/* * GLSL noise demo. * * Michal Krol * 20 February 2006 * * Based on the original demo by: * Stefan Gustavson (stegu@itn.liu.se) 2004, 2005 */ #include <stdio.h> #include <stdlib.h> #include <GL/glew.h> #include "glut_wrap.h" static GLhandleARB fragShader; static GLhandleARB vertShader; static GLhandleARB program; static GLint uTime; static GLint t0 = 0; static GLint frames = 0; static GLfloat u_time = 0.0f; static void Redisplay(void) { GLint t; glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glUniform1fARB(uTime, 0.5f * u_time); glPushMatrix(); glutSolidSphere(2.0, 20, 10); glPopMatrix(); glutSwapBuffers(); frames++; t = glutGet(GLUT_ELAPSED_TIME); if (t - t0 >= 5000) { GLfloat seconds = (GLfloat) (t - t0) / 1000.0f; GLfloat fps = frames / seconds; printf("%d frames in %6.3f seconds = %6.3f FPS\n", frames, seconds, fps); fflush(stdout); t0 = t; frames = 0; } } static void Idle(void) { u_time += 0.1f; glutPostRedisplay(); } 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 Key(unsigned char key, int x, int y) { (void) x; (void) y; switch (key) { case 27: exit(0); break; } glutPostRedisplay(); } static void Init(void) { static const char *fragShaderText = "uniform float time;\n" "varying vec3 position;\n" "void main () {\n" " gl_FragColor = vec4 (vec3 (0.5 + 0.5 * noise1 (vec4 (position, time))), 1.0);\n" "}\n"; static const char *vertShaderText = "varying vec3 position;\n" "void main () {\n" " gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n" " position = 4.0 * gl_Vertex.xyz;\n" "}\n"; if (!glutExtensionSupported("GL_ARB_fragment_shader")) { printf("Sorry, this demo requires GL_ARB_fragment_shader\n"); exit(1); } if (!glutExtensionSupported("GL_ARB_shader_objects")) { printf("Sorry, this demo requires GL_ARB_shader_objects\n"); exit(1); } if (!glutExtensionSupported("GL_ARB_shading_language_100")) { printf("Sorry, this demo requires GL_ARB_shading_language_100\n"); exit(1); } if (!glutExtensionSupported("GL_ARB_vertex_shader")) { printf("Sorry, this demo requires GL_ARB_vertex_shader\n"); exit(1); } fragShader = glCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB); glShaderSourceARB(fragShader, 1, &fragShaderText, NULL); glCompileShaderARB(fragShader); vertShader = glCreateShaderObjectARB(GL_VERTEX_SHADER_ARB); glShaderSourceARB(vertShader, 1, &vertShaderText, NULL); glCompileShaderARB(vertShader); program = glCreateProgramObjectARB(); glAttachObjectARB(program, fragShader); glAttachObjectARB(program, vertShader); glLinkProgramARB(program); glUseProgramObjectARB(program); uTime = glGetUniformLocationARB(program, "time"); glClearColor(0.0f, 0.1f, 0.3f, 1.0f); glEnable(GL_CULL_FACE); glEnable(GL_DEPTH_TEST); printf("GL_RENDERER = %s\n", (const char *) glGetString(GL_RENDERER)); } int main(int argc, char *argv[]) { glutInit(&argc, argv); glutInitWindowSize(200, 200); glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); glutCreateWindow(argv[0]); glutReshapeFunc(Reshape); glutKeyboardFunc(Key); glutDisplayFunc(Redisplay); glutIdleFunc(Idle); glewInit(); Init(); glutMainLoop(); return 0; }