Initial demo of GL_EXT_texture_filter_anisotropic extension.

2 files changed, 223 insertions, 3 deletions

diff --git a/progs/demos/Makefile.X11 b/progs/demos/Makefile.X11
index 2a85de5..351abf5 100644
--- a/progs/demos/Makefile.X11
+++ b/progs/demos/Makefile.X11
@@ -1,4 +1,4 @@
-# $Id: Makefile.X11,v 1.17 2001/02/20 17:04:52 brianp Exp $
+# $Id: Makefile.X11,v 1.18 2001/03/22 15:24:15 gareth Exp $
 
 # Mesa 3-D graphics library
 # Version:  3.5
@@ -18,7 +18,8 @@ OSMESA_LIBS = -L$(LIBDIR) -lglut -lOSMesa -lGLU -lGL $(APP_LIB_DEPS)
 
 LIB_DEP = $(LIBDIR)/$(GL_LIB) $(LIBDIR)/$(GLU_LIB) $(LIBDIR)/$(GLUT_LIB)
 
-PROGS = bounce \
+PROGS = anisotropic \
+	bounce \
 	clearspd \
 	cubemap \
 	drawpix \
@@ -100,4 +101,3 @@ exec: $(PROGS)
 
 
 include ../Make-config
-
diff --git a/progs/demos/anisotropic.c b/progs/demos/anisotropic.c
new file mode 100644
index 0000000..9f67c2d
--- /dev/null
+++ b/progs/demos/anisotropic.c
@@ -0,0 +1,220 @@
+/* $Id: anisotropic.c,v 1.1 2001/03/22 15:24:15 gareth Exp $ */
+
+/*
+ * GL_ARB_texture_filter_anisotropic demo
+ *
+ * Gareth Hughes
+ * March 2001
+ *
+ * Copyright (C) 2000  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/* This is a fairly early version.  All it does is draw a couple of
+ * textured quads with different forms of texture filtering.  Eventually,
+ * you'll be able to adjust the maximum anisotropy and so on.
+ */
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <GL/glut.h>
+
+#define TEXTURE_SIZE 256
+static GLubyte image[TEXTURE_SIZE][TEXTURE_SIZE][3];
+
+static GLfloat repeat = 1.0;
+
+static GLfloat texcoords[] = {
+   0.0, 0.0,
+   0.0, 1.0,
+   1.0, 0.0,
+   1.0, 1.0
+};
+
+static GLfloat vertices[] = {
+   -400.0, -400.0,     0.0,
+   -400.0,  400.0, -7000.0,
+    400.0, -400.0,     0.0,
+    400.0,  400.0, -7000.0
+};
+
+static GLfloat maxAnisotropy;
+
+
+static void init( void )
+{
+   int i, j;
+
+   if ( !glutExtensionSupported( "GL_EXT_texture_filter_anisotropic" ) ) {
+      fprintf( stderr, "Sorry, this demo requires GL_EXT_texture_filter_anisotropic.\n" );
+      exit( 0 );
+   }
+
+   glClearColor( 0.0, 0.0, 0.0, 0.0 );
+   glShadeModel( GL_SMOOTH );
+
+   /* Init the vertex arrays.
+    */
+   glEnableClientState( GL_VERTEX_ARRAY );
+   glEnableClientState( GL_TEXTURE_COORD_ARRAY );
+
+   glVertexPointer( 3, GL_FLOAT, 0, vertices );
+   glTexCoordPointer( 2, GL_FLOAT, 0, texcoords );
+
+   /* Init the texture environment.
+    */
+   glEnable( GL_TEXTURE_2D );
+   glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE );
+
+   glMatrixMode( GL_TEXTURE );
+   glScalef( repeat, repeat, 0 );
+
+   glMatrixMode( GL_MODELVIEW );
+
+   glGetFloatv( GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &maxAnisotropy );
+   printf( "Maximum supported anisotropy: %.2f\n", maxAnisotropy );
+
+   /* Make the texture image.
+    */
+   glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
+
+   for ( i = 0 ; i < TEXTURE_SIZE ; i++ ) {
+      for ( j = 0 ; j < TEXTURE_SIZE ; j++ ) {
+	 if ( (i/4 + j/4) & 1 ) {
+	    image[i][j][0] = 0;
+	    image[i][j][1] = 0;
+	    image[i][j][2] = 0;
+	 } else {
+	    image[i][j][0] = 255;
+	    image[i][j][1] = 255;
+	    image[i][j][2] = 255;
+	 }
+      }
+   }
+
+   gluBuild2DMipmaps( GL_TEXTURE_2D, GL_RGB, TEXTURE_SIZE, TEXTURE_SIZE,
+		      GL_RGB, GL_UNSIGNED_BYTE, image );
+}
+
+static void display( void )
+{
+   GLint vp[4], w, h;
+
+   glClear( GL_COLOR_BUFFER_BIT );
+
+   glGetIntegerv( GL_VIEWPORT, vp );
+   w = vp[2] / 2;
+   h = vp[3] / 2;
+
+   /* Upper left corner:
+    */
+   glViewport( 1, h + 1, w - 2, h - 2 );
+
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+   glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, maxAnisotropy );
+
+   glDrawArrays( GL_TRIANGLE_STRIP, 0, 4 );
+
+
+   /* Upper right corner:
+    */
+   glViewport( w + 1, h + 1, w - 2, h - 2 );
+
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST );
+   glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, maxAnisotropy );
+
+   glDrawArrays( GL_TRIANGLE_STRIP, 0, 4 );
+
+
+   /* Lower left corner:
+    */
+   glViewport( 1, 1, w - 2, h - 2 );
+
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_LINEAR );
+   glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, maxAnisotropy );
+
+   glDrawArrays( GL_TRIANGLE_STRIP, 0, 4 );
+
+
+   /* Lower right corner:
+    */
+   glViewport( w + 1, 1, w - 2, h - 2 );
+
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );
+   glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, maxAnisotropy );
+
+   glDrawArrays( GL_TRIANGLE_STRIP, 0, 4 );
+
+
+   glViewport( vp[0], vp[1], vp[2], vp[3] );
+
+   glutSwapBuffers();
+}
+
+static void reshape( int w, int h )
+{
+   glViewport( 0, 0, (GLsizei) w, (GLsizei) h );
+
+   glMatrixMode( GL_PROJECTION );
+   glLoadIdentity();
+   glFrustum( -1.0, 1.0, -1.0, 1.0, 10.0, 10000.0 );
+
+   glMatrixMode( GL_MODELVIEW );
+   glLoadIdentity();
+   glTranslatef( 0.0, 0.0, -10.0 );
+}
+
+static void key( unsigned char key, int x, int y )
+{
+   (void) x; (void) y;
+
+   switch ( key ) {
+   case 27:
+      exit( 0 );
+   }
+
+   glutPostRedisplay();
+}
+
+static void usage( void )
+{
+   /* Nothing yet... */
+}
+
+int main( int argc, char **argv )
+{
+   glutInit( &argc, argv );
+   glutInitDisplayMode( GLUT_DOUBLE | GLUT_RGB );
+   glutInitWindowSize( 600, 300 );
+   glutInitWindowPosition( 0, 0 );
+   glutCreateWindow( "Anisotropic Texture Filter Demo" );
+
+   init();
+
+   glutDisplayFunc( display );
+   glutReshapeFunc( reshape );
+   glutKeyboardFunc( key );
+
+   usage();
+
+   glutMainLoop();
+
+   return 0;
+}