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/* $Id: texwrap.c,v 1.5 2003/02/04 02:35:00 brianp Exp $ */
/*
* Test texture wrap modes.
* Press 'b' to toggle texture image borders. You should see the same
* rendering whether or not you're using borders.
*
* Brian Paul March 2001
*/
#define GL_GLEXT_PROTOTYPES
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
#ifndef GL_CLAMP_TO_BORDER
#define GL_CLAMP_TO_BORDER 0x812D
#endif
#ifndef GL_MIRRORED_REPEAT
#define GL_MIRRORED_REPEAT 0x8370
#endif
#ifndef GL_ATI_texture_mirror_once
#define GL_MIRROR_CLAMP_ATI 0x8742
#define GL_MIRROR_CLAMP_TO_EDGE_ATI 0x8743
#endif
#define BORDER_TEXTURE 1
#define NO_BORDER_TEXTURE 2
#define SIZE 8
static GLubyte BorderImage[SIZE+2][SIZE+2][4];
static GLubyte NoBorderImage[SIZE][SIZE][4];
static GLuint Border = 1;
#define WRAP_MODE(m) { m , # m, GL_TRUE, 1.0, { NULL, NULL } }
#define WRAP_EXT(m,e1,e2,v) { m , # m, GL_FALSE, v, { e1, e2 } }
struct wrap_mode {
GLenum mode;
const char * name;
GLboolean supported;
GLfloat version;
const char * extension_names[2];
};
static struct wrap_mode modes[] = {
WRAP_MODE( GL_REPEAT ),
WRAP_MODE( GL_CLAMP ),
WRAP_EXT ( GL_CLAMP_TO_EDGE, "GL_EXT_texture_edge_clamp",
"GL_SGIS_texture_edge_clamp",
1.2 ),
WRAP_EXT ( GL_CLAMP_TO_BORDER, "GL_ARB_texture_border_clamp",
"GL_SGIS_texture_border_clamp",
1.3 ),
WRAP_EXT ( GL_MIRRORED_REPEAT, "GL_ARB_texture_mirrored_repeat",
"GL_IBM_texture_mirrored_repeat",
1.4 ),
WRAP_EXT ( GL_MIRROR_CLAMP_ATI, "GL_ATI_texture_mirror_once",
NULL,
999.0 ),
WRAP_EXT ( GL_MIRROR_CLAMP_TO_EDGE_ATI, "GL_ATI_texture_mirror_once",
NULL,
999.0 ),
{ 0 }
};
static void
PrintString(const char *s)
{
while (*s) {
glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
s++;
}
}
static void Display( void )
{
GLenum i, j;
GLint offset;
GLfloat version;
/* Fill in the extensions that are supported.
*/
version = atof( (char *) glGetString( GL_VERSION ) );
for ( i = 0 ; modes[i].mode != 0 ; i++ ) {
if ( ((modes[i].extension_names[0] != NULL)
&& glutExtensionSupported(modes[i].extension_names[0]))
|| ((modes[i].extension_names[1] != NULL)
&& glutExtensionSupported(modes[i].extension_names[1])) ) {
modes[i].supported = GL_TRUE;
}
else if ( !modes[i].supported && (modes[i].version <= version) ) {
fprintf( stderr, "WARNING: OpenGL library meets minimum version\n"
" requirement for %s, but the\n"
" extension string is not advertised.\n"
" (%s%s%s)\n",
modes[i].name,
modes[i].extension_names[0],
(modes[i].extension_names[1] != NULL)
? " or " : "",
(modes[i].extension_names[1] != NULL)
? modes[i].extension_names[1] : "" );
modes[i].supported = GL_TRUE;
}
}
glClearColor(0.5, 0.5, 0.5, 1.0);
glClear( GL_COLOR_BUFFER_BIT );
#if 0
/* draw texture as image */
glDisable(GL_TEXTURE_2D);
glWindowPos2iARB(1, 1);
glDrawPixels(6, 6, GL_RGBA, GL_UNSIGNED_BYTE, (void *) TexImage);
#endif
glBindTexture(GL_TEXTURE_2D, Border ? BORDER_TEXTURE : NO_BORDER_TEXTURE);
/* loop over min/mag filters */
for (i = 0; i < 2; i++) {
offset = 0;
if (i) {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}
else {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
}
/* loop over border modes */
for (j = 0; j < modes[j].mode != 0; j++) {
const GLfloat x0 = 0, y0 = 0, x1 = 140, y1 = 140;
const GLfloat b = 0.2;
const GLfloat s0 = -b, t0 = -b, s1 = 1.0+b, t1 = 1.0+b;
if ( modes[j].supported != GL_TRUE )
continue;
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, modes[j].mode);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, modes[j].mode);
glPushMatrix();
glTranslatef(offset * 150 + 10, i * 150 + 40, 0);
offset++;
glEnable(GL_TEXTURE_2D);
glColor3f(1, 1, 1);
glBegin(GL_POLYGON);
glTexCoord2f(s0, t0); glVertex2f(x0, y0);
glTexCoord2f(s1, t0); glVertex2f(x1, y0);
glTexCoord2f(s1, t1); glVertex2f(x1, y1);
glTexCoord2f(s0, t1); glVertex2f(x0, y1);
glEnd();
/* draw red outline showing bounds of texture at s=0,1 and t=0,1 */
glDisable(GL_TEXTURE_2D);
glColor3f(1, 0, 0);
glBegin(GL_LINE_LOOP);
glVertex2f(x0 + b * (x1-x0) / (s1-s0), y0 + b * (y1-y0) / (t1-t0));
glVertex2f(x1 - b * (x1-x0) / (s1-s0), y0 + b * (y1-y0) / (t1-t0));
glVertex2f(x1 - b * (x1-x0) / (s1-s0), y1 - b * (y1-y0) / (t1-t0));
glVertex2f(x0 + b * (x1-x0) / (s1-s0), y1 - b * (y1-y0) / (t1-t0));
glEnd();
glPopMatrix();
}
}
glDisable(GL_TEXTURE_2D);
glColor3f(1, 1, 1);
offset = 0;
for (i = 0; i < modes[i].mode != 0; i++) {
if ( modes[i].supported ) {
glWindowPos2iARB( offset * 150 + 10, 5 + ((offset & 1) * 15) );
PrintString(modes[i].name);
offset++;
}
}
glutSwapBuffers();
}
static void Reshape( int width, int height )
{
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glOrtho(0, width, 0, height, -1, 1);
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
}
static void Key( unsigned char key, int x, int y )
{
(void) x;
(void) y;
switch (key) {
case 'b':
Border = !Border;
printf("Texture Border Size = %d\n", Border);
break;
case 27:
exit(0);
break;
}
glutPostRedisplay();
}
static void Init( void )
{
static const GLubyte border[4] = { 0, 255, 0, 255 };
static const GLfloat borderf[4] = { 0, 1.0, 0, 1.0 };
GLint i, j;
for (i = 0; i < SIZE+2; i++) {
for (j = 0; j < SIZE+2; j++) {
if (i == 0 || j == 0 || i == SIZE+1 || j == SIZE+1) {
/* border color */
BorderImage[i][j][0] = border[0];
BorderImage[i][j][1] = border[1];
BorderImage[i][j][2] = border[2];
BorderImage[i][j][3] = border[3];
}
else if ((i + j) & 1) {
/* white */
BorderImage[i][j][0] = 255;
BorderImage[i][j][1] = 255;
BorderImage[i][j][2] = 255;
BorderImage[i][j][3] = 255;
}
else {
/* black */
BorderImage[i][j][0] = 0;
BorderImage[i][j][1] = 0;
BorderImage[i][j][2] = 0;
BorderImage[i][j][3] = 0;
}
}
}
glBindTexture(GL_TEXTURE_2D, BORDER_TEXTURE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, SIZE+2, SIZE+2, 1,
GL_RGBA, GL_UNSIGNED_BYTE, (void *) BorderImage);
for (i = 0; i < SIZE; i++) {
for (j = 0; j < SIZE; j++) {
if ((i + j) & 1) {
/* white */
NoBorderImage[i][j][0] = 255;
NoBorderImage[i][j][1] = 255;
NoBorderImage[i][j][2] = 255;
NoBorderImage[i][j][3] = 255;
}
else {
/* black */
NoBorderImage[i][j][0] = 0;
NoBorderImage[i][j][1] = 0;
NoBorderImage[i][j][2] = 0;
NoBorderImage[i][j][3] = 0;
}
}
}
glBindTexture(GL_TEXTURE_2D, NO_BORDER_TEXTURE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, SIZE, SIZE, 0,
GL_RGBA, GL_UNSIGNED_BYTE, (void *) NoBorderImage);
glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderf);
}
int main( int argc, char *argv[] )
{
glutInit( &argc, argv );
glutInitWindowPosition( 0, 0 );
glutInitWindowSize( 800, 355 );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
glutCreateWindow(argv[0]);
glutReshapeFunc( Reshape );
glutKeyboardFunc( Key );
glutDisplayFunc( Display );
Init();
glutMainLoop();
return 0;
}
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