2 * Test vertex arrays with GL_NV_vertex_program
4 * Based on a stripped-down version of the isosurf demo.
5 * The vertex program is trivial: compute the resulting
6 * RGB color as a linear function of vertex XYZ.
17 #define MAXVERTS 10000
18 static float data
[MAXVERTS
][6];
19 static GLint numverts
;
23 static GLboolean useArrays
= GL_TRUE
;
24 static GLboolean useProgram
= GL_TRUE
;
25 static GLboolean useList
= GL_FALSE
;
28 static void read_surface( char *filename
)
32 f
= fopen(filename
,"r");
34 printf("couldn't read %s\n", filename
);
39 while (numverts
< MAXVERTS
) {
41 result
= fscanf( f
, "%f %f %f %f %f %f",
42 &data
[numverts
][0], &data
[numverts
][1], &data
[numverts
][2],
43 &data
[numverts
][3], &data
[numverts
][4], &data
[numverts
][5] );
50 printf("%d vertices, %d triangles\n", numverts
, numverts
-2);
51 printf("data = %p\n", (void *) data
);
58 static void Display(void)
61 glEnable(GL_VERTEX_PROGRAM_NV
);
63 glDisable(GL_VERTEX_PROGRAM_NV
);
65 glClear( GL_COLOR_BUFFER_BIT
| GL_DEPTH_BUFFER_BIT
);
68 glRotatef(xrot
, 1, 0, 0);
69 glRotatef(yrot
, 0, 1, 0);
73 glVertexAttribPointerNV( 0, 3, GL_FLOAT
, 6 * sizeof(GLfloat
), data
);
74 glEnableClientState( GL_VERTEX_ATTRIB_ARRAY0_NV
);
75 glVertexAttribPointerNV( 2, 3, GL_FLOAT
, 6 * sizeof(GLfloat
), ((GLfloat
*) data
) + 3);
76 glEnableClientState( GL_VERTEX_ATTRIB_ARRAY2_NV
);
79 glVertexPointer( 3, GL_FLOAT
, 6 * sizeof(GLfloat
), data
);
80 glEnableClientState( GL_VERTEX_ARRAY
);
81 glNormalPointer( GL_FLOAT
, 6 * sizeof(GLfloat
), ((GLfloat
*) data
) + 3);
82 glEnableClientState( GL_NORMAL_ARRAY
);
86 /* dumb, but a good test */
87 glNewList(1,GL_COMPILE
);
88 glDrawArrays(GL_TRIANGLE_STRIP
, 0, numverts
);
93 glDrawArrays(GL_TRIANGLE_STRIP
, 0, numverts
);
96 glDisableClientState( GL_VERTEX_ATTRIB_ARRAY0_NV
);
97 glDisableClientState( GL_VERTEX_ATTRIB_ARRAY2_NV
);
98 glDisableClientState( GL_VERTEX_ARRAY
);
99 glDisableClientState( GL_NORMAL_ARRAY
);
103 glBegin(GL_TRIANGLE_STRIP
);
104 for (i
= 0; i
< numverts
; i
++) {
105 glNormal3fv( data
[i
] + 3 );
106 glVertex3fv( data
[i
] + 0 );
119 static void InitMaterials(void)
121 static float ambient
[] = {0.1, 0.1, 0.1, 1.0};
122 static float diffuse
[] = {0.5, 1.0, 1.0, 1.0};
123 static float position0
[] = {0.0, 0.0, 20.0, 0.0};
124 static float position1
[] = {0.0, 0.0, -20.0, 0.0};
125 static float front_mat_shininess
[] = {60.0};
126 static float front_mat_specular
[] = {0.2, 0.2, 0.2, 1.0};
127 static float front_mat_diffuse
[] = {0.5, 0.28, 0.38, 1.0};
129 static float back_mat_shininess[] = {60.0};
130 static float back_mat_specular[] = {0.5, 0.5, 0.2, 1.0};
131 static float back_mat_diffuse[] = {1.0, 1.0, 0.2, 1.0};
133 static float lmodel_ambient
[] = {1.0, 1.0, 1.0, 1.0};
134 static float lmodel_twoside
[] = {GL_FALSE
};
136 glLightfv(GL_LIGHT0
, GL_AMBIENT
, ambient
);
137 glLightfv(GL_LIGHT0
, GL_DIFFUSE
, diffuse
);
138 glLightfv(GL_LIGHT0
, GL_POSITION
, position0
);
141 glLightfv(GL_LIGHT1
, GL_AMBIENT
, ambient
);
142 glLightfv(GL_LIGHT1
, GL_DIFFUSE
, diffuse
);
143 glLightfv(GL_LIGHT1
, GL_POSITION
, position1
);
146 glLightModelfv(GL_LIGHT_MODEL_AMBIENT
, lmodel_ambient
);
147 glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE
, lmodel_twoside
);
149 glMaterialfv(GL_FRONT_AND_BACK
, GL_SHININESS
, front_mat_shininess
);
150 glMaterialfv(GL_FRONT_AND_BACK
, GL_SPECULAR
, front_mat_specular
);
151 glMaterialfv(GL_FRONT_AND_BACK
, GL_DIFFUSE
, front_mat_diffuse
);
152 glEnable(GL_LIGHTING
);
156 static void init_program(void)
159 * c[0..3] = modelview matrix
160 * c[4..7] = inverse modelview matrix
161 * c[30] = color scale
164 static const char prog
[] =
167 "# RGB is proportional to XYZ \n"
169 "MUL R0, v[OPOS], c[30]; \n"
170 "ADD o[COL0], R0, c[31]; \n"
172 "# Continue with typical modelview/projection\n"
173 "MOV R3, v[OPOS]; \n"
174 "DP4 o[HPOS].x, c[0], R3 ; # object x MVP -> clip\n"
175 "DP4 o[HPOS].y, c[1], R3 ;\n"
176 "DP4 o[HPOS].z, c[2], R3 ;\n"
177 "DP4 o[HPOS].w, c[3], R3 ;\n"
181 static const GLfloat scale
[4] = {2.0, 2.0, 2.0, 0.0};
182 static const GLfloat bias
[4] = {1.0, 1.0, 1.0, 0.0};
184 if (!glutExtensionSupported("GL_NV_vertex_program")) {
185 printf("Sorry, this program requires GL_NV_vertex_program\n");
189 glLoadProgramNV(GL_VERTEX_PROGRAM_NV
, 1,
190 strlen(prog
), (const GLubyte
*) prog
);
191 assert(glIsProgramNV(1));
192 glBindProgramNV(GL_VERTEX_PROGRAM_NV
, 1);
194 /* Load the program registers */
195 glTrackMatrixNV(GL_VERTEX_PROGRAM_NV
, 0, GL_MODELVIEW_PROJECTION_NV
, GL_IDENTITY_NV
);
196 glTrackMatrixNV(GL_VERTEX_PROGRAM_NV
, 4, GL_MODELVIEW
, GL_INVERSE_TRANSPOSE_NV
);
198 glProgramParameter4fvNV(GL_VERTEX_PROGRAM_NV
, 30, scale
);
199 glProgramParameter4fvNV(GL_VERTEX_PROGRAM_NV
, 31, bias
);
203 static void init(void)
207 glClearColor(0.0, 0.0, 1.0, 0.0);
208 glEnable( GL_DEPTH_TEST
);
209 glEnable(GL_NORMALIZE
);
211 read_surface( "../demos/isosurf.dat" );
216 static void Reshape(int width
, int height
)
218 glViewport(0, 0, (GLint
)width
, (GLint
)height
);
219 glMatrixMode(GL_PROJECTION
);
221 glFrustum( -1.0, 1.0, -1.0, 1.0, 5, 25 );
222 glMatrixMode(GL_MODELVIEW
);
224 glTranslatef(0, 0, -15);
229 static void Key( unsigned char key
, int x
, int y
)
237 useArrays
= !useArrays
;
238 printf("use arrays: %s\n", useArrays
? "yes" : "no");
242 printf("use list: %s\n", useList
? "yes" : "no");
245 useProgram
= !useProgram
;
246 printf("use program: %s\n", useProgram
? "yes" : "no");
253 static void SpecialKey( int key
, int x
, int y
)
278 int main(int argc
, char **argv
)
280 glutInit(&argc
, argv
);
281 glutInitDisplayMode( GLUT_DEPTH
| GLUT_RGB
| GLUT_DOUBLE
);
282 glutInitWindowPosition(0, 0);
283 glutInitWindowSize(400, 400);
284 if (glutCreateWindow("Isosurface") <= 0) {
288 glutReshapeFunc(Reshape
);
289 glutKeyboardFunc(Key
);
290 glutSpecialFunc(SpecialKey
);
291 glutDisplayFunc(Display
);