-/* $Id: texwrap.c,v 1.1 2001/03/26 19:45:57 brianp Exp $ */
+/* $Id: texwrap.c,v 1.2 2001/04/12 20:50:26 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
*/
#endif
-#define SIZE 4
-static GLubyte TexImage[SIZE+2][SIZE+2][4];
+#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;
static void
glDrawPixels(6, 6, GL_RGBA, GL_UNSIGNED_BYTE, (void *) TexImage);
#endif
- glEnable(GL_TEXTURE_2D);
+ glBindTexture(GL_TEXTURE_2D, Border ? BORDER_TEXTURE : NO_BORDER_TEXTURE);
/* loop over min/mag filters */
for (i = 0; i < 2; i++) {
/* loop over border modes */
for (j = 0; j < numModes; 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;
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, modes[j]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, modes[j]);
glPushMatrix();
glTranslatef(j * 150 + 10, i * 150 + 25, 0);
+ glEnable(GL_TEXTURE_2D);
+ glColor3f(1, 1, 1);
glBegin(GL_POLYGON);
- glTexCoord2f(-0.2, -0.2); glVertex2f( 0, 0);
- glTexCoord2f( 1.2, -0.2); glVertex2f(140, 0);
- glTexCoord2f( 1.2, 1.2); glVertex2f(140, 140);
- glTexCoord2f(-0.2, 1.2); glVertex2f( 0, 140);
+ 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);
for (i = 0; i < numModes; i++) {
glWindowPos2iMESA( i * 150 + 10, 5);
PrintString(names[i]);
(void) x;
(void) y;
switch (key) {
+ case 'b':
+ Border = !Border;
+ printf("Texture Border Size = %d\n", Border);
+ break;
case 27:
exit(0);
break;
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 */
- TexImage[i][j][0] = border[0];
- TexImage[i][j][1] = border[1];
- TexImage[i][j][2] = border[2];
- TexImage[i][j][3] = border[3];
+ 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 */
- TexImage[i][j][0] = 255;
- TexImage[i][j][1] = 255;
- TexImage[i][j][2] = 255;
- TexImage[i][j][3] = 255;
+ BorderImage[i][j][0] = 255;
+ BorderImage[i][j][1] = 255;
+ BorderImage[i][j][2] = 255;
+ BorderImage[i][j][3] = 255;
}
else {
/* black */
- TexImage[i][j][0] = 0;
- TexImage[i][j][1] = 0;
- TexImage[i][j][2] = 0;
- TexImage[i][j][3] = 0;
+ 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 *) TexImage);
+ 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);
}