From f98921d344fdcab1ae603c2b2723b9cf631adcc9 Mon Sep 17 00:00:00 2001
From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Fri, 30 May 2003 15:36:04 +0000
Subject: [PATCH] display both YCbCr and RGB image (Ian)

---
 progs/tests/yuvsquare.c | 60 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 54 insertions(+), 6 deletions(-)

diff --git a/progs/tests/yuvsquare.c b/progs/tests/yuvsquare.c
index eab255b4275..494586776a0 100644
--- a/progs/tests/yuvsquare.c
+++ b/progs/tests/yuvsquare.c
@@ -19,6 +19,9 @@
 static GLfloat Xrot = 0, Yrot = 0, Zrot = 0;
 static GLint ImgWidth, ImgHeight;
 static GLushort *ImageYUV = NULL;
+static GLubyte *ImageRGB = NULL;
+static const GLuint yuvObj = 100;
+static const GLuint rgbObj = 101;
 
 
 static void DrawObject(void)
@@ -46,9 +49,20 @@ static void Display( void )
    glClear( GL_COLOR_BUFFER_BIT );
 
    glPushMatrix();
+      glTranslatef( -1.1, 0.0, -15.0 );
       glRotatef(Xrot, 1.0, 0.0, 0.0);
       glRotatef(Yrot, 0.0, 1.0, 0.0);
       glRotatef(Zrot, 0.0, 0.0, 1.0);
+      glBindTexture(GL_TEXTURE_2D, yuvObj);
+      DrawObject();
+   glPopMatrix();
+
+   glPushMatrix();
+      glTranslatef(  1.1, 0.0, -15.0 );
+      glRotatef(Xrot, 1.0, 0.0, 0.0);
+      glRotatef(Yrot, 0.0, 1.0, 0.0);
+      glRotatef(Zrot, 0.0, 0.0, 1.0);
+      glBindTexture(GL_TEXTURE_2D, rgbObj);
       DrawObject();
    glPopMatrix();
 
@@ -61,7 +75,7 @@ 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 );
+   glFrustum( -1.1, 1.1, -1.1, 1.1, 10.0, 100.0 );
    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();
    glTranslatef( 0.0, 0.0, -15.0 );
@@ -113,9 +127,9 @@ static void SpecialKey( int key, int x, int y )
 
 static void Init( int argc, char *argv[] )
 {
-   GLuint texObj = 100;
    const char *file;
    int error;
+   GLenum  format;
 
    if (!glutExtensionSupported("GL_MESA_ycbcr_texture")) {
       printf("Sorry, GL_MESA_ycbcr_texture is required\n");
@@ -124,15 +138,18 @@ static void Init( int argc, char *argv[] )
 
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
-   glBindTexture(GL_TEXTURE_2D, texObj);
-   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-
    if (argc > 1)
       file = argv[1];
    else
       file = TEXTURE_FILE;
 
+   /* First load the texture as YCbCr.
+    */
+
+   glBindTexture(GL_TEXTURE_2D, yuvObj);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
    ImageYUV = LoadYUVImage(file, &ImgWidth, &ImgHeight );
    if (!ImageYUV) {
       printf("Couldn't read %s\n", TEXTURE_FILE);
@@ -152,6 +169,35 @@ static void Init( int argc, char *argv[] )
 
    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 
+   
+
+   /* Now load the texture as RGB.
+    */
+
+   glBindTexture(GL_TEXTURE_2D, rgbObj);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+   ImageRGB = LoadRGBImage(file, &ImgWidth, &ImgHeight, &format );
+   if (!ImageRGB) {
+      printf("Couldn't read %s\n", TEXTURE_FILE);
+      exit(0);
+   }
+
+   printf("Image: %dx%d\n", ImgWidth, ImgHeight);
+
+
+   glTexImage2D(GL_TEXTURE_2D, 0,
+                format,
+		ImgWidth, ImgHeight, 0,
+                format,
+		GL_UNSIGNED_BYTE, ImageRGB);
+
+   glEnable(GL_TEXTURE_2D);
+
+   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+
+
 
    glShadeModel(GL_FLAT);
    glClearColor(0.3, 0.3, 0.4, 1.0);
@@ -162,6 +208,8 @@ static void Init( int argc, char *argv[] )
       printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
       printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
    }
+   
+   printf( "Both images should appear the same.\n" );
 }
 
 
-- 
2.30.2