2 * "Mandelbrot" shader demo. Uses the example shaders from
3 * chapter 15 (or 18) of the OpenGL Shading Language "orange" book.
16 #include "shaderutil.h"
19 static char *FragProgFile
= "CH18-mandel.frag.txt";
20 static char *VertProgFile
= "CH18-mandel.vert.txt";
22 /* program/shader objects */
23 static GLuint fragShader
;
24 static GLuint vertShader
;
25 static GLuint program
;
28 static struct uniform_info Uniforms
[] = {
30 { "LightPosition", 3, GL_FLOAT
, { 0.1, 0.1, 9.0, 0}, -1 },
31 { "SpecularContribution", 1, GL_FLOAT
, { 0.5, 0, 0, 0 }, -1 },
32 { "DiffuseContribution", 1, GL_FLOAT
, { 0.5, 0, 0, 0 }, -1 },
33 { "Shininess", 1, GL_FLOAT
, { 20.0, 0, 0, 0 }, -1 },
35 { "MaxIterations", 1, GL_FLOAT
, { 12, 0, 0, 0 }, -1 },
36 { "Zoom", 1, GL_FLOAT
, { 0.125, 0, 0, 0 }, -1 },
37 { "Xcenter", 1, GL_FLOAT
, { -1.5, 0, 0, 0 }, -1 },
38 { "Ycenter", 1, GL_FLOAT
, { .005, 0, 0, 0 }, -1 },
39 { "InnerColor", 3, GL_FLOAT
, { 1, 0, 0, 0 }, -1 },
40 { "OuterColor1", 3, GL_FLOAT
, { 0, 1, 0, 0 }, -1 },
41 { "OuterColor2", 3, GL_FLOAT
, { 0, 0, 1, 0 }, -1 },
47 static GLfloat xRot
= 0.0f
, yRot
= 0.0f
, zRot
= 0.0f
;
49 static GLint uZoom
, uXcenter
, uYcenter
;
50 static GLfloat zoom
= 1.0, xCenter
= -1.5, yCenter
= 0.0;
56 glClear(GL_COLOR_BUFFER_BIT
| GL_DEPTH_BUFFER_BIT
);
58 /* set interactive uniform parameters */
59 glUniform1fv_func(uZoom
, 1, &zoom
);
60 glUniform1fv_func(uXcenter
, 1, &xCenter
);
61 glUniform1fv_func(uYcenter
, 1, &yCenter
);
64 glRotatef(xRot
, 1.0f
, 0.0f
, 0.0f
);
65 glRotatef(yRot
, 0.0f
, 1.0f
, 0.0f
);
66 glRotatef(zRot
, 0.0f
, 0.0f
, 1.0f
);
69 glTexCoord2f(0, 0); glVertex2f(-1, -1);
70 glTexCoord2f(1, 0); glVertex2f( 1, -1);
71 glTexCoord2f(1, 1); glVertex2f( 1, 1);
72 glTexCoord2f(0, 1); glVertex2f(-1, 1);
84 Reshape(int width
, int height
)
86 glViewport(0, 0, width
, height
);
87 glMatrixMode(GL_PROJECTION
);
89 glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
90 glMatrixMode(GL_MODELVIEW
);
92 glTranslatef(0.0f
, 0.0f
, -6.0f
);
99 glDeleteShader_func(fragShader
);
100 glDeleteShader_func(vertShader
);
101 glDeleteProgram_func(program
);
102 glutDestroyWindow(win
);
107 Key(unsigned char key
, int x
, int y
)
129 SpecialKey(int key
, int x
, int y
)
131 const GLfloat step
= 0.1 * zoom
;
159 if (!ShadersSupported())
164 vertShader
= CompileShaderFile(GL_VERTEX_SHADER
, VertProgFile
);
165 fragShader
= CompileShaderFile(GL_FRAGMENT_SHADER
, FragProgFile
);
166 program
= LinkShaders(vertShader
, fragShader
);
168 glUseProgram_func(program
);
170 for (i
= 0; Uniforms
[i
].name
; i
++) {
172 = glGetUniformLocation_func(program
, Uniforms
[i
].name
);
173 printf("Uniform %s location: %d\n", Uniforms
[i
].name
,
174 Uniforms
[i
].location
);
175 switch (Uniforms
[i
].size
) {
177 glUniform1fv_func(Uniforms
[i
].location
, 1, Uniforms
[i
].value
);
180 glUniform2fv_func(Uniforms
[i
].location
, 1, Uniforms
[i
].value
);
183 glUniform3fv_func(Uniforms
[i
].location
, 1, Uniforms
[i
].value
);
186 glUniform4fv_func(Uniforms
[i
].location
, 1, Uniforms
[i
].value
);
193 uZoom
= glGetUniformLocation_func(program
, "Zoom");
194 uXcenter
= glGetUniformLocation_func(program
, "Xcenter");
195 uYcenter
= glGetUniformLocation_func(program
, "Ycenter");
197 assert(glGetError() == 0);
199 glClearColor(0.4f
, 0.4f
, 0.8f
, 0.0f
);
201 printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER
));
203 assert(glIsProgram_func(program
));
204 assert(glIsShader_func(fragShader
));
205 assert(glIsShader_func(vertShader
));
212 ParseOptions(int argc
, char *argv
[])
215 for (i
= 1; i
< argc
; i
++) {
216 if (strcmp(argv
[i
], "-fs") == 0) {
217 FragProgFile
= argv
[i
+1];
219 else if (strcmp(argv
[i
], "-vs") == 0) {
220 VertProgFile
= argv
[i
+1];
227 main(int argc
, char *argv
[])
229 glutInit(&argc
, argv
);
230 glutInitWindowPosition( 0, 0);
231 glutInitWindowSize(400, 400);
232 glutInitDisplayMode(GLUT_RGB
| GLUT_DOUBLE
| GLUT_DEPTH
);
233 win
= glutCreateWindow(argv
[0]);
234 glutReshapeFunc(Reshape
);
235 glutKeyboardFunc(Key
);
236 glutSpecialFunc(SpecialKey
);
237 glutDisplayFunc(Redisplay
);
238 ParseOptions(argc
, argv
);