/** * Procedural Bump Mapping demo. Uses the example shaders from * chapter 11 of the OpenGL Shading Language "orange" book. * 16 Jan 2007 */ #include <assert.h> #include <string.h> #include <stdio.h> #include <stdlib.h> #include <math.h> #include <GL/glut.h> #include <GL/glu.h> #include <GL/glext.h> #include "extfuncs.h" #include "shaderutil.h" static char *FragProgFile = "CH11-bumpmap.frag"; static char *VertProgFile = "CH11-bumpmap.vert"; /* program/shader objects */ static GLuint fragShader; static GLuint vertShader; static GLuint program; static struct uniform_info Uniforms[] = { { "LightPosition", 3, GL_FLOAT, { 0.57737, 0.57735, 0.57735, 0.0 }, -1 }, { "SurfaceColor", 3, GL_FLOAT, { 0.8, 0.8, 0.2, 0 }, -1 }, { "BumpDensity", 1, GL_FLOAT, { 10.0, 0, 0, 0 }, -1 }, { "BumpSize", 1, GL_FLOAT, { 0.125, 0, 0, 0 }, -1 }, { "SpecularFactor", 1, GL_FLOAT, { 0.5, 0, 0, 0 }, -1 }, END_OF_UNIFORMS }; static GLint win = 0; static GLfloat xRot = 20.0f, yRot = 0.0f, zRot = 0.0f; static GLuint tangentAttrib; static GLboolean Anim = GL_FALSE; static void CheckError(int line) { GLenum err = glGetError(); if (err) { printf("GL Error %s (0x%x) at line %d\n", gluErrorString(err), (int) err, line); } } /* * Draw a square, specifying normal and tangent vectors. */ static void Square(GLfloat size) { glNormal3f(0, 0, 1); glVertexAttrib3f_func(tangentAttrib, 1, 0, 0); glBegin(GL_POLYGON); glTexCoord2f(0, 0); glVertex2f(-size, -size); glTexCoord2f(1, 0); glVertex2f( size, -size); glTexCoord2f(1, 1); glVertex2f( size, size); glTexCoord2f(0, 1); glVertex2f(-size, size); glEnd(); } static void Cube(GLfloat size) { /* +X */ glPushMatrix(); glRotatef(90, 0, 1, 0); glTranslatef(0, 0, size); Square(size); glPopMatrix(); /* -X */ glPushMatrix(); glRotatef(-90, 0, 1, 0); glTranslatef(0, 0, size); Square(size); glPopMatrix(); /* +Y */ glPushMatrix(); glRotatef(90, 1, 0, 0); glTranslatef(0, 0, size); Square(size); glPopMatrix(); /* -Y */ glPushMatrix(); glRotatef(-90, 1, 0, 0); glTranslatef(0, 0, size); Square(size); glPopMatrix(); /* +Z */ glPushMatrix(); glTranslatef(0, 0, size); Square(size); glPopMatrix(); /* -Z */ glPushMatrix(); glRotatef(180, 0, 1, 0); glTranslatef(0, 0, size); Square(size); glPopMatrix(); } static void Idle(void) { GLint t = glutGet(GLUT_ELAPSED_TIME); yRot = t * 0.05; glutPostRedisplay(); } static void Redisplay(void) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glPushMatrix(); glRotatef(xRot, 1.0f, 0.0f, 0.0f); glRotatef(yRot, 0.0f, 1.0f, 0.0f); glRotatef(zRot, 0.0f, 0.0f, 1.0f); Cube(1.5); glPopMatrix(); CheckError(__LINE__); glutSwapBuffers(); } static void Reshape(int width, int height) { glViewport(0, 0, width, height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0f, 0.0f, -15.0f); } static void CleanUp(void) { glDeleteShader_func(fragShader); glDeleteShader_func(vertShader); glDeleteProgram_func(program); glutDestroyWindow(win); } static void Key(unsigned char key, int x, int y) { const GLfloat step = 2.0; (void) x; (void) y; switch(key) { case 'a': Anim = !Anim; glutIdleFunc(Anim ? Idle : NULL); break; case 'z': zRot += step; break; case 'Z': zRot -= step; break; case 27: CleanUp(); exit(0); break; } glutPostRedisplay(); } static void SpecialKey(int key, int x, int y) { const GLfloat step = 2.0; (void) x; (void) y; switch(key) { case GLUT_KEY_UP: xRot += step; break; case GLUT_KEY_DOWN: xRot -= step; break; case GLUT_KEY_LEFT: yRot -= step; break; case GLUT_KEY_RIGHT: yRot += step; break; } glutPostRedisplay(); } static void Init(void) { if (!ShadersSupported()) exit(1); GetExtensionFuncs(); vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile); fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile); program = LinkShaders(vertShader, fragShader); glUseProgram_func(program); assert(glIsProgram_func(program)); assert(glIsShader_func(fragShader)); assert(glIsShader_func(vertShader)); assert(glGetError() == 0); CheckError(__LINE__); InitUniforms(program, Uniforms); CheckError(__LINE__); tangentAttrib = glGetAttribLocation_func(program, "Tangent"); printf("Tangent Attrib: %d\n", tangentAttrib); assert(tangentAttrib >= 0); CheckError(__LINE__); glClearColor(0.4f, 0.4f, 0.8f, 0.0f); glEnable(GL_DEPTH_TEST); glColor3f(1, 0, 0); } static void ParseOptions(int argc, char *argv[]) { int i; for (i = 1; i < argc; i++) { if (strcmp(argv[i], "-fs") == 0) { FragProgFile = argv[i+1]; } else if (strcmp(argv[i], "-vs") == 0) { VertProgFile = argv[i+1]; } } } int main(int argc, char *argv[]) { glutInit(&argc, argv); glutInitWindowPosition( 0, 0); glutInitWindowSize(400, 400); glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); win = glutCreateWindow(argv[0]); glutReshapeFunc(Reshape); glutKeyboardFunc(Key); glutSpecialFunc(SpecialKey); glutDisplayFunc(Redisplay); ParseOptions(argc, argv); Init(); glutMainLoop(); return 0; }