simple texture compression test

2 files changed, 274 insertions, 0 deletions

diff --git a/progs/tests/Makefile b/progs/tests/Makefile
index 79eaf6f..7f6655d 100644
--- a/progs/tests/Makefile
+++ b/progs/tests/Makefile
@@ -58,6 +58,7 @@ SOURCES = \
 	stencil_wrap.c \
 	subtexrate.c \
 	tex1d.c \
+	texcompress2.c \
 	texfilt.c \
 	texline.c \
 	texobjshare.c \
diff --git a/progs/tests/texcompress2.c b/progs/tests/texcompress2.c
new file mode 100644
index 0000000..e2eed75
--- /dev/null
+++ b/progs/tests/texcompress2.c
@@ -0,0 +1,273 @@
+/*
+ * Test texture compression.
+ */
+
+
+#define GL_GLEXT_PROTOTYPES
+#include <assert.h>
+#include <stdio.h>
+#include <GL/glut.h>
+#include <GL/glx.h>
+#include "readtex.c"
+
+#define IMAGE_FILE "../images/arch.rgb"
+
+static int ImgWidth, ImgHeight;
+static GLenum ImgFormat;
+static GLenum CompFormat;
+static GLfloat EyeDist = 5.0;
+static GLfloat Rot = 0.0;
+const GLenum Target = GL_TEXTURE_2D;
+
+
+static void
+CheckError(int line)
+{
+   GLenum err = glGetError();
+   if (err) {
+      printf("GL Error %d at line %d\n", (int) err, line);
+   }
+}
+
+
+static const char *
+LookupFormat(GLenum format)
+{
+   switch (format) {
+   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
+      return "GL_COMPRESSED_RGB_S3TC_DXT1_EXT";
+   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
+      return "GL_COMPRESSED_RGBA_S3TC_DXT1_EXT";
+   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
+      return "GL_COMPRESSED_RGBA_S3TC_DXT3_EXT";
+   default:
+      return "other";
+   }
+}
+
+
+static void
+TestSubTex(void)
+{
+   GLboolean all = 0*GL_TRUE;
+   GLubyte *buffer;
+   GLint size, fmt;
+   int i;
+
+   glGetTexLevelParameteriv(Target, 0,
+                            GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, &size);
+   glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_INTERNAL_FORMAT, &fmt);
+
+   buffer = (GLubyte *) malloc(size);
+   glGetCompressedTexImageARB(Target, 0, buffer);
+
+   printf("Testing sub-texture replacement\n");
+   if (all)
+      glCompressedTexImage2DARB(Target, 0,
+                                fmt, ImgWidth, ImgHeight, 0,
+                                size, buffer);
+   else {
+      /* bottom half */
+      glCompressedTexSubImage2DARB(Target, 0,
+                                   0, 0, /* pos */
+                                   ImgWidth, ImgHeight / 2,
+                                   fmt, size/2, buffer);
+      /* top half */
+      glCompressedTexSubImage2DARB(Target, 0,
+                                   0, ImgHeight / 2, /* pos */
+                                   ImgWidth, ImgHeight / 2,
+                                   fmt, size/2, buffer + size / 2);
+   }
+
+   free(buffer);
+}
+
+
+static void
+LoadCompressedImage(const char *file)
+{
+   const GLenum filter = GL_LINEAR;
+   GLubyte *image;
+   GLint p;
+
+   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+   glPixelStorei(GL_PACK_ALIGNMENT, 1);
+
+   /*
+    * Load image and scale if needed.
+    */
+   image = LoadRGBImage( file, &ImgWidth, &ImgHeight, &ImgFormat );
+   if (!image) {
+      printf("Couldn't read %s\n", IMAGE_FILE);
+      exit(0);
+   }
+   printf("Image is %d x %d\n", ImgWidth, ImgHeight);
+
+   /* power of two */
+   assert(ImgWidth == 128 || ImgWidth == 256 || ImgWidth == 512);
+   assert(ImgWidth == 128 || ImgHeight == 256 || ImgHeight == 512);
+
+   if (ImgFormat == GL_RGB)
+      CompFormat = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
+   else
+      CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
+
+   if (ImgFormat == GL_RGBA) {
+      int i, numAlpha = 0;
+      for (i = 0; i < ImgWidth * ImgHeight; i++) {
+         if (image[i*4+3] != 0 && image[i*4+3] != 0xff) {
+            numAlpha++;
+         }
+         if (image[i*4+3] == 0)
+            image[i*4+3] = 4 * i / ImgWidth;
+      }
+      printf("Num Alpha !=0,255: %d\n", numAlpha);
+   }
+
+   CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
+
+
+   /*
+    * Give image to OpenGL and have it compress it.
+    */
+   glTexImage2D(Target, 0, CompFormat, ImgWidth, ImgHeight, 0,
+                ImgFormat, GL_UNSIGNED_BYTE, image);
+   CheckError(__LINE__);
+
+   free(image);
+
+   glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_INTERNAL_FORMAT, &p);
+   printf("Compressed Internal Format: %s (0x%x)\n", LookupFormat(p), p);
+   assert(p == CompFormat);
+
+   printf("Original size:   %d bytes\n", ImgWidth * ImgHeight * 3);
+   glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, &p);
+   printf("Compressed size: %d bytes\n", p);
+
+   glTexParameteri(Target, GL_TEXTURE_MIN_FILTER, filter);
+   glTexParameteri(Target, GL_TEXTURE_MAG_FILTER, filter);
+
+   TestSubTex();
+
+}
+
+
+static void
+Init(const char *file)
+{
+   GLint numFormats, formats[100];
+   GLint p;
+
+   if (!glutExtensionSupported("GL_ARB_texture_compression")) {
+      printf("Sorry, GL_ARB_texture_compression is required.\n");
+      exit(1);
+   }
+   if (!glutExtensionSupported("GL_EXT_texture_compression_s3tc")) {
+      printf("Sorry, GL_EXT_texture_compression_s3tc is required.\n");
+      exit(1);
+   }
+
+   printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
+   printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+
+   glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS_ARB, &numFormats);
+   glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS_ARB, formats);
+   printf("%d supported compression formats: ", numFormats);
+   for (p = 0; p < numFormats; p++)
+      printf("0x%x ", formats[p]);
+   printf("\n");
+
+   LoadCompressedImage(file);
+
+   glEnable(GL_TEXTURE_2D);
+
+   if (ImgFormat == GL_RGBA) {
+      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+      glEnable(GL_BLEND);
+   }
+}
+
+
+static void
+Reshape( int width, int height )
+{
+   glViewport( 0, 0, width, height );
+   glMatrixMode( GL_PROJECTION );
+   glLoadIdentity();
+   glFrustum(-1, 1, -1, 1, 4, 100);
+   glMatrixMode( GL_MODELVIEW );
+   glLoadIdentity();
+}
+
+
+static void
+Key( unsigned char key, int x, int y )
+{
+   (void) x;
+   (void) y;
+   switch (key) {
+      case 'd':
+         EyeDist -= 1.0;
+         if (EyeDist < 4.0)
+            EyeDist = 4.0;
+         break;
+      case 'D':
+         EyeDist += 1.0;
+         break;
+      case 'z':
+         Rot += 5.0;
+         break;
+      case 'Z':
+         Rot -= 5.0;
+         break;
+      case 27:
+         exit(0);
+         break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+Draw( void )
+{
+   glClearColor(0.3, 0.3, .8, 0);
+   glClear(GL_COLOR_BUFFER_BIT);
+
+   glPushMatrix();
+   glTranslatef(0, 0, -(EyeDist+0.01));
+   glRotatef(Rot, 0, 0, 1);
+   glBegin(GL_POLYGON);
+   glTexCoord2f(0, 0);  glVertex2f(-1, -1);
+   glTexCoord2f(1, 0);  glVertex2f( 1, -1);
+   glTexCoord2f(1, 1);  glVertex2f( 1,  1);
+   glTexCoord2f(0, 1);  glVertex2f(-1,  1);
+   glEnd();
+   glPopMatrix();
+
+   glutSwapBuffers();
+}
+
+
+int
+main( int argc, char *argv[] )
+{
+   glutInit( &argc, argv );
+   glutInitWindowSize( 600, 600 );
+
+   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE);
+
+   glutCreateWindow(argv[0]);
+
+   glutReshapeFunc( Reshape );
+   glutKeyboardFunc( Key );
+   glutDisplayFunc( Draw );
+
+   if (argc > 1)
+      Init(argv[1]);
+   else
+      Init(IMAGE_FILE);
+
+   glutMainLoop();
+   return 0;
+}