2 * "Toy Ball" shader demo. Uses the example shaders from
3 * chapter 11 of the OpenGL Shading Language "orange" book.
18 static char *FragProgFile = "CH11-toyball.frag.txt";
19 static char *VertProgFile = "CH11-toyball.vert.txt";
21 /* program/shader objects */
22 static GLuint fragShader;
23 static GLuint vertShader;
24 static GLuint program;
34 static struct uniform_info Uniforms[] = {
35 { "LightDir", 4, -1, { 0.57737, 0.57735, 0.57735, 0.0 } },
36 { "HVector", 4, -1, { 0.32506, 0.32506, 0.88808, 0.0 } },
37 { "BallCenter", 4, -1, { 0.0, 0.0, 0.0, 1.0 } },
38 { "SpecularColor", 4, -1, { 0.4, 0.4, 0.4, 60.0 } },
39 { "Red", 4, -1, { 0.6, 0.0, 0.0, 1.0 } },
40 { "Blue", 4, -1, { 0.0, 0.3, 0.6, 1.0 } },
41 { "Yellow", 4, -1, { 0.6, 0.5, 0.0, 1.0 } },
42 { "HalfSpace0", 4, -1, { 1.0, 0.0, 0.0, 0.2 } },
43 { "HalfSpace1", 4, -1, { 0.309016994, 0.951056516, 0.0, 0.2 } },
44 { "HalfSpace2", 4, -1, { -0.809016994, 0.587785252, 0.0, 0.2 } },
45 { "HalfSpace3", 4, -1, { -0.809016994, -0.587785252, 0.0, 0.2 } },
46 { "HalfSpace4", 4, -1, { 0.309116994, -0.951056516, 0.0, 0.2 } },
47 { "InOrOutInit", 1, -1, { -3.0, 0, 0, 0 } },
48 { "StripeWidth", 1, -1, { 0.3, 0, 0, 0 } },
49 { "FWidth", 1, -1, { 0.005, 0, 0, 0 } },
50 { NULL, 0, 0, { 0, 0, 0, 0 } }
54 static GLboolean Anim = GL_FALSE;
55 static GLfloat TexRot = 0.0;
56 static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f;
72 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
75 glRotatef(xRot, 1.0f, 0.0f, 0.0f);
76 glRotatef(yRot, 0.0f, 1.0f, 0.0f);
77 glRotatef(zRot, 0.0f, 0.0f, 1.0f);
79 glMatrixMode(GL_TEXTURE);
81 glRotatef(TexRot, 0.0f, 1.0f, 0.0f);
82 glMatrixMode(GL_MODELVIEW);
84 glutSolidSphere(2.0, 20, 10);
95 Reshape(int width, int height)
97 glViewport(0, 0, width, height);
98 glMatrixMode(GL_PROJECTION);
100 glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
101 glMatrixMode(GL_MODELVIEW);
103 glTranslatef(0.0f, 0.0f, -15.0f);
110 glDeleteShader_func(fragShader);
111 glDeleteShader_func(vertShader);
112 glDeleteProgram_func(program);
113 glutDestroyWindow(win);
118 Key(unsigned char key, int x, int y)
120 const GLfloat step = 2.0;
148 SpecialKey(int key, int x, int y)
150 const GLfloat step = 2.0;
175 LoadAndCompileShader(GLuint shader, const char *text)
179 glShaderSource_func(shader, 1, (const GLchar **) &text, NULL);
181 glCompileShader_func(shader);
183 glGetShaderiv_func(shader, GL_COMPILE_STATUS, &stat);
187 glGetShaderInfoLog_func(shader, 1000, &len, log);
188 fprintf(stderr, "brick: problem compiling shader: %s\n", log);
192 printf("Shader compiled OK\n");
198 * Read a shader from a file.
201 ReadShader(GLuint shader, const char *filename)
203 const int max = 100*1000;
205 char *buffer = (char*) malloc(max);
206 FILE *f = fopen(filename, "r");
208 fprintf(stderr, "brick: Unable to open shader file %s\n", filename);
212 n = fread(buffer, 1, max, f);
213 printf("brick: read %d bytes from shader file %s\n", n, filename);
216 LoadAndCompileShader(shader, buffer);
225 CheckLink(GLuint prog)
228 glGetProgramiv_func(prog, GL_LINK_STATUS, &stat);
232 glGetProgramInfoLog_func(prog, 1000, &len, log);
233 fprintf(stderr, "Linker error:\n%s\n", log);
236 fprintf(stderr, "Link success!\n");
247 version = (const char *) glGetString(GL_VERSION);
248 if (version[0] != '2' || version[1] != '.') {
249 printf("Warning: this program expects OpenGL 2.0\n");
252 printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
256 vertShader = glCreateShader_func(GL_VERTEX_SHADER);
257 ReadShader(vertShader, VertProgFile);
259 fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
260 ReadShader(fragShader, FragProgFile);
262 program = glCreateProgram_func();
263 glAttachShader_func(program, fragShader);
264 glAttachShader_func(program, vertShader);
265 glLinkProgram_func(program);
267 glUseProgram_func(program);
269 assert(glIsProgram_func(program));
270 assert(glIsShader_func(fragShader));
271 assert(glIsShader_func(vertShader));
274 for (i = 0; Uniforms[i].name; i++) {
276 = glGetUniformLocation_func(program, Uniforms[i].name);
277 printf("Uniform %s location: %d\n", Uniforms[i].name,
278 Uniforms[i].location);
279 switch (Uniforms[i].size) {
281 glUniform1fv_func(Uniforms[i].location, 1, Uniforms[i].value);
284 glUniform2fv_func(Uniforms[i].location, 1, Uniforms[i].value);
287 glUniform3fv_func(Uniforms[i].location, 1, Uniforms[i].value);
290 glUniform4fv_func(Uniforms[i].location, 1, Uniforms[i].value);
297 assert(glGetError() == 0);
299 glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
301 glEnable(GL_DEPTH_TEST);
308 ParseOptions(int argc, char *argv[])
311 for (i = 1; i < argc; i++) {
312 if (strcmp(argv[i], "-fs") == 0) {
313 FragProgFile = argv[i+1];
315 else if (strcmp(argv[i], "-vs") == 0) {
316 VertProgFile = argv[i+1];
323 main(int argc, char *argv[])
325 glutInit(&argc, argv);
326 glutInitWindowPosition( 0, 0);
327 glutInitWindowSize(400, 400);
328 glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
329 win = glutCreateWindow(argv[0]);
330 glutReshapeFunc(Reshape);
331 glutKeyboardFunc(Key);
332 glutSpecialFunc(SpecialKey);
333 glutDisplayFunc(Redisplay);
334 ParseOptions(argc, argv);