#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <GL/glut.h>
static float MinPeriod = 2.0;
static float Width = 400.0;
static float Height = 400.0;
static int Loops = 1;
static int Size = 50;
static int Texture = 0;
static void Idle( void )
{
glutPostRedisplay();
}
static void Display( void )
{
float x, y;
float xStep;
float yStep;
double t0, t1;
double triRate;
double pixelRate;
int triCount;
int i;
float red[3] = { 1.0, 0.0, 0.0 };
float blue[3] = { 0.0, 0.0, 1.0 };
xStep = yStep = sqrt( 2.0 * Size );
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
triCount = 0;
t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
if (Texture) {
float uStep = xStep / Width;
float vStep = yStep / Height;
float u, v;
for (i=0; i<Loops; i++) {
for (y=1.0, v=0.0f; y<Height-yStep; y+=yStep, v+=vStep) {
glBegin(GL_TRIANGLE_STRIP);
for (x=1.0, u=0.0f; x<Width; x+=xStep, u+=uStep) {
glColor3fv(red);
glTexCoord2f(u, v);
glVertex2f(x, y);
glColor3fv(blue);
glTexCoord2f(u, v+vStep);
glVertex2f(x, y+yStep);
triCount += 2;
}
glEnd();
triCount -= 2;
}
}
}
else {
for (i=0; i<Loops; i++) {
for (y=1.0; y<Height-yStep; y+=yStep) {
glBegin(GL_TRIANGLE_STRIP);
for (x=1.0; x<Width; x+=xStep) {
glColor3fv(red);
glVertex2f(x, y);
glColor3fv(blue);
glVertex2f(x, y+yStep);
triCount += 2;
}
glEnd();
triCount -= 2;
}
}
}
glFinish();
t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
if (t1-t0 < MinPeriod) {
Loops *= 2;
return;
}
triRate = triCount / (t1-t0);
pixelRate = triRate * Size;
printf("Rate: %d tri in %gs = %g tri/s %d pixels/s\n",
triCount, t1-t0, triRate, (int)pixelRate);
glutSwapBuffers();
}
static void Reshape( int width, int height )
{
Width = width;
Height = height;
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glOrtho(0.0, width, 0.0, height, -1.0, 1.0);
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
}
static void Key( unsigned char key, int x, int y )
{
(void) x;
(void) y;
switch (key) {
case 27:
exit(0);
break;
}
glutPostRedisplay();
}
static void LoadTex(int comp, int filter)
{
GLubyte *pixels;
int x, y;
pixels = (GLubyte *) malloc(4*256*256);
for (y = 0; y < 256; ++y)
for (x = 0; x < 256; ++x) {
pixels[(y*256+x)*4+0] = (int)(128.5 + 127.0 * cos(0.024544 * x));
pixels[(y*256+x)*4+1] = 255;
pixels[(y*256+x)*4+2] = (int)(128.5 + 127.0 * cos(0.024544 * y));
pixels[(y*256+x)*4+3] = 255;
}
glEnable(GL_TEXTURE_2D);
glTexImage2D(GL_TEXTURE_2D, 0, comp, 256, 256, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
printf("Texture: GL_MODULATE, %d comps, %s\n", comp, filter == GL_NEAREST ? "GL_NEAREST" : "GL_LINEAR");
}
static void Init( int argc, char *argv[] )
{
GLint shade;
GLint rBits, gBits, bBits;
int filter = GL_NEAREST, comp = 3;
int i;
for (i=1; i<argc; i++) {
if (strcmp(argv[i],"-dither")==0)
glDisable(GL_DITHER);
else if (strcmp(argv[i],"+dither")==0)
glEnable(GL_DITHER);
else if (strcmp(argv[i],"+smooth")==0)
glShadeModel(GL_SMOOTH);
else if (strcmp(argv[i],"+flat")==0)
glShadeModel(GL_FLAT);
else if (strcmp(argv[i],"+depth")==0)
glEnable(GL_DEPTH_TEST);
else if (strcmp(argv[i],"-depth")==0)
glDisable(GL_DEPTH_TEST);
else if (strcmp(argv[i],"-size")==0) {
Size = atoi(argv[i+1]);
i++;
}
else if (strcmp(argv[i],"-texture")==0)
Texture = 0;
else if (strcmp(argv[i],"+texture")==0)
Texture = 1;
else if (strcmp(argv[i],"-linear")==0)
filter = GL_NEAREST;
else if (strcmp(argv[i],"+linear")==0)
filter = GL_LINEAR;
else if (strcmp(argv[i],"-persp")==0)
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
else if (strcmp(argv[i],"+persp")==0)
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
else if (strcmp(argv[i],"-comp")==0) {
comp = atoi(argv[i+1]);
i++;
}
else
printf("Unknown option: %s\n", argv[i]);
}
glGetIntegerv(GL_SHADE_MODEL, &shade);
printf("Dither: %s\n", glIsEnabled(GL_DITHER) ? "on" : "off");
printf("ShadeModel: %s\n", (shade==GL_FLAT) ? "flat" : "smooth");
printf("DepthTest: %s\n", glIsEnabled(GL_DEPTH_TEST) ? "on" : "off");
printf("Size: %d pixels\n", Size);
if (Texture)
LoadTex(comp, filter);
glGetIntegerv(GL_RED_BITS, &rBits);
glGetIntegerv(GL_GREEN_BITS, &gBits);
glGetIntegerv(GL_BLUE_BITS, &bBits);
printf("RedBits: %d GreenBits: %d BlueBits: %d\n", rBits, gBits, bBits);
}
static void Help( const char *program )
{
printf("%s options:\n", program);
printf(" +/-dither enable/disable dithering\n");
printf(" +/-depth enable/disable depth test\n");
printf(" +flat flat shading\n");
printf(" +smooth smooth shading\n");
printf(" -size pixels specify pixels/triangle\n");
printf(" +/-texture enable/disable texture\n");
printf(" -comp n texture format\n");
printf(" +/-linear bilinear texture filter\n");
printf(" +/-persp perspective correction hint\n");
}
int main( int argc, char *argv[] )
{
printf("For options: %s -help\n", argv[0]);
glutInit( &argc, argv );
glutInitWindowSize( (int) Width, (int) Height );
glutInitWindowPosition( 0, 0 );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
glutCreateWindow( argv[0] );
if (argc==2 && strcmp(argv[1],"-help")==0) {
Help(argv[0]);
return 0;
}
Init( argc, argv );
glutReshapeFunc( Reshape );
glutKeyboardFunc( Key );
glutDisplayFunc( Display );
glutIdleFunc( Idle );
glutMainLoop();
return 0;
}