cg for fog program

/* 25_uniform_fog.c - OpenGL-based example demonstrating uniform exponential fog based on radial vertex distance using Cg programs from Chapter 9 of "The Cg Tutorial" (Addison-Wesley, ISBN 0321194969). */ /* Requires the OpenGL Utility Toolkit (GLUT) and Cg runtime (version 1.5 or higher). */ #include <assert.h> /* for assert */ #include <stdio.h> /* for printf and NULL */ #include <stdlib.h> /* for exit */ #include <math.h> /* for sin and cos */ #if __APPLE__ #include <GLUT/glut.h> #include <OpenGL/glext.h> #else #include <GL/glut.h> #include <GL/glext.h> #endif #include <Cg/cg.h> /* Can't include this? Is Cg Toolkit installed! */ #include <Cg/cgGL.h> #include "matrix.h" static CGcontext myCgContext; static CGprofile myCgVertexProfile, myCgFragmentProfile; static CGprogram myCgVertexProgram, myCgFragmentProgram; static CGparameter myCgVertexParam_modelViewProj, myCgVertexParam_modelView, myCgVertexParam_fogDensity, myCgFragmentParam_fogColor, myCgFragmentParam_decal; static const char *myProgramName = "25_uniform_fog", *myVertexProgramFileName = "C9E2v_fog.cg", /* Page 240 */ *myVertexProgramName = "C9E2v_fog", *myFragmentProgramFileName = "C9E1f_fog.cg", /* Page 240 */ *myFragmentProgramName = "C9E1f_fog"; static float myProjectionMatrix[16]; static float eyeHeight = 30.0f; /* Vertical height of light. */ static float eyeAngle = 0.53f; /* Angle in radians eye rotates around knight. */ static float fogDensity = 0.08f; static float fogColor[3] = { 0.8, 0.9, 0.8 }; /* Green-ish gray */ static int city_height_mode = 0; static void checkForCgError(const char *situation) { CGerror error; const char *string = cgGetLastErrorString(&error); if (error != CG_NO_ERROR) { printf("%s: %s: %s\n", myProgramName, situation, string); if (error == CG_COMPILER_ERROR) { printf("%s\n", cgGetLastListing(myCgContext)); } exit(1); } } /* Forward declared GLUT callbacks registered by main. */ static void reshape(int width, int height); static void display(void); static void menu(int item); static void keyboard(unsigned char c, int x, int y); static void mouse(int button, int state, int x, int y); static void motion(int x, int y); /* Other forward declared functions. */ static void loadDecalFromDDS(const char *filename); /* Use enum to assign unique symbolic OpenGL texture names. */ enum { TO_BOGUS = 0, TO_SIDES, TO_ROOF, TO_PAVEMENT, }; int supports_texture_anisotropy = 0; int main(int argc, char **argv) { glutInitWindowSize(800, 400); glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); glutInit(&argc, argv); glutCreateWindow(myProgramName); glutReshapeFunc(reshape); glutDisplayFunc(display); glutKeyboardFunc(keyboard); glutReshapeFunc(reshape); glutMouseFunc(mouse); glutMotionFunc(motion); /* Clear to fog color */ glClearColor(fogColor[0], fogColor[1], fogColor[2], 1.0); glEnable(GL_DEPTH_TEST); supports_texture_anisotropy = glutExtensionSupported("GL_EXT_texture_filter_anisotropic"); myCgContext = cgCreateContext(); checkForCgError("creating context"); cgGLSetDebugMode(CG_FALSE); //cgGLSetManageTextureParameters(myCgContext, CG_TRUE); cgSetParameterSettingMode(myCgContext, CG_DEFERRED_PARAMETER_SETTING); myCgVertexProfile = cgGLGetLatestProfile(CG_GL_VERTEX); cgGLSetOptimalOptions(myCgVertexProfile); checkForCgError("selecting vertex profile"); myCgVertexProgram = cgCreateProgramFromFile( myCgContext, /* Cg runtime context */ CG_SOURCE, /* Program in human-readable form */ myVertexProgramFileName, /* Name of file containing program */ myCgVertexProfile, /* Profile: OpenGL ARB vertex program */ myVertexProgramName, /* Entry function name */ NULL); /* No extra compiler options */ checkForCgError("creating vertex program from file"); cgGLLoadProgram(myCgVertexProgram); checkForCgError("loading vertex program"); #define GET_PARAM(name) \ myCgVertexParam_##name = \ cgGetNamedParameter(myCgVertexProgram, #name); \ checkForCgError("could not get " #name " parameter"); GET_PARAM(fogDensity); GET_PARAM(modelViewProj); GET_PARAM(modelView); cgSetParameter1f(myCgVertexParam_fogDensity, fogDensity); myCgFragmentProfile = cgGLGetLatestProfile(CG_GL_FRAGMENT); cgGLSetOptimalOptions(myCgFragmentProfile); checkForCgError("selecting fragment profile"); myCgFragmentProgram = cgCreateProgramFromFile( myCgContext, /* Cg runtime context */ CG_SOURCE, /* Program in human-readable form */ myFragmentProgramFileName, /* Name of file containing program */ myCgFragmentProfile, /* Profile: OpenGL ARB vertex program */ myFragmentProgramName, /* Entry function name */ NULL); /* No extra compiler options */ checkForCgError("creating fragment program from file"); cgGLLoadProgram(myCgFragmentProgram); checkForCgError("loading fragment program"); myCgFragmentParam_fogColor = cgGetNamedParameter(myCgFragmentProgram, "fogColor"); checkForCgError("could not get fogColor parameter"); cgSetParameter3fv(myCgFragmentParam_fogColor, fogColor); myCgFragmentParam_decal = cgGetNamedParameter(myCgFragmentProgram, "decal"); checkForCgError("getting decal parameter"); cgGLSetTextureParameter(myCgFragmentParam_decal, TO_SIDES); checkForCgError("setting decal 2D texture"); #define GL_TEXTURE_MAX_ANISOTROPY_EXT 0x84FE #define GL_CLAMP_TO_EDGE 0x812F /* Load the decal map the fragment program will sample. */ glBindTexture(GL_TEXTURE_2D, TO_SIDES); loadDecalFromDDS("BuildingWindows.dds"); if (supports_texture_anisotropy) { glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 8.0); } glBindTexture(GL_TEXTURE_2D, TO_ROOF); loadDecalFromDDS("BuildingRoof.dds"); if (supports_texture_anisotropy) { glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 8.0); } glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glBindTexture(GL_TEXTURE_2D, TO_PAVEMENT); loadDecalFromDDS("Pavement.dds"); if (supports_texture_anisotropy) { glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 8.0); } /* Create GLUT menu. */ glutCreateMenu(menu); glutAddMenuEntry("[ ] Cycle city configuration", ' '); glutAddMenuEntry("[+] Increase fog density", ' '); glutAddMenuEntry("[-] Decrease fog density", ' '); glutAddMenuEntry("[w] Toggle wireframe", 'w'); glutAttachMenu(GLUT_RIGHT_BUTTON); glutMainLoop(); return 0; } static void reshape(int width, int height) { double aspectRatio = (float) width / (float) height; double fieldOfView = 40.0; /* Degrees */ /* Build projection matrix once. */ makePerspectiveMatrix(fieldOfView, aspectRatio, 1.0, 500.0, /* Znear and Zfar */ myProjectionMatrix); glViewport(0, 0, width, height); } /** Simple image loaders for DirectX's DirectDraw Surface (DDS) format **/ /* Structure matching the Microsoft's "DDS File Reference" documentation. */ typedef struct { int magic; /* must be "DDS\0" */ int size; /* must be 124 */ int flags; int height; int width; int pitchOrLinearSize; int depth; int mipMapCount; int reserved[11]; struct { int size; int flags; int fourCC; int bitsPerPixel; int redMask; int greenMask; int blueMask; int