1
2 /*
3 * Simple GLUT program to measure glClear() and glutSwapBuffers() speed.
4 * Brian Paul February 15, 1997 This file in public domain.
5 */
6
7
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <math.h>
11 #include <string.h>
12 #include "glut_wrap.h"
13
14
15 static float MinPeriod = 2.0; /* 2 seconds */
16 static int ColorMode = GLUT_RGB;
17 static int Width = 400.0;
18 static int Height = 400.0;
19 static int Loops = 100;
20 static float ClearColor = 0.0;
21 static GLbitfield BufferMask = GL_COLOR_BUFFER_BIT;
22 static GLboolean SwapFlag = GL_FALSE;
23
24
25
Idle(void)26 static void Idle( void )
27 {
28 glutPostRedisplay();
29 }
30
31
Display(void)32 static void Display( void )
33 {
34 double t0, t1;
35 double clearRate;
36 double pixelRate;
37 int i;
38
39 glClearColor( ClearColor, ClearColor, ClearColor, 0.0 );
40 ClearColor += 0.1;
41 if (ClearColor>1.0)
42 ClearColor = 0.0;
43
44 if (SwapFlag) {
45 t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
46 for (i=0;i<Loops;i++) {
47 glClear( BufferMask );
48 glutSwapBuffers();
49 }
50 glFinish();
51 t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
52 }
53 else {
54 t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
55 for (i=0;i<Loops;i++) {
56 glClear( BufferMask );
57 }
58 glFinish();
59 t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
60 glutSwapBuffers();
61 }
62
63 /* NOTE: If clearspd doesn't map it's window immediately on
64 * starting, swaps will be istantaneous, so this will send Loops
65 * towards infinity. When a window is finally mapped, it may be
66 * minutes before the first call to glutSwapBuffers, making it look
67 * like there's a driver bug.
68 */
69 if (t1-t0 < MinPeriod) {
70 /* Next time do more clears to get longer elapsed time */
71 Loops *= 2;
72 return;
73 }
74
75 clearRate = Loops / (t1-t0);
76 pixelRate = clearRate * Width * Height;
77 if (SwapFlag) {
78 printf("Rate: %d clears+swaps in %gs = %g clears+swaps/s %g pixels/s\n",
79 Loops, t1-t0, clearRate, pixelRate );
80 }
81 else {
82 printf("Rate: %d clears in %gs = %g clears/s %g pixels/s\n",
83 Loops, t1-t0, clearRate, pixelRate);
84 }
85 }
86
87
Reshape(int width,int height)88 static void Reshape( int width, int height )
89 {
90 Width = width;
91 Height = height;
92 glViewport( 0, 0, width, height );
93 glMatrixMode( GL_PROJECTION );
94 glLoadIdentity();
95 glOrtho(0.0, width, 0.0, height, -1.0, 1.0);
96 glMatrixMode( GL_MODELVIEW );
97 glLoadIdentity();
98 }
99
100
Key(unsigned char key,int x,int y)101 static void Key( unsigned char key, int x, int y )
102 {
103 (void) x;
104 (void) y;
105 switch (key) {
106 case 27:
107 exit(0);
108 break;
109 }
110 glutPostRedisplay();
111 }
112
113
Init(int argc,char * argv[])114 static void Init( int argc, char *argv[] )
115 {
116 int i;
117 for (i=1; i<argc; i++) {
118 if (strcmp(argv[i],"+rgb")==0)
119 ColorMode = GLUT_RGB;
120 else if (strcmp(argv[i],"+ci")==0)
121 ColorMode = GLUT_INDEX;
122 else if (strcmp(argv[i],"-color")==0)
123 BufferMask = 0;
124 else if (strcmp(argv[i],"+depth")==0)
125 BufferMask |= GL_DEPTH_BUFFER_BIT;
126 else if (strcmp(argv[i],"+alpha")==0)
127 ColorMode = GLUT_RGB | GLUT_ALPHA;
128 else if (strcmp(argv[i],"+stencil")==0)
129 BufferMask |= GL_STENCIL_BUFFER_BIT;
130 else if (strcmp(argv[i],"+accum")==0)
131 BufferMask |= GL_ACCUM_BUFFER_BIT;
132 else if (strcmp(argv[i],"-width")==0) {
133 Width = atoi(argv[i+1]);
134 i++;
135 }
136 else if (strcmp(argv[i],"-height")==0) {
137 Height = atoi(argv[i+1]);
138 i++;
139 }
140 else if (strcmp(argv[i],"+swap")==0) {
141 SwapFlag = GL_TRUE;
142 }
143 else if (strcmp(argv[i],"-swap")==0) {
144 SwapFlag = GL_FALSE;
145 }
146 else
147 printf("Unknown option: %s\n", argv[i]);
148 }
149
150 if (ColorMode & GLUT_ALPHA)
151 printf("Mode: RGB + Alpha\n");
152 else if (ColorMode==GLUT_RGB)
153 printf("Mode: RGB\n");
154 else
155 printf("Mode: Color Index\n");
156 printf("SwapBuffers: %s\n", SwapFlag ? "yes" : "no" );
157 printf("Size: %d x %d\n", Width, Height);
158 printf("Buffers: ");
159 if (BufferMask & GL_COLOR_BUFFER_BIT) printf("color ");
160 if (BufferMask & GL_DEPTH_BUFFER_BIT) printf("depth ");
161 if (BufferMask & GL_STENCIL_BUFFER_BIT) printf("stencil ");
162 if (BufferMask & GL_ACCUM_BUFFER_BIT) printf("accum ");
163 printf("\n");
164 }
165
166
Help(const char * program)167 static void Help( const char *program )
168 {
169 printf("%s options:\n", program);
170 printf(" +rgb RGB mode\n");
171 printf(" +ci color index mode\n");
172 printf(" -color don't clear color buffer\n");
173 printf(" +alpha clear alpha buffer\n");
174 printf(" +depth clear depth buffer\n");
175 printf(" +stencil clear stencil buffer\n");
176 printf(" +accum clear accum buffer\n");
177 printf(" +swap also do SwapBuffers\n");
178 printf(" -swap don't do SwapBuffers\n");
179 }
180
181
main(int argc,char * argv[])182 int main( int argc, char *argv[] )
183 {
184 GLint mode;
185
186 printf("For options: %s -help\n", argv[0]);
187
188 Init( argc, argv );
189
190 glutInitWindowSize( (int) Width, (int) Height );
191 glutInit( &argc, argv );
192
193 mode = ColorMode | GLUT_DOUBLE;
194 if (BufferMask & GL_STENCIL_BUFFER_BIT)
195 mode |= GLUT_STENCIL;
196 if (BufferMask & GL_ACCUM_BUFFER_BIT)
197 mode |= GLUT_ACCUM;
198 if (BufferMask & GL_DEPTH_BUFFER_BIT)
199 mode |= GLUT_DEPTH;
200
201 glutInitDisplayMode(mode);
202
203 glutCreateWindow( argv[0] );
204
205 if (argc==2 && strcmp(argv[1],"-help")==0) {
206 Help(argv[0]);
207 return 0;
208 }
209
210 glutReshapeFunc( Reshape );
211 glutKeyboardFunc( Key );
212 glutDisplayFunc( Display );
213 glutIdleFunc( Idle );
214
215 glutMainLoop();
216 return 0;
217 }
218