| /** |
| * "Mandelbrot" shader demo. Uses the example shaders from |
| * chapter 15 (or 18) of the OpenGL Shading Language "orange" book. |
| * 15 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 = "CH18-mandel.frag"; |
| static char *VertProgFile = "CH18-mandel.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 }, |
| { "SpecularContribution", 1, GL_FLOAT, { 0.5, 0, 0, 0 }, -1 }, |
| { "DiffuseContribution", 1, GL_FLOAT, { 0.5, 0, 0, 0 }, -1 }, |
| { "Shininess", 1, GL_FLOAT, { 20.0, 0, 0, 0 }, -1 }, |
| /* frag */ |
| { "MaxIterations", 1, GL_FLOAT, { 12, 0, 0, 0 }, -1 }, |
| { "Zoom", 1, GL_FLOAT, { 0.125, 0, 0, 0 }, -1 }, |
| { "Xcenter", 1, GL_FLOAT, { -1.5, 0, 0, 0 }, -1 }, |
| { "Ycenter", 1, GL_FLOAT, { .005, 0, 0, 0 }, -1 }, |
| { "InnerColor", 1, GL_FLOAT_VEC3, { 1, 0, 0, 0 }, -1 }, |
| { "OuterColor1", 1, GL_FLOAT_VEC3, { 0, 1, 0, 0 }, -1 }, |
| { "OuterColor2", 1, GL_FLOAT_VEC3, { 0, 0, 1, 0 }, -1 }, |
| END_OF_UNIFORMS |
| }; |
| |
| static GLint win = 0; |
| |
| static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f; |
| |
| static GLint uZoom, uXcenter, uYcenter; |
| static GLfloat zoom = 1.0, xCenter = -1.5, yCenter = 0.0; |
| |
| |
| static void |
| Redisplay(void) |
| { |
| glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); |
| |
| /* set interactive uniform parameters */ |
| glUniform1fv(uZoom, 1, &zoom); |
| glUniform1fv(uXcenter, 1, &xCenter); |
| glUniform1fv(uYcenter, 1, &yCenter); |
| |
| 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(-1, -1); |
| glTexCoord2f(1, 0); glVertex2f( 1, -1); |
| glTexCoord2f(1, 1); glVertex2f( 1, 1); |
| glTexCoord2f(0, 1); glVertex2f(-1, 1); |
| 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, -6.0f); |
| } |
| |
| |
| 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': |
| zoom *= 0.9; |
| break; |
| case 'Z': |
| zoom /= 0.9; |
| break; |
| case 27: |
| CleanUp(); |
| exit(0); |
| break; |
| } |
| glutPostRedisplay(); |
| } |
| |
| |
| static void |
| SpecialKey(int key, int x, int y) |
| { |
| const GLfloat step = 0.1 * zoom; |
| |
| (void) x; |
| (void) y; |
| |
| switch(key) { |
| case GLUT_KEY_UP: |
| yCenter += step; |
| break; |
| case GLUT_KEY_DOWN: |
| yCenter -= step; |
| break; |
| case GLUT_KEY_LEFT: |
| xCenter -= step; |
| break; |
| case GLUT_KEY_RIGHT: |
| xCenter += 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); |
| |
| uZoom = glGetUniformLocation(program, "Zoom"); |
| uXcenter = glGetUniformLocation(program, "Xcenter"); |
| uYcenter = glGetUniformLocation(program, "Ycenter"); |
| |
| 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; |
| } |
| |