merge the (rest of) texmem branch
diff --git a/progs/demos/streaming_rect.c b/progs/demos/streaming_rect.c
new file mode 100644
index 0000000..86e0080
--- /dev/null
+++ b/progs/demos/streaming_rect.c
@@ -0,0 +1,322 @@
+
+/*
+ * GL_ARB_multitexture demo
+ *
+ * Command line options:
+ *    -info      print GL implementation information
+ *
+ *
+ * Brian Paul  November 1998  This program is in the public domain.
+ * Modified on 12 Feb 2002 for > 2 texture units.
+ */
+
+#define GL_GLEXT_PROTOTYPES
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <GL/glut.h>
+
+#include "readtex.h"
+
+
+#define ANIMATE 10
+#define PBO 11
+#define QUIT 100
+
+static GLboolean Animate = GL_TRUE;
+static GLboolean use_pbo = 1;
+static GLboolean whole_rect = 1;
+
+static GLfloat Drift = 0.0;
+static GLfloat drift_increment = 1/255.0;
+static GLfloat Xrot = 20.0, Yrot = 30.0;
+
+static GLuint Width = 1024;
+static GLuint Height = 512;
+
+
+static void Idle( void )
+{
+   if (Animate) {
+
+      Drift += drift_increment;
+      if (Drift >= 1.0)
+         Drift = 0.0;
+
+      glutPostRedisplay();
+   }
+}
+
+static int max( int a, int b ) { return a > b ? a : b; }
+static int min( int a, int b ) { return a < b ? a : b; }
+
+static void DrawObject()
+{
+   GLint size = Width * Height * 4;
+   
+   if (use_pbo) {
+      /* XXX: This is extremely important - semantically makes the buffer
+       * contents undefined, but in practice means that the driver can
+       * release the old copy of the texture and allocate a new one
+       * without waiting for outstanding rendering to complete.
+       */
+      glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_EXT, size, NULL, GL_STREAM_DRAW_ARB);
+
+      {
+	 char *image = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, GL_WRITE_ONLY_ARB);
+      
+	 printf("char %d\n", (unsigned char)(Drift * 255));
+
+	 memset(image, size, (unsigned char)(Drift * 255));
+      
+	 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT);
+      }
+   
+
+      /* BGRA is required for most hardware paths:
+       */
+      glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, Width, Height, 0,
+		   GL_BGRA, GL_UNSIGNED_BYTE, NULL);
+   }
+   else {
+      static char *image = NULL;
+
+      if (image == NULL) 
+	 image = malloc(size);
+
+      memset(image, size, (unsigned char)(Drift * 255));
+
+      /* BGRA should be the fast path for regular uploads as well.
+       */
+      glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, Width, Height, 0,
+		   GL_BGRA, GL_UNSIGNED_BYTE, image);
+   }
+
+   {
+      int x,y,w,h;
+
+      if (whole_rect) {
+	 x = y = 0;
+	 w = Width;
+	 h = Height;
+      }
+      else {
+	 x = y = 0;
+	 w = min(10, Width);
+	 h = min(10, Height);
+      }
+
+      glBegin(GL_QUADS);
+
+      glTexCoord2f( x, y);
+      glVertex2f( x, y );
+
+      glTexCoord2f( x, y + h);
+      glVertex2f( x, y + h);
+
+      glTexCoord2f( x + w + .5, y + h);
+      glVertex2f( x + w, y + h );
+
+      glTexCoord2f( x + w, y + .5);
+      glVertex2f( x + w, y );
+
+      glEnd();
+   }
+}
+
+
+
+static void Display( void )
+{
+   static GLint T0 = 0;
+   static GLint Frames = 0;
+   GLint t;
+
+   glClear( GL_COLOR_BUFFER_BIT );
+
+   glPushMatrix();
+      DrawObject();
+   glPopMatrix();
+
+   glutSwapBuffers();
+
+   Frames++;
+
+   t = glutGet(GLUT_ELAPSED_TIME);
+   if (t - T0 >= 1000) {
+      GLfloat seconds = (t - T0) / 1000.0;
+
+      GLfloat fps = Frames / seconds;
+      printf("%d frames in %6.3f seconds = %6.3f FPS\n", Frames, seconds, fps);
+
+      drift_increment = 2.2 * seconds / Frames;
+      T0 = t;
+      Frames = 0;
+   }
+}
+
+
+static void Reshape( int width, int height )
+{
+   glViewport( 0, 0, width, height );
+   glMatrixMode( GL_PROJECTION );
+   glLoadIdentity();
+/*    glFrustum( -1.0, 1.0, -1.0, 1.0, 10.0, 100.0 ); */
+   gluOrtho2D( 0, width, height, 0 );
+   glMatrixMode( GL_MODELVIEW );
+   glLoadIdentity();
+   glTranslatef(0.375, 0.375, 0);
+}
+
+
+static void ModeMenu(int entry)
+{
+   if (entry==ANIMATE) {
+      Animate = !Animate;
+   }
+   else if (entry==PBO) {
+      use_pbo = !use_pbo;
+   }
+   else if (entry==QUIT) {
+      exit(0);
+   }
+
+   glutPostRedisplay();
+}
+
+
+static void Key( unsigned char key, int x, int y )
+{
+   (void) x;
+   (void) y;
+   switch (key) {
+      case 27:
+         exit(0);
+         break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void SpecialKey( int key, int x, int y )
+{
+   float step = 3.0;
+   (void) x;
+   (void) y;
+
+   switch (key) {
+      case GLUT_KEY_UP:
+         Xrot += step;
+         break;
+      case GLUT_KEY_DOWN:
+         Xrot -= step;
+         break;
+      case GLUT_KEY_LEFT:
+         Yrot += step;
+         break;
+      case GLUT_KEY_RIGHT:
+         Yrot -= step;
+         break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void Init( int argc, char *argv[] )
+{
+   const char *exten = (const char *) glGetString(GL_EXTENSIONS);
+   GLuint texObj, DrawPBO;
+   GLint size;
+
+
+   if (!strstr(exten, "GL_ARB_multitexture")) {
+      printf("Sorry, GL_ARB_multitexture not supported by this renderer.\n");
+      exit(1);
+   }
+
+   glGetIntegerv(GL_MAX_TEXTURE_SIZE, &size);
+   printf("%d x %d max texture size\n", size, size);
+
+   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+
+   /* allocate two texture objects */
+   glGenTextures(1, &texObj);
+
+   /* setup the texture objects */
+   glActiveTextureARB(GL_TEXTURE0_ARB);
+   glBindTexture(GL_TEXTURE_RECTANGLE_ARB, texObj);
+
+   glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+   glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+   glGenBuffersARB(1, &DrawPBO);
+
+   glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, DrawPBO);
+   glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_EXT,
+		   Width * Height * 4, NULL, GL_STREAM_DRAW);
+
+   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+
+   glEnable(GL_TEXTURE_RECTANGLE_ARB);
+
+   glShadeModel(GL_SMOOTH);
+   glClearColor(0.3, 0.3, 0.4, 1.0);
+
+   if (argc > 1 && strcmp(argv[1], "-info")==0) {
+      printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
+      printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
+      printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
+      printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
+   }
+}
+
+
+int main( int argc, char *argv[] )
+{
+   GLint i;
+
+   glutInit( &argc, argv );
+
+   for (i = 1; i < argc; i++) {
+      if (strcmp(argv[i], "-w") == 0) {
+         Width = atoi(argv[i+1]);
+         if (Width <= 0) {
+            printf("Error, bad width\n");
+            exit(1);
+         }
+         i++;
+      }
+      else if (strcmp(argv[i], "-h") == 0) {
+         Height = atoi(argv[i+1]);
+         if (Height <= 0) {
+            printf("Error, bad height\n");
+            exit(1);
+         }
+         i++;
+      }
+   }
+
+   glutInitWindowSize( Width, Height );
+   glutInitWindowPosition( 0, 0 );
+   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
+   glutCreateWindow(argv[0] );
+
+   Init( argc, argv );
+
+   glutReshapeFunc( Reshape );
+   glutKeyboardFunc( Key );
+   glutSpecialFunc( SpecialKey );
+   glutDisplayFunc( Display );
+   glutIdleFunc( Idle );
+
+   glutCreateMenu(ModeMenu);
+   glutAddMenuEntry("Toggle Animation", ANIMATE);
+   glutAddMenuEntry("Toggle PBO", PBO);
+   glutAddMenuEntry("Quit", QUIT);
+   glutAttachMenu(GLUT_RIGHT_BUTTON);
+
+   glutMainLoop();
+   return 0;
+}