/** * "Brick" shader demo. Uses the example shaders from chapter 6 of * the OpenGL Shading Language "orange" book. * 10 Jan 2007 */ #include <assert.h> #include <string.h> #include <stdio.h> #include <stdlib.h> #include <math.h> #include <GL/glew.h> #include <GL/glut.h> #include "shaderutil.h" static char *FragProgFile = "CH06-brick.frag"; static char *VertProgFile = "CH06-brick.vert"; /* program/shader objects */ static GLuint fragShader; static GLuint vertShader; static GLuint program; static struct uniform_info Uniforms[] = { /* vert */ { "LightPosition", 1, GL_FLOAT_VEC3, { 0.1, 0.1, 9.0, 0}, -1 }, /* frag */ { "BrickColor", 1, GL_FLOAT_VEC3, { 0.8, 0.2, 0.2, 0 }, -1 }, { "MortarColor", 1, GL_FLOAT_VEC3, { 0.6, 0.6, 0.6, 0 }, -1 }, { "BrickSize", 1, GL_FLOAT_VEC2, { 1.0, 0.3, 0, 0 }, -1 }, { "BrickPct", 1, GL_FLOAT_VEC2, { 0.9, 0.8, 0, 0 }, -1 }, END_OF_UNIFORMS }; static GLint win = 0; static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f; 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); glBegin(GL_POLYGON); glTexCoord2f(0, 0); glVertex2f(-2, -2); glTexCoord2f(1, 0); glVertex2f( 2, -2); glTexCoord2f(1, 1); glVertex2f( 2, 2); glTexCoord2f(0, 1); glVertex2f(-2, 2); glEnd(); glPopMatrix(); 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(fragShader); glDeleteShader(vertShader); glDeleteProgram(program); glutDestroyWindow(win); } static void Key(unsigned char key, int x, int y) { (void) x; (void) y; switch(key) { case 'z': zRot -= 1.0; break; case 'Z': zRot += 1.0; break; case 27: CleanUp(); exit(0); break; } glutPostRedisplay(); } static void SpecialKey(int key, int x, int y) { const GLfloat step = 3.0f; (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); vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile); fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile); program = LinkShaders(vertShader, fragShader); glUseProgram(program); SetUniformValues(program, Uniforms); PrintUniforms(Uniforms); assert(glGetError() == 0); glClearColor(0.4f, 0.4f, 0.8f, 0.0f); printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER)); assert(glIsProgram(program)); assert(glIsShader(fragShader)); assert(glIsShader(vertShader)); 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); glutInitWindowSize(400, 400); glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); win = glutCreateWindow(argv[0]); glewInit(); glutReshapeFunc(Reshape); glutKeyboardFunc(Key); glutSpecialFunc(SpecialKey); glutDisplayFunc(Redisplay); ParseOptions(argc, argv); Init(); glutMainLoop(); return 0; }