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";
20 static char *VertProgFile
= "CH18-mandel.vert";
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);
82 Reshape(int width
, int height
)
84 glViewport(0, 0, width
, height
);
85 glMatrixMode(GL_PROJECTION
);
87 glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
88 glMatrixMode(GL_MODELVIEW
);
90 glTranslatef(0.0f
, 0.0f
, -6.0f
);
97 glDeleteShader_func(fragShader
);
98 glDeleteShader_func(vertShader
);
99 glDeleteProgram_func(program
);
100 glutDestroyWindow(win
);
105 Key(unsigned char key
, int x
, int y
)
127 SpecialKey(int key
, int x
, int y
)
129 const GLfloat step
= 0.1 * zoom
;
155 if (!ShadersSupported())
160 vertShader
= CompileShaderFile(GL_VERTEX_SHADER
, VertProgFile
);
161 fragShader
= CompileShaderFile(GL_FRAGMENT_SHADER
, FragProgFile
);
162 program
= LinkShaders(vertShader
, fragShader
);
164 glUseProgram_func(program
);
166 InitUniforms(program
, Uniforms
);
168 uZoom
= glGetUniformLocation_func(program
, "Zoom");
169 uXcenter
= glGetUniformLocation_func(program
, "Xcenter");
170 uYcenter
= glGetUniformLocation_func(program
, "Ycenter");
172 assert(glGetError() == 0);
174 glClearColor(0.4f
, 0.4f
, 0.8f
, 0.0f
);
176 printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER
));
178 assert(glIsProgram_func(program
));
179 assert(glIsShader_func(fragShader
));
180 assert(glIsShader_func(vertShader
));
187 ParseOptions(int argc
, char *argv
[])
190 for (i
= 1; i
< argc
; i
++) {
191 if (strcmp(argv
[i
], "-fs") == 0) {
192 FragProgFile
= argv
[i
+1];
194 else if (strcmp(argv
[i
], "-vs") == 0) {
195 VertProgFile
= argv
[i
+1];
202 main(int argc
, char *argv
[])
204 glutInit(&argc
, argv
);
205 glutInitWindowPosition( 0, 0);
206 glutInitWindowSize(400, 400);
207 glutInitDisplayMode(GLUT_RGB
| GLUT_DOUBLE
| GLUT_DEPTH
);
208 win
= glutCreateWindow(argv
[0]);
209 glutReshapeFunc(Reshape
);
210 glutKeyboardFunc(Key
);
211 glutSpecialFunc(SpecialKey
);
212 glutDisplayFunc(Redisplay
);
213 ParseOptions(argc
, argv
);