SIZE; y++) {for(int z = 0; z < VOLUME_TEX_SIZE; z++) { data[(x*4) + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = z%250; data[(x*4)+1 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = y%250; data[(x*4)+2 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 250; data[(x*4)+3 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 230; Vector3 p = Vector3(x,y,z)- Vector3(VOLUME_TEX_SIZE-20,VOLUME_TEX_SIZE-30,VOLUME_TEX_SIZE-30); bool test = (p.length() < 42); if(test) data[(x*4)+3 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 0; p = Vector3(x,y,z)- Vector3(VOLUME_TEX_SIZE/2,VOLUME_TEX_SIZE/2,VOLUME_TEX_SIZE/2); test = (p.length() < 24); if(test) data[(x*4)+3 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 0; if(x > 20 && x < 40 && y > 0 && y < VOLUME_TEX_SIZE && z > 10 && z < 50) { data[(x*4) + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 100; data[(x*4)+1 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 250; data[(x*4)+2 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = y%100; data[(x*4)+3 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 250; } if(x > 50 && x < 70 && y > 0 && y < VOLUME_TEX_SIZE && z > 10 && z < 50) { data[(x*4) + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 250; data[(x*4)+1 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 250; data[(x*4)+2 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = y%100; data[(x*4)+3 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 250; } if(x > 80 && x < 100 && y > 0 && y < VOLUME_TEX_SIZE && z > 10 && z < 50) { data[(x*4) + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 250; data[(x*4)+1 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 70; data[(x*4)+2 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = y%100; data[(x*4)+3 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 250; } p = Vector3(x,y,z)- Vector3(24,24,24); test = (p.length() < 40); if(test) data[(x*4)+3 + (y * VOLUME_TEX_SIZE * 4) + (z * VOLUME_TEX_SIZE * VOLUME_TEX_SIZE * 4)] = 0; }}} glPixelStorei(GL_UNPACK_ALIGNMENT,1); glGenTextures(1, &volume_texture); glBindTexture(GL_TEXTURE_3D, volume_texture); glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_BORDER); glTexImage3D(GL_TEXTURE_3D, 0,GL_RGBA, VOLUME_TEX_SIZE, VOLUME_TEX_SIZE,VOLUME_TEX_SIZE,0, GL_RGBA, GL_UNSIGNED_BYTE,data); delete []data; cout << "volume texture created" << endl; } // ok let's start things up void init() { cout << "glew init " << endl; GLenum err = glewInit(); // initialize all the OpenGL extensions glewGetExtension("glMultiTexCoord2fvARB"); if(glewGetExtension("GL_EXT_framebuffer_object") )cout << "GL_EXT_framebuffer_object support " <<