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/*
* Example of using the 1.1 texture object functions.
* Also, this demo utilizes Mesa's fast texture map path.
*
* Brian Paul June 1996
*/
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <GL/glx.h>
#include <GL/gl.h>
#include "ui.h"
static GLuint TexObj[2];
static GLfloat Angle = 0.0f;
static int cnt=0,v=0;
void
draw(void)
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glColor3f(1.0, 1.0, 1.0);
/* draw first polygon */
glPushMatrix();
glTranslatef(-1.0, 0.0, 0.0);
glRotatef(Angle, 0.0, 0.0, 1.0);
glBindTexture(GL_TEXTURE_2D, TexObj[v]);
glEnable(GL_TEXTURE_2D);
glBegin(GL_QUADS);
glTexCoord2f(0.0, 0.0);
glVertex2f(-1.0, -1.0);
glTexCoord2f(1.0, 0.0);
glVertex2f(1.0, -1.0);
glTexCoord2f(1.0, 1.0);
glVertex2f(1.0, 1.0);
glTexCoord2f(0.0, 1.0);
glVertex2f(-1.0, 1.0);
glEnd();
glDisable(GL_TEXTURE_2D);
glPopMatrix();
/* draw second polygon */
glPushMatrix();
glTranslatef(1.0, 0.0, 0.0);
glRotatef(Angle - 90.0, 0.0, 1.0, 0.0);
glBindTexture(GL_TEXTURE_2D, TexObj[1-v]);
glEnable(GL_TEXTURE_2D);
glBegin(GL_QUADS);
glTexCoord2f(0.0, 0.0);
glVertex2f(-1.0, -1.0);
glTexCoord2f(1.0, 0.0);
glVertex2f(1.0, -1.0);
glTexCoord2f(1.0, 1.0);
glVertex2f(1.0, 1.0);
glTexCoord2f(0.0, 1.0);
glVertex2f(-1.0, 1.0);
glEnd();
glDisable(GL_TEXTURE_2D);
glPopMatrix();
tkSwapBuffers();
}
/* new window size or exposure */
void
reshape(int width, int height)
{
glViewport(0, 0, (GLint) width, (GLint) height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
/* glOrtho( -3.0, 3.0, -3.0, 3.0, -10.0, 10.0 ); */
glFrustum(-2.0, 2.0, -2.0, 2.0, 6.0, 20.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -8.0);
}
void bind_texture(int texobj,int image)
{
static int width = 8, height = 8;
static int color[2][3]={
{255,0,0},
{0,255,0},
};
GLubyte tex[64][3];
static GLubyte texchar[2][8*8] = {
{
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 1, 0, 0, 0,
0, 0, 0, 1, 1, 0, 0, 0,
0, 0, 0, 0, 1, 0, 0, 0,
0, 0, 0, 0, 1, 0, 0, 0,
0, 0, 0, 0, 1, 0, 0, 0,
0, 0, 0, 1, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0},
{
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 2, 2, 0, 0, 0,
0, 0, 2, 0, 0, 2, 0, 0,
0, 0, 0, 0, 0, 2, 0, 0,
0, 0, 0, 0, 2, 0, 0, 0,
0, 0, 0, 2, 0, 0, 0, 0,
0, 0, 2, 2, 2, 2, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0}};
int i,j;
glBindTexture(GL_TEXTURE_2D, texobj);
/* red on white */
for (i = 0; i < height; i++) {
for (j = 0; j < width; j++) {
int p = i * width + j;
if (texchar[image][(height - i - 1) * width + j]) {
tex[p][0] = color[image][0];
tex[p][1] = color[image][1];
tex[p][2] = color[image][2];
} else {
tex[p][0] = 255;
tex[p][1] = 255;
tex[p][2] = 255;
}
}
}
glTexImage2D(GL_TEXTURE_2D, 0, 3, width, height, 0,
GL_RGB, GL_UNSIGNED_BYTE, tex);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
/* end of texture object */
}
void
init(void)
{
glEnable(GL_DEPTH_TEST);
/* Setup texturing */
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
/* generate texture object IDs */
glGenTextures(2, TexObj);
bind_texture(TexObj[0],0);
bind_texture(TexObj[1],1);
}
void
idle(void)
{
Angle += 2.0;
if (++cnt==5) {
cnt=0;
v=!v;
}
draw();
}
/* change view angle, exit upon ESC */
GLenum key(int k, GLenum mask)
{
switch (k) {
case 'q':
case KEY_ESCAPE:
exit(0);
}
return GL_FALSE;
}
int main(int argc, char **argv)
{
return ui_loop(argc, argv, "texobj");
}
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