From bb4a9b2dcedc449f8e60f7d136b086d011ed3323 Mon Sep 17 00:00:00 2001
From: Brian <brian.paul@tungstengraphics.com>
Date: Fri, 14 Sep 2007 09:58:32 -0600
Subject: [PATCH] added copypix.c test (test glCopyPixels w/ pixel zoom)

---
 progs/demos/Makefile  |   5 +
 progs/demos/copypix.c | 248 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 253 insertions(+)
 create mode 100644 progs/demos/copypix.c

diff --git a/progs/demos/Makefile b/progs/demos/Makefile
index cf96828..7bfcefd 100644
--- a/progs/demos/Makefile
+++ b/progs/demos/Makefile
@@ -19,6 +19,7 @@ PROGS = \
 	arbocclude \
 	bounce \
 	clearspd \
+	copypix \
 	cubemap \
 	drawpix \
 	engine \
@@ -153,6 +154,10 @@ fslight.o: fslight.c extfuncs.h
 
 
 
+viewdds: viewdds.c
+	$(CC) -I$(INCDIR) $(CFLAGS) $< readtex.o $(APP_LIB_DEPS) -L. -lgltc -o $@
+
+
 clean:
 	-rm -f $(PROGS)
 	-rm -f *.o *~
diff --git a/progs/demos/copypix.c b/progs/demos/copypix.c
new file mode 100644
index 0000000..15001e8
--- /dev/null
+++ b/progs/demos/copypix.c
@@ -0,0 +1,248 @@
+/**
+ * glCopyPixels test
+ * 
+ * Brian Paul
+ * 14 Sep 2007
+ */
+
+
+#define GL_GLEXT_PROTOTYPES
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <GL/glut.h>
+
+#include "readtex.h"
+
+#define IMAGE_FILE "../images/arch.rgb"
+
+static int ImgWidth, ImgHeight;
+static GLenum ImgFormat;
+static GLubyte *Image = NULL;
+
+static int WinWidth = 800, WinHeight = 800;
+static int Xpos, Ypos;
+static int Scissor = 0;
+static float Xzoom, Yzoom;
+static GLboolean DrawFront = GL_FALSE;
+static GLboolean Dither = GL_TRUE;
+
+
+static void Reset( void )
+{
+   Xpos = Ypos = 20;
+   Scissor = 0;
+   Xzoom = Yzoom = 1.0;
+}
+
+
+static void Display( void )
+{
+   const int dx = (WinWidth - ImgWidth) / 2;
+   const int dy = (WinHeight - ImgHeight) / 2;
+
+   if (DrawFront) {
+      glDrawBuffer(GL_FRONT);
+      glReadBuffer(GL_FRONT);
+   }
+   else {
+      glDrawBuffer(GL_BACK);
+      glReadBuffer(GL_BACK);
+   }
+
+   glClear( GL_COLOR_BUFFER_BIT );
+
+   /* draw original image */
+   glWindowPos2iARB(dx, dy);                    
+   glDrawPixels(ImgWidth, ImgHeight, ImgFormat, GL_UNSIGNED_BYTE, Image);
+
+   if (Scissor)
+      glEnable(GL_SCISSOR_TEST);
+
+   /* draw copy */
+   glPixelZoom(Xzoom, Yzoom);
+   glWindowPos2iARB(Xpos, Ypos);
+   glCopyPixels(dx, dy, ImgWidth, ImgHeight, GL_COLOR);
+   glPixelZoom(1, 1);
+
+   glDisable(GL_SCISSOR_TEST);
+
+   if (DrawFront)
+      glFinish();
+   else
+      glutSwapBuffers();
+}
+
+
+static void Reshape( int width, int height )
+{
+   WinWidth = width;
+   WinHeight = height;
+
+   glViewport( 0, 0, width, height );
+   glMatrixMode( GL_PROJECTION );
+   glLoadIdentity();
+   glOrtho( 0.0, width, 0.0, height, 0.0, 2.0 );
+   glMatrixMode( GL_MODELVIEW );
+   glLoadIdentity();
+
+   glScissor(width/4, height/4, width/2, height/2);
+}
+
+
+static void Key( unsigned char key, int x, int y )
+{
+   (void) x;
+   (void) y;
+   switch (key) {
+      case ' ':
+         Reset();
+         break;
+      case 'd':
+         Dither = !Dither;
+         if (Dither)
+            glEnable(GL_DITHER);
+         else
+            glDisable(GL_DITHER);
+         break;
+      case 's':
+         Scissor = !Scissor;
+         break;
+      case 'x':
+         Xzoom -= 0.1;
+         break;
+      case 'X':
+         Xzoom += 0.1;
+         break;
+      case 'y':
+         Yzoom -= 0.1;
+         break;
+      case 'Y':
+         Yzoom += 0.1;
+         break;
+      case 'f':
+         DrawFront = !DrawFront;
+         printf("glDrawBuffer(%s)\n", DrawFront ? "GL_FRONT" : "GL_BACK");
+         break;
+      case 27:
+         exit(0);
+         break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void SpecialKey( int key, int x, int y )
+{
+   const int step = (glutGetModifiers() & GLUT_ACTIVE_SHIFT) ? 10 : 1;
+   (void) x;
+   (void) y;
+   switch (key) {
+      case GLUT_KEY_UP:
+         Ypos += step;
+         break;
+      case GLUT_KEY_DOWN:
+         Ypos -= step;
+         break;
+      case GLUT_KEY_LEFT:
+         Xpos -= step;
+         break;
+      case GLUT_KEY_RIGHT:
+         Xpos += step;
+         break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void Init( GLboolean ciMode, const char *filename )
+{
+   printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
+   printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+
+   Image = LoadRGBImage( filename, &ImgWidth, &ImgHeight, &ImgFormat );
+   if (!Image) {
+      printf("Couldn't read %s\n", filename);
+      exit(0);
+   }
+
+   if (ciMode) {
+      /* Convert RGB image to grayscale */
+      GLubyte *indexImage = (GLubyte *) malloc( ImgWidth * ImgHeight );
+      GLint i;
+      for (i=0; i<ImgWidth*ImgHeight; i++) {
+         int gray = Image[i*3] + Image[i*3+1] + Image[i*3+2];
+         indexImage[i] = gray / 3;
+      }
+      free(Image);
+      Image = indexImage;
+      ImgFormat = GL_COLOR_INDEX;
+
+      for (i=0;i<255;i++) {
+         float g = i / 255.0;
+         glutSetColor(i, g, g, g);
+      }
+   }
+
+   printf("Loaded %d by %d image\n", ImgWidth, ImgHeight );
+
+   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+   glPixelStorei(GL_UNPACK_ROW_LENGTH, ImgWidth);
+
+   Reset();
+}
+
+
+static void Usage(void)
+{
+   printf("Keys:\n");
+   printf("       SPACE  Reset Parameters\n");
+   printf("     Up/Down  Move image up/down (SHIFT for large step)\n");
+   printf("  Left/Right  Move image left/right (SHIFT for large step)\n");
+   printf("           x  Decrease X-axis PixelZoom\n");
+   printf("           X  Increase X-axis PixelZoom\n");
+   printf("           y  Decrease Y-axis PixelZoom\n");
+   printf("           Y  Increase Y-axis PixelZoom\n");
+   printf("           s  Toggle GL_SCISSOR_TEST\n");
+   printf("           f  Toggle front/back buffer drawing\n");
+   printf("         ESC  Exit\n");
+}
+
+
+int main( int argc, char *argv[] )
+{
+   GLboolean ciMode = GL_FALSE;
+   const char *filename = IMAGE_FILE;
+   int i = 1;
+
+   if (argc > i && strcmp(argv[i], "-ci")==0) {
+      ciMode = GL_TRUE;
+      i++;
+   }
+   if (argc > i) {
+      filename = argv[i];
+   }
+
+   glutInit( &argc, argv );
+   glutInitWindowPosition( 0, 0 );
+   glutInitWindowSize( WinWidth, WinHeight );
+
+   if (ciMode)
+      glutInitDisplayMode( GLUT_INDEX | GLUT_DOUBLE );
+   else
+      glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE);
+
+   glutCreateWindow(argv[0]);
+
+   Init(ciMode, filename);
+   Usage();
+
+   glutReshapeFunc( Reshape );
+   glutKeyboardFunc( Key );
+   glutSpecialFunc( SpecialKey );
+   glutDisplayFunc( Display );
+
+   glutMainLoop();
+   return 0;
+}
-- 
2.7.4