| /* |
| * Test glTexSubImage mid-way through a frame. |
| * |
| * The same texture is used for both quads but it gets redefined |
| * with glTexSubImage (or glTexImage) after the first quad. |
| */ |
| |
| |
| #include <assert.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include "GL/glew.h" |
| #include "GL/glut.h" |
| |
| static GLuint Window = 0; |
| static GLboolean Anim = GL_FALSE; |
| static GLfloat Angle = 0.0f; |
| |
| |
| |
| static void |
| first_texture(void) |
| { |
| static int width=8, height=8; |
| static GLubyte tex1[] = { |
| 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 }; |
| |
| GLubyte tex[64][3]; |
| GLint i, j; |
| |
| /* red on white */ |
| for (i=0;i<height;i++) { |
| for (j=0;j<width;j++) { |
| int p = i*width+j; |
| if (tex1[(height-i-1)*width+j]) { |
| tex[p][0] = 255; tex[p][1] = 0; tex[p][2] = 0; |
| } |
| 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 ); |
| } |
| |
| |
| static void |
| second_texture(void) |
| { |
| static int width=8, height=8; |
| |
| static GLubyte tex2[] = { |
| 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 }; |
| |
| GLubyte tex[64][3]; |
| GLint i, j; |
| |
| /* green on blue */ |
| for (i=0;i<height;i++) { |
| for (j=0;j<width;j++) { |
| int p = i*width+j; |
| if (tex2[(height-i-1)*width+j]) { |
| tex[p][0] = 0; tex[p][1] = 255; tex[p][2] = 0; |
| } |
| else { |
| tex[p][0] = 0; tex[p][1] = 0; tex[p][2] = 255; |
| } |
| } |
| } |
| #if 0 |
| glTexImage2D( GL_TEXTURE_2D, 0, 3, width, height, 0, |
| GL_RGB, GL_UNSIGNED_BYTE, tex ); |
| #else |
| glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, |
| GL_RGB, GL_UNSIGNED_BYTE, tex ); |
| #endif |
| } |
| |
| |
| |
| static void draw( void ) |
| { |
| glClear( GL_COLOR_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 ); |
| |
| first_texture(); |
| |
| glBegin( GL_POLYGON ); |
| 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(); |
| glPopMatrix(); |
| |
| /* draw second polygon */ |
| glPushMatrix(); |
| glTranslatef( 1.0, 0.0, 0.0 ); |
| glRotatef( Angle-90.0, 0.0, 1.0, 0.0 ); |
| |
| second_texture(); |
| |
| glBegin( GL_POLYGON ); |
| 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(); |
| glPopMatrix(); |
| |
| glutSwapBuffers(); |
| } |
| |
| |
| |
| static void idle( void ) |
| { |
| static double t0 = -1.; |
| double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0; |
| if (t0 < 0.0) |
| t0 = t; |
| dt = t - t0; |
| t0 = t; |
| Angle += 120.0*dt; |
| glutPostRedisplay(); |
| } |
| |
| |
| |
| /* change view Angle, exit upon ESC */ |
| static void key(unsigned char k, int x, int y) |
| { |
| (void) x; |
| (void) y; |
| switch (k) { |
| case 'a': |
| Anim = !Anim; |
| if (Anim) |
| glutIdleFunc( idle ); |
| else |
| glutIdleFunc( NULL ); |
| break; |
| case 27: |
| glutDestroyWindow(Window); |
| exit(0); |
| } |
| } |
| |
| |
| |
| /* new window size or exposure */ |
| static 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 ); |
| } |
| |
| |
| static void init( void ) |
| { |
| /* Setup texturing */ |
| glEnable( GL_TEXTURE_2D ); |
| glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL ); |
| |
| |
| glBindTexture( GL_TEXTURE_2D, 0 ); |
| 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 ); |
| } |
| |
| |
| |
| int main( int argc, char *argv[] ) |
| { |
| glutInit(&argc, argv); |
| glutInitWindowPosition(0, 0); |
| glutInitWindowSize(300, 300); |
| glutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE ); |
| |
| Window = glutCreateWindow("Texture Objects"); |
| glewInit(); |
| if (!Window) { |
| exit(1); |
| } |
| |
| init(); |
| |
| glutReshapeFunc( reshape ); |
| glutKeyboardFunc( key ); |
| if (Anim) |
| glutIdleFunc( idle ); |
| glutDisplayFunc( draw ); |
| glutMainLoop(); |
| return 0; |
| } |