2 * Test OpenGL 2.0 dx/dy functions for texcoords.
6 * NOTE: resize the window to observe how the partial derivatives of
7 * the texcoords change.
18 #include "shaderutil.h"
21 static char *FragProgFile = NULL;
22 static char *VertProgFile = NULL;
23 static GLuint fragShader;
24 static GLuint vertShader;
25 static GLuint program;
26 static GLuint SphereList, RectList, CurList;
28 static GLboolean anim = GL_TRUE;
29 static GLfloat xRot = 0.0f, yRot = 0.0f;
35 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
38 glRotatef(xRot, 1.0f, 0.0f, 0.0f);
39 glRotatef(yRot, 0.0f, 1.0f, 0.0f);
50 yRot = glutGet(GLUT_ELAPSED_TIME) * 0.1;
56 Reshape(int width, int height)
58 glViewport(0, 0, width, height);
59 glMatrixMode(GL_PROJECTION);
61 glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
62 glMatrixMode(GL_MODELVIEW);
64 glTranslatef(0.0f, 0.0f, -15.0f);
71 glDeleteShader(fragShader);
72 glDeleteShader(vertShader);
73 glDeleteProgram(program);
74 glutDestroyWindow(win);
79 Key(unsigned char key, int x, int y)
94 if (CurList == SphereList)
109 SpecialKey(int key, int x, int y)
111 const GLfloat step = 3.0f;
137 GLUquadricObj *obj = gluNewQuadric();
138 SphereList = glGenLists(1);
139 gluQuadricTexture(obj, GL_TRUE);
140 glNewList(SphereList, GL_COMPILE);
141 gluSphere(obj, 2.0f, 30, 15);
149 RectList = glGenLists(1);
150 glNewList(RectList, GL_COMPILE);
152 glTexCoord2f(0, 0); glVertex2f(-2, -2);
153 glTexCoord2f(1, 0); glVertex2f( 2, -2);
154 glTexCoord2f(1, 1); glVertex2f( 2, 2);
155 glTexCoord2f(0, 1); glVertex2f(-2, 2);
164 static const char *fragShaderText =
166 " gl_FragColor = abs(dFdy(gl_TexCoord[0])) * 50.0;\n"
167 " // gl_FragColor = gl_TexCoord[0];\n"
169 static const char *vertShaderText =
171 " gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
172 " gl_TexCoord[0] = gl_MultiTexCoord0;\n"
175 if (!ShadersSupported())
178 vertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
179 fragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
180 program = LinkShaders(vertShader, fragShader);
182 glUseProgram(program);
184 /*assert(glGetError() == 0);*/
186 glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
187 glEnable(GL_DEPTH_TEST);
192 CurList = SphereList;
194 printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
196 assert(glIsProgram(program));
197 assert(glIsShader(fragShader));
198 assert(glIsShader(vertShader));
205 ParseOptions(int argc, char *argv[])
208 for (i = 1; i < argc; i++) {
209 if (strcmp(argv[i], "-fs") == 0) {
210 FragProgFile = argv[i+1];
212 else if (strcmp(argv[i], "-vs") == 0) {
213 VertProgFile = argv[i+1];
220 main(int argc, char *argv[])
222 glutInit(&argc, argv);
223 glutInitWindowPosition( 0, 0);
224 glutInitWindowSize(200, 200);
225 glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
226 win = glutCreateWindow(argv[0]);
228 glutReshapeFunc(Reshape);
229 glutKeyboardFunc(Key);
230 glutSpecialFunc(SpecialKey);
231 glutDisplayFunc(Redisplay);
234 ParseOptions(argc, argv);