added support for separate read/draw buffers per context

11 files changed, 176 insertions, 150 deletions

diff --git a/src/mesa/drivers/x11/xmesaP.h b/src/mesa/drivers/x11/xmesaP.h
index 4dc8425c10..491e2fdc98 100644
--- a/src/mesa/drivers/x11/xmesaP.h
+++ b/src/mesa/drivers/x11/xmesaP.h
@@ -1,8 +1,8 @@
-/* $Id: xmesaP.h,v 1.2 1999/10/08 09:27:12 keithw Exp $ */
+/* $Id: xmesaP.h,v 1.3 1999/11/24 18:49:44 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
- * Version:  3.1
+ * Version:  3.3
  * 
  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
  * 
@@ -23,9 +23,6 @@
  * 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.
  */
-/* $XFree86: xc/lib/GL/mesa/src/X/xmesaP.h,v 1.5 1999/07/06 14:51:28 dawes Exp $ */
-
-
 
 
 #ifndef XMESAP_H
@@ -39,7 +36,7 @@
 # ifdef GLX_DIRECT_RENDERING
 #  include "dri_mesa.h"
 # endif
-# ifdef SHM
+# ifdef USE_XSHM
 #  include <X11/extensions/XShm.h>
 # endif
 #endif
@@ -127,6 +124,7 @@ struct xmesa_context {
    GLcontext *gl_ctx;		/* the core library context */
    XMesaVisual xm_visual;	/* Describes the buffers */
    XMesaBuffer xm_buffer;	/* current framebuffer */
+   XMesaBuffer xm_read_buffer;	/* current framebuffer */
 
    XMesaDisplay *display;	/* == xm_visual->display */
    GLboolean swapbytes;		/* Host byte order != display byte order? */
@@ -179,7 +177,7 @@ struct xmesa_buffer {
 				/*    0 = not available			*/
 				/*    1 = XImage support available	*/
 				/*    2 = Pixmap support available too	*/
-#ifdef SHM
+#ifdef USE_XSHM
    XShmSegmentInfo shminfo;
 #endif
 #endif
diff --git a/src/mesa/main/accum.c b/src/mesa/main/accum.c
index 1e8cce0ec3..8e6f3cae0f 100644
--- a/src/mesa/main/accum.c
+++ b/src/mesa/main/accum.c
@@ -1,8 +1,8 @@
-/* $Id: accum.c,v 1.11 1999/11/11 01:22:25 brianp Exp $ */
+/* $Id: accum.c,v 1.12 1999/11/24 18:48:30 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
- * Version:  3.1
+ * Version:  3.3
  * 
  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
  * 
@@ -70,15 +70,15 @@ void gl_alloc_accum_buffer( GLcontext *ctx )
 {
    GLint n;
 
-   if (ctx->Buffer->Accum) {
-      FREE( ctx->Buffer->Accum );
-      ctx->Buffer->Accum = NULL;
+   if (ctx->DrawBuffer->Accum) {
+      FREE( ctx->DrawBuffer->Accum );
+      ctx->DrawBuffer->Accum = NULL;
    }
 
    /* allocate accumulation buffer if not already present */
-   n = ctx->Buffer->Width * ctx->Buffer->Height * 4 * sizeof(GLaccum);
-   ctx->Buffer->Accum = (GLaccum *) MALLOC( n );
-   if (!ctx->Buffer->Accum) {
+   n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height * 4 * sizeof(GLaccum);
+   ctx->DrawBuffer->Accum = (GLaccum *) MALLOC( n );
+   if (!ctx->DrawBuffer->Accum) {
       /* unable to setup accumulation buffer */
       gl_error( ctx, GL_OUT_OF_MEMORY, "glAccum" );
    }
@@ -113,10 +113,10 @@ _mesa_ClearAccum( GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha )
  */
 static void rescale_accum( GLcontext *ctx )
 {
-   const GLuint n = ctx->Buffer->Width * ctx->Buffer->Height * 4;
+   const GLuint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height * 4;
    const GLfloat fChanMax = (1 << (sizeof(GLchan) * 8)) - 1;
    const GLfloat s = ctx->IntegerAccumScaler * (32767.0 / fChanMax);
-   GLaccum *accum = ctx->Buffer->Accum;
+   GLaccum *accum = ctx->DrawBuffer->Accum;
    GLuint i;
 
    assert(ctx->IntegerAccumMode);
@@ -143,9 +143,13 @@ _mesa_Accum( GLenum op, GLfloat value )
    
    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glAccum");
 
-   if (ctx->Visual->AccumBits==0 || !ctx->Buffer->Accum) {
-      /* No accumulation buffer! */
-      gl_warning(ctx, "Calling glAccum() without an accumulation buffer");
+   if (ctx->Visual->AccumBits == 0 || ctx->DrawBuffer != ctx->ReadBuffer) {
+      gl_error(ctx, GL_INVALID_OPERATION, "glAccum");
+      return;
+   }
+
+   if (!ctx->DrawBuffer->Accum) {
+      gl_warning(ctx, "Calling glAccum() without an accumulation buffer (low memory?)");
       return;
    }
 
@@ -174,8 +178,8 @@ _mesa_Accum( GLenum op, GLfloat value )
       /* whole window */
       xpos = 0;
       ypos = 0;
-      width = ctx->Buffer->Width;
-      height = ctx->Buffer->Height;
+      width = ctx->DrawBuffer->Width;
+      height = ctx->DrawBuffer->Height;
    }
 
    width4 = 4 * width;
@@ -189,7 +193,7 @@ _mesa_Accum( GLenum op, GLfloat value )
             if (ctx->IntegerAccumMode)
                rescale_accum(ctx);
 	    for (j = 0; j < height; j++) {
-	       GLaccum * acc = ctx->Buffer->Accum + ypos * width4 + 4 * xpos;
+	       GLaccum * acc = ctx->DrawBuffer->Accum + ypos * width4 + 4 * xpos;
                GLuint i;
 	       for (i = 0; i < width4; i++) {
                   acc[i] += intVal;
@@ -206,7 +210,7 @@ _mesa_Accum( GLenum op, GLfloat value )
             if (ctx->IntegerAccumMode)
                rescale_accum(ctx);
 	    for (j = 0; j < height; j++) {
-	       GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + 4 * xpos;
+	       GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + 4 * xpos;
                GLuint i;
 	       for (i = 0; i < width4; i++) {
                   acc[i] = (GLaccum) ( (GLfloat) acc[i] * value );
@@ -228,13 +232,13 @@ _mesa_Accum( GLenum op, GLfloat value )
          if (ctx->IntegerAccumMode) {
             /* simply add integer color values into accum buffer */
             GLuint j;
-            GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
+            GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos * 4;
             assert(ctx->IntegerAccumScaler > 0.0);
             assert(ctx->IntegerAccumScaler <= 1.0);
             for (j = 0; j < height; j++) {
                
                GLuint i, i4;
-               gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
+               gl_read_rgba_span(ctx, ctx->DrawBuffer, width, xpos, ypos, rgba);
                for (i = i4 = 0; i < width; i++, i4+=4) {
                   acc[i4+0] += rgba[i][RCOMP];
                   acc[i4+1] += rgba[i][GCOMP];
@@ -253,9 +257,9 @@ _mesa_Accum( GLenum op, GLfloat value )
             const GLfloat ascale = value * acc_scale / fChanMax;
             GLuint j;
             for (j=0;j<height;j++) {
-               GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
+               GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos * 4;
                GLuint i;
-               gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
+               gl_read_rgba_span(ctx, ctx->DrawBuffer, width, xpos, ypos, rgba);
                for (i=0;i<width;i++) {
                   *acc += (GLaccum) ( (GLfloat) rgba[i][RCOMP] * rscale );  acc++;
                   *acc += (GLaccum) ( (GLfloat) rgba[i][GCOMP] * gscale );  acc++;
@@ -288,12 +292,12 @@ _mesa_Accum( GLenum op, GLfloat value )
          if (ctx->IntegerAccumMode) {
             /* just copy values into accum buffer */
             GLuint j;
-            GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
+            GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos * 4;
             assert(ctx->IntegerAccumScaler > 0.0);
             assert(ctx->IntegerAccumScaler <= 1.0);
             for (j = 0; j < height; j++) {
                GLuint i, i4;
-               gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
+               gl_read_rgba_span(ctx, ctx->DrawBuffer, width, xpos, ypos, rgba);
                for (i = i4 = 0; i < width; i++, i4 += 4) {
                   acc[i4+0] = rgba[i][RCOMP];
                   acc[i4+1] = rgba[i][GCOMP];
@@ -313,8 +317,8 @@ _mesa_Accum( GLenum op, GLfloat value )
             const GLfloat d = 3.0 / acc_scale;
             GLuint i, j;
             for (j = 0; j < height; j++) {
-               GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
-               gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
+               GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos * 4;
+               gl_read_rgba_span(ctx, ctx->DrawBuffer, width, xpos, ypos, rgba);
                for (i=0;i<width;i++) {
                   *acc++ = (GLaccum) ((GLfloat) rgba[i][RCOMP] * rscale + d);
                   *acc++ = (GLaccum) ((GLfloat) rgba[i][GCOMP] * gscale + d);
@@ -349,7 +353,7 @@ _mesa_Accum( GLenum op, GLfloat value )
             assert(ctx->IntegerAccumScaler > 0.0);
             assert(ctx->IntegerAccumScaler <= 1.0);
             for (j = 0; j < height; j++) {
-               const GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos*4;
+               const GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos*4;
                GLuint i, i4;
                for (i = i4 = 0; i < width; i++, i4 += 4) {
                   ASSERT(acc[i4+0] < max);
@@ -376,7 +380,7 @@ _mesa_Accum( GLenum op, GLfloat value )
             const GLfloat ascale = value / acc_scale * fChanMax;
             GLuint i, j;
             for (j=0;j<height;j++) {
-               const GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos*4;
+               const GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos*4;
                for (i=0;i<width;i++) {
                   GLint r, g, b, a;
                   r = (GLint) ( (GLfloat) (*acc++) * rscale + 0.5F );
@@ -430,15 +434,15 @@ void gl_clear_accum_buffer( GLcontext *ctx )
    }
 
    /* number of pixels */
-   buffersize = ctx->Buffer->Width * ctx->Buffer->Height;
+   buffersize = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
 
-   if (!ctx->Buffer->Accum) {
+   if (!ctx->DrawBuffer->Accum) {
       /* try to alloc accumulation buffer */
-      ctx->Buffer->Accum = (GLaccum *)
+      ctx->DrawBuffer->Accum = (GLaccum *)
 	                   MALLOC( buffersize * 4 * sizeof(GLaccum) );
    }
 
-   if (ctx->Buffer->Accum) {
+   if (ctx->DrawBuffer->Accum) {
       if (ctx->Scissor.Enabled) {
 	 /* Limit clear to scissor box */
 	 GLaccum r, g, b, a;
@@ -450,12 +454,12 @@ void gl_clear_accum_buffer( GLcontext *ctx )
 	 b = (GLaccum) (ctx->Accum.ClearColor[2] * acc_scale);
 	 a = (GLaccum) (ctx->Accum.ClearColor[3] * acc_scale);
          /* size of region to clear */
-         width = 4 * (ctx->Buffer->Xmax - ctx->Buffer->Xmin + 1);
-         height = ctx->Buffer->Ymax - ctx->Buffer->Ymin + 1;
+         width = 4 * (ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1);
+         height = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin + 1;
          /* ptr to first element to clear */
-         row = ctx->Buffer->Accum
-               + 4 * (ctx->Buffer->Ymin * ctx->Buffer->Width
-                      + ctx->Buffer->Xmin);
+         row = ctx->DrawBuffer->Accum
+               + 4 * (ctx->DrawBuffer->Ymin * ctx->DrawBuffer->Width
+                      + ctx->DrawBuffer->Xmin);
          for (j=0;j<height;j++) {
             for (i=0;i<width;i+=4) {
                row[i+0] = r;
@@ -463,7 +467,7 @@ void gl_clear_accum_buffer( GLcontext *ctx )
                row[i+2] = b;
                row[i+3] = a;
 	    }
-            row += 4 * ctx->Buffer->Width;
+            row += 4 * ctx->DrawBuffer->Width;
 	 }
       }
       else {
@@ -473,14 +477,14 @@ void gl_clear_accum_buffer( GLcontext *ctx )
 	     ctx->Accum.ClearColor[2]==0.0 &&
 	     ctx->Accum.ClearColor[3]==0.0) {
 	    /* Black */
-	    MEMSET( ctx->Buffer->Accum, 0, buffersize * 4 * sizeof(GLaccum) );
+	    MEMSET( ctx->DrawBuffer->Accum, 0, buffersize * 4 * sizeof(GLaccum) );
 	 }
 	 else {
 	    /* Not black */
 	    GLaccum *acc, r, g, b, a;
 	    GLuint i;
 
-	    acc = ctx->Buffer->Accum;
+	    acc = ctx->DrawBuffer->Accum;
 	    r = (GLaccum) (ctx->Accum.ClearColor[0] * acc_scale);
 	    g = (GLaccum) (ctx->Accum.ClearColor[1] * acc_scale);
 	    b = (GLaccum) (ctx->Accum.ClearColor[2] * acc_scale);
diff --git a/src/mesa/main/blend.c b/src/mesa/main/blend.c
index 0790d65256..e042945d2c 100644
--- a/src/mesa/main/blend.c
+++ b/src/mesa/main/blend.c
@@ -1,8 +1,8 @@
-/* $Id: blend.c,v 1.9 1999/11/12 04:56:55 kendallb Exp $ */
+/* $Id: blend.c,v 1.10 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
- * Version:  3.1
+ * Version:  3.3
  * 
  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
  * 
@@ -782,7 +782,7 @@ void gl_blend_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
    }
 
    /* Read span of current frame buffer pixels */
-   gl_read_rgba_span( ctx, n, x, y, dest );
+   gl_read_rgba_span( ctx, ctx->DrawBuffer, n, x, y, dest );
 
    if (!ctx->Color.BlendFunc)
       set_blend_function(ctx);
diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index a7fbddcbdb..e41afe15ce 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -1,4 +1,4 @@
-/* $Id: context.c,v 1.22 1999/11/19 22:51:29 brianp Exp $ */
+/* $Id: context.c,v 1.23 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -1204,7 +1204,8 @@ GLcontext *gl_create_context( GLvisual *visual,
 
    ctx->DriverCtx = driver_ctx;
    ctx->Visual = visual;
-   ctx->Buffer = NULL;
+   ctx->DrawBuffer = NULL;
+   ctx->ReadBuffer = NULL;
 
    ctx->VB = gl_vb_create_for_immediate( ctx );
    if (!ctx->VB) {
@@ -1479,6 +1480,17 @@ void gl_destroy_framebuffer( GLframebuffer *buffer )
  */
 void gl_make_current( GLcontext *newCtx, GLframebuffer *buffer )
 {
+   gl_make_current2( newCtx, buffer, buffer );
+}
+
+
+/*
+ * Bind the given context to the given draw-buffer and read-buffer
+ * and make it the current context for this thread.
+ */
+void gl_make_current2( GLcontext *newCtx, GLframebuffer *drawBuffer,
+                       GLframebuffer *readBuffer )
+{
    GET_CURRENT_CONTEXT(oldCtx);
 
    /* Flush the old context
@@ -1487,9 +1499,12 @@ void gl_make_current( GLcontext *newCtx, GLframebuffer *buffer )
       ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(oldCtx, "gl_make_current");
    }
 
-   if (oldCtx && oldCtx->Buffer) {
-      /* unbind frame buffer from context */
-      oldCtx->Buffer = NULL;
+   /* unbind frame buffers from context */
+   if (oldCtx && oldCtx->DrawBuffer) {
+      oldCtx->DrawBuffer = NULL;
+   }
+   if (oldCtx && oldCtx->ReadBuffer) {
+      oldCtx->ReadBuffer = NULL;
    }
 
 #ifdef THREADS
@@ -1509,15 +1524,17 @@ void gl_make_current( GLcontext *newCtx, GLframebuffer *buffer )
 
    if (MESA_VERBOSE) fprintf(stderr, "gl_make_current()\n");
 
-   if (newCtx && buffer) {
+   if (newCtx && drawBuffer && readBuffer) {
       /* TODO: check if newCtx and buffer's visual match??? */
-      newCtx->Buffer = buffer;      /* Bind the frame buffer to the context */
+      newCtx->DrawBuffer = drawBuffer;
+      newCtx->ReadBuffer = readBuffer;
       newCtx->NewState = NEW_ALL;   /* just to be safe */
       gl_update_state( newCtx );
    }
 }
 
 
+
 /*
  * Return current context handle for the calling thread.
  */
@@ -1648,15 +1665,15 @@ _mesa_ResizeBuffersMESA( void )
    (*ctx->Driver.GetBufferSize)( ctx, &buf_width, &buf_height );
 
    /* see if size of device driver's color buffer (window) has changed */
-   if (ctx->Buffer->Width == (GLint) buf_width &&
-       ctx->Buffer->Height == (GLint) buf_height)
+   if (ctx->DrawBuffer->Width == (GLint) buf_width &&
+       ctx->DrawBuffer->Height == (GLint) buf_height)
       return;
 
    ctx->NewState |= NEW_RASTER_OPS;  /* to update scissor / window bounds */
 
    /* save buffer size */
-   ctx->Buffer->Width = buf_width;
-   ctx->Buffer->Height = buf_height;
+   ctx->DrawBuffer->Width = buf_width;
+   ctx->DrawBuffer->Height = buf_height;
 
    /* Reallocate other buffers if needed. */
    if (ctx->Visual->DepthBits>0) {
@@ -1959,9 +1976,9 @@ static void update_rasterflags( GLcontext *ctx )
       ctx->RasterMask |= ALPHABUF_BIT;
 
    if (   ctx->Viewport.X<0
-       || ctx->Viewport.X + ctx->Viewport.Width > ctx->Buffer->Width
+       || ctx->Viewport.X + ctx->Viewport.Width > ctx->DrawBuffer->Width
        || ctx->Viewport.Y<0
-       || ctx->Viewport.Y + ctx->Viewport.Height > ctx->Buffer->Height) {
+       || ctx->Viewport.Y + ctx->Viewport.Height > ctx->DrawBuffer->Height) {
       ctx->RasterMask |= WINCLIP_BIT;
    }
 
@@ -2144,22 +2161,22 @@ void gl_update_state( GLcontext *ctx )
 
 	 /* update scissor region */
 
-	 ctx->Buffer->Xmin = 0;
-	 ctx->Buffer->Ymin = 0;
-	 ctx->Buffer->Xmax = ctx->Buffer->Width-1;
-	 ctx->Buffer->Ymax = ctx->Buffer->Height-1;
+	 ctx->DrawBuffer->Xmin = 0;
+	 ctx->DrawBuffer->Ymin = 0;
+	 ctx->DrawBuffer->Xmax = ctx->DrawBuffer->Width-1;
+	 ctx->DrawBuffer->Ymax = ctx->DrawBuffer->Height-1;
 	 if (ctx->Scissor.Enabled) {
-	    if (ctx->Scissor.X > ctx->Buffer->Xmin) {
-	       ctx->Buffer->Xmin = ctx->Scissor.X;
+	    if (ctx->Scissor.X > ctx->DrawBuffer->Xmin) {
+	       ctx->DrawBuffer->Xmin = ctx->Scissor.X;
 	    }
-	    if (ctx->Scissor.Y > ctx->Buffer->Ymin) {
-	       ctx->Buffer->Ymin = ctx->Scissor.Y;
+	    if (ctx->Scissor.Y > ctx->DrawBuffer->Ymin) {
+	       ctx->DrawBuffer->Ymin = ctx->Scissor.Y;
 	    }
-	    if (ctx->Scissor.X + ctx->Scissor.Width - 1 < ctx->Buffer->Xmax) {
-	       ctx->Buffer->Xmax = ctx->Scissor.X + ctx->Scissor.Width - 1;
+	    if (ctx->Scissor.X + ctx->Scissor.Width - 1 < ctx->DrawBuffer->Xmax) {
+	       ctx->DrawBuffer->Xmax = ctx->Scissor.X + ctx->Scissor.Width - 1;
 	    }
-	    if (ctx->Scissor.Y + ctx->Scissor.Height - 1 < ctx->Buffer->Ymax) {
-	       ctx->Buffer->Ymax = ctx->Scissor.Y + ctx->Scissor.Height - 1;
+	    if (ctx->Scissor.Y + ctx->Scissor.Height - 1 < ctx->DrawBuffer->Ymax) {
+	       ctx->DrawBuffer->Ymax = ctx->Scissor.Y + ctx->Scissor.Height - 1;
 	    }
 	 }
 
diff --git a/src/mesa/main/context.h b/src/mesa/main/context.h
index 6d391b89d3..df510afb3f 100644
--- a/src/mesa/main/context.h
+++ b/src/mesa/main/context.h
@@ -1,4 +1,4 @@
-/* $Id: context.h,v 1.3 1999/11/19 22:26:53 brianp Exp $ */
+/* $Id: context.h,v 1.4 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -105,6 +105,9 @@ extern void gl_destroy_framebuffer( GLframebuffer *buffer );
 
 extern void gl_make_current( GLcontext *ctx, GLframebuffer *buffer );
 
+extern void gl_make_current2( GLcontext *ctx, GLframebuffer *drawBuffer,
+                              GLframebuffer *readBuffer );
+
 extern GLcontext *gl_get_current_context(void);
 
 
diff --git a/src/mesa/main/depth.c b/src/mesa/main/depth.c
index dcd84f5848..746b8188ba 100644
--- a/src/mesa/main/depth.c
+++ b/src/mesa/main/depth.c
@@ -1,4 +1,4 @@
-/* $Id: depth.c,v 1.9 1999/11/11 01:22:26 brianp Exp $ */
+/* $Id: depth.c,v 1.10 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -747,7 +747,7 @@ void gl_read_depth_span_float( GLcontext* ctx,
 
    scale = 1.0F / DEPTH_SCALE;
 
-   if (ctx->Buffer->Depth) {
+   if (ctx->DrawBuffer->Depth) {
       zptr = Z_ADDRESS( ctx, x, y );
       for (i=0;i<n;i++) {
 	 depth[i] = (GLfloat) zptr[i] * scale;
@@ -772,7 +772,7 @@ void gl_read_depth_span_float( GLcontext* ctx,
 void gl_read_depth_span_int( GLcontext* ctx,
                              GLuint n, GLint x, GLint y, GLdepth depth[] )
 {
-   if (ctx->Buffer->Depth) {
+   if (ctx->DrawBuffer->Depth) {
       GLdepth *zptr = Z_ADDRESS( ctx, x, y );
       MEMCPY( depth, zptr, n * sizeof(GLdepth) );
    }
@@ -800,16 +800,16 @@ void gl_read_depth_span_int( GLcontext* ctx,
 void gl_alloc_depth_buffer( GLcontext* ctx )
 {
    /* deallocate current depth buffer if present */
-   if (ctx->Buffer->Depth) {
-      FREE(ctx->Buffer->Depth);
-      ctx->Buffer->Depth = NULL;
+   if (ctx->DrawBuffer->Depth) {
+      FREE(ctx->DrawBuffer->Depth);
+      ctx->DrawBuffer->Depth = NULL;
    }
 
    /* allocate new depth buffer, but don't initialize it */
-   ctx->Buffer->Depth = (GLdepth *) MALLOC( ctx->Buffer->Width
-                                            * ctx->Buffer->Height
+   ctx->DrawBuffer->Depth = (GLdepth *) MALLOC( ctx->DrawBuffer->Width
+                                            * ctx->DrawBuffer->Height
                                             * sizeof(GLdepth) );
-   if (!ctx->Buffer->Depth) {
+   if (!ctx->DrawBuffer->Depth) {
       /* out of memory */
       ctx->Depth.Test = GL_FALSE;
       ctx->NewState |= NEW_RASTER_OPS;
@@ -829,7 +829,7 @@ void gl_clear_depth_buffer( GLcontext* ctx )
 {
    GLdepth clear_value = (GLdepth) (ctx->Depth.Clear * DEPTH_SCALE);
    
-   if (ctx->Visual->DepthBits==0 || !ctx->Buffer->Depth || !ctx->Depth.Mask) {
+   if (ctx->Visual->DepthBits==0 || !ctx->DrawBuffer->Depth || !ctx->Depth.Mask) {
       /* no depth buffer, or writing to it is disabled */
       return;
    }
@@ -841,9 +841,9 @@ void gl_clear_depth_buffer( GLcontext* ctx )
    if (ctx->Scissor.Enabled) {
       /* only clear scissor region */
       GLint y;
-      for (y=ctx->Buffer->Ymin; y<=ctx->Buffer->Ymax; y++) {
-         GLdepth *d = Z_ADDRESS( ctx, ctx->Buffer->Xmin, y );
-         GLint n = ctx->Buffer->Xmax - ctx->Buffer->Xmin + 1;
+      for (y=ctx->DrawBuffer->Ymin; y<=ctx->DrawBuffer->Ymax; y++) {
+         GLdepth *d = Z_ADDRESS( ctx, ctx->DrawBuffer->Xmin, y );
+         GLint n = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1;
          do {
             *d++ = clear_value;
             n--;
@@ -854,12 +854,12 @@ void gl_clear_depth_buffer( GLcontext* ctx )
       /* clear whole buffer */
       if (sizeof(GLdepth)==2 && (clear_value&0xff)==(clear_value>>8)) {
          /* lower and upper bytes of clear_value are same, use MEMSET */
-         MEMSET( ctx->Buffer->Depth, clear_value&0xff,
-                 2*ctx->Buffer->Width*ctx->Buffer->Height);
+         MEMSET( ctx->DrawBuffer->Depth, clear_value&0xff,
+                 2*ctx->DrawBuffer->Width*ctx->DrawBuffer->Height);
       }
       else {
-         GLdepth *d = ctx->Buffer->Depth;
-         GLint n = ctx->Buffer->Width * ctx->Buffer->Height;
+         GLdepth *d = ctx->DrawBuffer->Depth;
+         GLint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
          while (n>=16) {
             d[0] = clear_value;    d[1] = clear_value;
             d[2] = clear_value;    d[3] = clear_value;
diff --git a/src/mesa/main/depth.h b/src/mesa/main/depth.h
index 9749905d2c..c579e3d9fb 100644
--- a/src/mesa/main/depth.h
+++ b/src/mesa/main/depth.h
@@ -1,4 +1,4 @@
-/* $Id: depth.h,v 1.3 1999/11/11 01:22:26 brianp Exp $ */
+/* $Id: depth.h,v 1.4 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -36,7 +36,7 @@
  * Return the address of the Z-buffer value for window coordinate (x,y):
  */
 #define Z_ADDRESS( CTX, X, Y )  \
-            ((CTX)->Buffer->Depth + (CTX)->Buffer->Width * (Y) + (X))
+            ((CTX)->DrawBuffer->Depth + (CTX)->DrawBuffer->Width * (Y) + (X))
 
 
 
diff --git a/src/mesa/main/drawpix.c b/src/mesa/main/drawpix.c
index a3f1354644..60a30c2566 100644
--- a/src/mesa/main/drawpix.c
+++ b/src/mesa/main/drawpix.c
@@ -1,4 +1,4 @@
-/* $Id: drawpix.c,v 1.8 1999/11/22 22:21:38 brianp Exp $ */
+/* $Id: drawpix.c,v 1.9 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -57,28 +57,30 @@ _mesa_clip_pixelrect(const GLcontext *ctx,
                      GLsizei *width, GLsizei *height,
                      GLint *skipPixels, GLint *skipRows)
 {
+   const GLframebuffer *buffer = ctx->DrawBuffer;
+
    /* left clipping */
-   if (*destX < ctx->Buffer->Xmin) {
-      *skipPixels += (ctx->Buffer->Xmin - *destX);
-      *width -= (ctx->Buffer->Xmin - *destX);
-      *destX = ctx->Buffer->Xmin;
+   if (*destX < buffer->Xmin) {
+      *skipPixels += (buffer->Xmin - *destX);
+      *width -= (buffer->Xmin - *destX);
+      *destX = buffer->Xmin;
    }
    /* right clipping */
-   if (*destX + *width > ctx->Buffer->Xmax)
-      *width -= (*destX + *width - ctx->Buffer->Xmax - 1);
+   if (*destX + *width > buffer->Xmax)
+      *width -= (*destX + *width - buffer->Xmax - 1);
 
    if (*width <= 0)
       return GL_FALSE;
 
    /* bottom clipping */
-   if (*destY < ctx->Buffer->Ymin) {
-      *skipRows += (ctx->Buffer->Ymin - *destY);
-      *height -= (ctx->Buffer->Ymin - *destY);
-      *destY = ctx->Buffer->Ymin;
+   if (*destY < buffer->Ymin) {
+      *skipRows += (buffer->Ymin - *destY);
+      *height -= (buffer->Ymin - *destY);
+      *destY = buffer->Ymin;
    }
    /* top clipping */
-   if (*destY + *height > ctx->Buffer->Ymax)
-      *height -= (*destY + *height - ctx->Buffer->Ymax - 1);
+   if (*destY + *height > buffer->Ymax)
+      *height -= (*destY + *height - buffer->Ymax - 1);
 
    if (*height <= 0)
       return GL_TRUE;
@@ -153,24 +155,24 @@ simple_DrawPixels( GLcontext *ctx, GLint x, GLint y,
        */
       if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
          /* horizontal clipping */
-         if (destX < ctx->Buffer->Xmin) {
-            skipPixels += (ctx->Buffer->Xmin - destX);
-            drawWidth  -= (ctx->Buffer->Xmin - destX);
-            destX = ctx->Buffer->Xmin;
+         if (destX < ctx->DrawBuffer->Xmin) {
+            skipPixels += (ctx->DrawBuffer->Xmin - destX);
+            drawWidth  -= (ctx->DrawBuffer->Xmin - destX);
+            destX = ctx->DrawBuffer->Xmin;
          }
-         if (destX + drawWidth > ctx->Buffer->Xmax)
-            drawWidth -= (destX + drawWidth - ctx->Buffer->Xmax - 1);
+         if (destX + drawWidth > ctx->DrawBuffer->Xmax)
+            drawWidth -= (destX + drawWidth - ctx->DrawBuffer->Xmax - 1);
          if (drawWidth <= 0)
             return GL_TRUE;
 
          /* vertical clipping */
-         if (destY < ctx->Buffer->Ymin) {
-            skipRows   += (ctx->Buffer->Ymin - destY);
-            drawHeight -= (ctx->Buffer->Ymin - destY);
-            destY = ctx->Buffer->Ymin;
+         if (destY < ctx->DrawBuffer->Ymin) {
+            skipRows   += (ctx->DrawBuffer->Ymin - destY);
+            drawHeight -= (ctx->DrawBuffer->Ymin - destY);
+            destY = ctx->DrawBuffer->Ymin;
          }
-         if (destY + drawHeight > ctx->Buffer->Ymax)
-            drawHeight -= (destY + drawHeight - ctx->Buffer->Ymax - 1);
+         if (destY + drawHeight > ctx->DrawBuffer->Ymax)
+            drawHeight -= (destY + drawHeight - ctx->DrawBuffer->Ymax - 1);
          if (drawHeight <= 0)
             return GL_TRUE;
 
@@ -633,8 +635,8 @@ draw_rgba_pixels( GLcontext *ctx, GLint x, GLint y,
 
    if (ctx->RasterMask == 0 && !zoom
        && x >= 0 && y >= 0
-       && x + width <= ctx->Buffer->Width
-       && y + height <= ctx->Buffer->Height) {
+       && x + width <= ctx->DrawBuffer->Width
+       && y + height <= ctx->DrawBuffer->Height) {
       quickDraw = GL_TRUE;
    }
    else {
diff --git a/src/mesa/main/matrix.c b/src/mesa/main/matrix.c
index cdb8160ce5..afd33ed015 100644
--- a/src/mesa/main/matrix.c
+++ b/src/mesa/main/matrix.c
@@ -1,4 +1,4 @@
-/* $Id: matrix.c,v 1.10 1999/11/12 18:10:47 brianp Exp $ */
+/* $Id: matrix.c,v 1.11 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -1397,9 +1397,9 @@ gl_Viewport( GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height )
    ctx->RasterMask &= ~WINCLIP_BIT;
 
    if (   ctx->Viewport.X<0
-       || ctx->Viewport.X + ctx->Viewport.Width > ctx->Buffer->Width
+       || ctx->Viewport.X + ctx->Viewport.Width > ctx->DrawBuffer->Width
        || ctx->Viewport.Y<0
-       || ctx->Viewport.Y + ctx->Viewport.Height > ctx->Buffer->Height) {
+       || ctx->Viewport.Y + ctx->Viewport.Height > ctx->DrawBuffer->Height) {
       ctx->RasterMask |= WINCLIP_BIT;
    }
 
diff --git a/src/mesa/main/stencil.c b/src/mesa/main/stencil.c
index 0530700d82..df316267f6 100644
--- a/src/mesa/main/stencil.c
+++ b/src/mesa/main/stencil.c
@@ -1,4 +1,4 @@
-/* $Id: stencil.c,v 1.9 1999/11/11 01:22:27 brianp Exp $ */
+/* $Id: stencil.c,v 1.10 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -48,12 +48,6 @@
 
 
 
-/*
- * Return the address of a stencil buffer value given the window coords:
- */
-#define STENCIL_ADDRESS(X,Y)  (ctx->Buffer->Stencil + ctx->Buffer->Width * (Y) + (X))
-
-
 void
 _mesa_ClearStencil( GLint s )
 {
@@ -197,6 +191,13 @@ ENDIF
 
 
 
+/*
+ * Return the address of a stencil buffer value given the window coords:
+ */
+#define STENCIL_ADDRESS(X,Y)  \
+       (ctx->DrawBuffer->Stencil + ctx->DrawBuffer->Width * (Y) + (X))
+
+
 
 /*
  * Apply the given stencil operator for each pixel in the span whose
@@ -1006,7 +1007,7 @@ void gl_depth_stencil_pixels( GLcontext *ctx,
 void gl_read_stencil_span( GLcontext *ctx,
                            GLuint n, GLint x, GLint y, GLstencil stencil[] )
 {
-   if (ctx->Buffer->Stencil) {
+   if (ctx->DrawBuffer->Stencil) {
       const GLstencil *s = STENCIL_ADDRESS( x, y );
 #if STENCIL_BITS == 8
       MEMCPY( stencil, s, n * sizeof(GLstencil) );
@@ -1030,7 +1031,7 @@ void gl_write_stencil_span( GLcontext *ctx,
                             GLuint n, GLint x, GLint y,
 			    const GLstencil stencil[] )
 {
-   if (ctx->Buffer->Stencil) {
+   if (ctx->DrawBuffer->Stencil) {
       GLstencil *s = STENCIL_ADDRESS( x, y );
 #if STENCIL_BITS == 8
       MEMCPY( s, stencil, n * sizeof(GLstencil) );
@@ -1050,17 +1051,17 @@ void gl_write_stencil_span( GLcontext *ctx,
  */
 void gl_alloc_stencil_buffer( GLcontext *ctx )
 {
-   GLuint buffersize = ctx->Buffer->Width * ctx->Buffer->Height;
+   GLuint buffersize = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
 
    /* deallocate current stencil buffer if present */
-   if (ctx->Buffer->Stencil) {
-      FREE(ctx->Buffer->Stencil);
-      ctx->Buffer->Stencil = NULL;
+   if (ctx->DrawBuffer->Stencil) {
+      FREE(ctx->DrawBuffer->Stencil);
+      ctx->DrawBuffer->Stencil = NULL;
    }
 
    /* allocate new stencil buffer */
-   ctx->Buffer->Stencil = (GLstencil *) MALLOC(buffersize * sizeof(GLstencil));
-   if (!ctx->Buffer->Stencil) {
+   ctx->DrawBuffer->Stencil = (GLstencil *) MALLOC(buffersize * sizeof(GLstencil));
+   if (!ctx->DrawBuffer->Stencil) {
       /* out of memory */
       _mesa_set_enable( ctx, GL_STENCIL_TEST, GL_FALSE );
       gl_error( ctx, GL_OUT_OF_MEMORY, "gl_alloc_stencil_buffer" );
@@ -1076,7 +1077,7 @@ void gl_alloc_stencil_buffer( GLcontext *ctx )
  */
 void gl_clear_stencil_buffer( GLcontext *ctx )
 {
-   if (ctx->Visual->StencilBits==0 || !ctx->Buffer->Stencil) {
+   if (ctx->Visual->StencilBits==0 || !ctx->DrawBuffer->Stencil) {
       /* no stencil buffer */
       return;
    }
@@ -1084,9 +1085,9 @@ void gl_clear_stencil_buffer( GLcontext *ctx )
    if (ctx->Scissor.Enabled) {
       /* clear scissor region only */
       GLint y;
-      GLint width = ctx->Buffer->Xmax - ctx->Buffer->Xmin + 1;
-      for (y=ctx->Buffer->Ymin; y<=ctx->Buffer->Ymax; y++) {
-         GLstencil *ptr = STENCIL_ADDRESS( ctx->Buffer->Xmin, y );
+      GLint width = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1;
+      for (y=ctx->DrawBuffer->Ymin; y<=ctx->DrawBuffer->Ymax; y++) {
+         GLstencil *ptr = STENCIL_ADDRESS( ctx->DrawBuffer->Xmin, y );
 #if STENCIL_BITS==8
          MEMSET( ptr, ctx->Stencil.Clear, width * sizeof(GLstencil) );
 #else
@@ -1099,12 +1100,12 @@ void gl_clear_stencil_buffer( GLcontext *ctx )
    else {
       /* clear whole stencil buffer */
 #if STENCIL_BITS==8
-      MEMSET( ctx->Buffer->Stencil, ctx->Stencil.Clear,
-              ctx->Buffer->Width * ctx->Buffer->Height * sizeof(GLstencil) );
+      MEMSET( ctx->DrawBuffer->Stencil, ctx->Stencil.Clear,
+              ctx->DrawBuffer->Width * ctx->DrawBuffer->Height * sizeof(GLstencil) );
 #else
       GLuint i;
-      GLuint pixels = ctx->Buffer->Width * ctx->Buffer->Height;
-      GLstencil *buffer = ctx->Buffer->Stencil;
+      GLuint pixels = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
+      GLstencil *buffer = ctx->DrawBuffer->Stencil;
       for (i = 0; i < pixels; i++)
          ptr[i] = ctx->Stencil.Clear;
 #endif
diff --git a/src/mesa/main/teximage.c b/src/mesa/main/teximage.c
index 42d1c90efb..56955af6c8 100644
--- a/src/mesa/main/teximage.c
+++ b/src/mesa/main/teximage.c
@@ -1,4 +1,4 @@
-/* $Id: teximage.c,v 1.12 1999/11/11 01:22:27 brianp Exp $ */
+/* $Id: teximage.c,v 1.13 1999/11/24 18:48:31 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -1632,7 +1632,8 @@ read_color_image( GLcontext *ctx, GLint x, GLint y,
    dst = image;
    stride = width * 4 * sizeof(GLubyte);
    for (i = 0; i < height; i++) {
-      gl_read_rgba_span( ctx, width, x, y + i, (GLubyte (*)[4]) dst );
+      gl_read_rgba_span( ctx, ctx->ReadBuffer, width, x, y + i,
+                         (GLubyte (*)[4]) dst );
       dst += stride;
    }
 
@@ -1732,7 +1733,7 @@ copy_tex_sub_image( GLcontext *ctx, struct gl_texture_image *dest,
    for (i = 0;i < height; i++) {
       GLubyte rgba[MAX_WIDTH][4];
       GLubyte *dst;
-      gl_read_rgba_span( ctx, width, srcx, srcy + i, rgba );
+      gl_read_rgba_span( ctx, ctx->ReadBuffer, width, srcx, srcy + i, rgba );
       dst = dest->Data + ( zoffset + (dsty+i) * texwidth + dstx) * components;
       _mesa_unpack_ubyte_color_span(ctx, width, format, dst,
                                     GL_RGBA, GL_UNSIGNED_BYTE, rgba,