Another round of glRead/DrawBuffer() clean-ups and simplifications.

Replaced ctx->Color._DriverDrawBuffer with swrast->CurrentBuffer.
Replaced ctx->Pixel._DriverReadBuffer with ctx->Pixel._ReadSrcMask.
swrast->Driver.SetBuffer() takes FRONT/BACK_LEFT/RIGHT_BIT values now.
Added tokens and code for GL_AUX buffers, for completeness.

5 files changed, 40 insertions, 67 deletions

diff --git a/src/mesa/swrast/s_alphabuf.c b/src/mesa/swrast/s_alphabuf.c
index 2eab878a23a..4bf3368cb28 100644
--- a/src/mesa/swrast/s_alphabuf.c
+++ b/src/mesa/swrast/s_alphabuf.c
@@ -1,4 +1,4 @@
-/* $Id: s_alphabuf.c,v 1.12 2002/10/04 19:10:12 brianp Exp $ */
+/* $Id: s_alphabuf.c,v 1.13 2002/10/11 17:41:06 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -35,6 +35,7 @@
 #include "context.h"
 #include "mem.h"
 
+#include "s_context.h"
 #include "s_alphabuf.h"
 
 
@@ -171,22 +172,24 @@ _mesa_clear_alpha_buffers( GLcontext *ctx )
 static INLINE
 GLchan *get_alpha_buffer( GLcontext *ctx )
 {
-   switch (ctx->Color._DriverDrawBuffer) {
-   case GL_FRONT_LEFT:
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+
+   switch (swrast->CurrentBuffer) {
+   case FRONT_LEFT_BIT:
       return (GLchan *) ctx->DrawBuffer->FrontLeftAlpha;
       break;
-   case GL_BACK_LEFT:
+   case BACK_LEFT_BIT:
       return (GLchan *) ctx->DrawBuffer->BackLeftAlpha;
       break;
-   case GL_FRONT_RIGHT:
+   case FRONT_RIGHT_BIT:
       return (GLchan *) ctx->DrawBuffer->FrontRightAlpha;
       break;
-   case GL_BACK_RIGHT:
+   case BACK_RIGHT_BIT:
       return (GLchan *) ctx->DrawBuffer->BackRightAlpha;
       break;
    default:
-      _mesa_problem(ctx, "Bad DriverDrawBuffer in _mesa_write_alpha_span()");
-      return (GLchan *) ctx->DrawBuffer->FrontLeftAlpha; /* aribitrary */
+      _mesa_problem(ctx, "Bad CurrentBuffer in get_alpha_buffer()");
+      return (GLchan *) ctx->DrawBuffer->FrontLeftAlpha;
    }
 }
 
diff --git a/src/mesa/swrast/s_buffers.c b/src/mesa/swrast/s_buffers.c
index 1b07eb0bef0..102d53ac7fa 100644
--- a/src/mesa/swrast/s_buffers.c
+++ b/src/mesa/swrast/s_buffers.c
@@ -1,4 +1,4 @@
-/* $Id: s_buffers.c,v 1.13 2002/10/04 19:10:12 brianp Exp $ */
+/* $Id: s_buffers.c,v 1.14 2002/10/11 17:41:06 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -166,18 +166,7 @@ clear_color_buffers(GLcontext *ctx)
    /* loop over four possible dest color buffers */
    for (bufferBit = 1; bufferBit <= 8; bufferBit = bufferBit << 1) {
       if (bufferBit & ctx->Color._DrawDestMask) {
-         if (bufferBit == FRONT_LEFT_BIT) {
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_FRONT_LEFT);
-         }
-         else if (bufferBit == FRONT_RIGHT_BIT) {
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_FRONT_RIGHT);
-         }
-         else if (bufferBit == BACK_LEFT_BIT) {
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_BACK_LEFT);
-         }
-         else {
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_BACK_RIGHT);
-         }
+         (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, bufferBit);
 
          if (colorMask != 0xffffffff) {
             clear_color_buffer_with_masking(ctx);
@@ -274,10 +263,9 @@ _swrast_use_read_buffer( GLcontext *ctx )
    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 
    /* Do this so the software-emulated alpha plane span functions work! */
-   ctx->Color._DriverDrawBuffer = ctx->Pixel._DriverReadBuffer;
+   swrast->CurrentBuffer = ctx->Pixel._ReadSrcMask;
    /* Tell the device driver where to read/write spans */
-   (*swrast->Driver.SetBuffer)( ctx, ctx->ReadBuffer,
-                                ctx->Pixel._DriverReadBuffer );
+   (*swrast->Driver.SetBuffer)( ctx, ctx->ReadBuffer, swrast->CurrentBuffer );
 }
 
 
@@ -302,17 +290,16 @@ _swrast_use_draw_buffer( GLcontext *ctx )
     */
 
    if (ctx->Color._DrawDestMask & FRONT_LEFT_BIT)
-      ctx->Color._DriverDrawBuffer = GL_FRONT_LEFT;
+      swrast->CurrentBuffer = FRONT_LEFT_BIT;
    else if (ctx->Color._DrawDestMask & BACK_LEFT_BIT)
-      ctx->Color._DriverDrawBuffer = GL_BACK_LEFT;
+      swrast->CurrentBuffer = BACK_LEFT_BIT;
    else if (ctx->Color._DrawDestMask & FRONT_RIGHT_BIT)
-      ctx->Color._DriverDrawBuffer = GL_FRONT_RIGHT;
+      swrast->CurrentBuffer = FRONT_RIGHT_BIT;
    else if (ctx->Color._DrawDestMask & BACK_RIGHT_BIT)
-      ctx->Color._DriverDrawBuffer = GL_BACK_RIGHT;
+      swrast->CurrentBuffer = BACK_RIGHT_BIT;
    else
       /* glDrawBuffer(GL_NONE) */
-      ctx->Color._DriverDrawBuffer = GL_FRONT_LEFT; /* always have this */
+      swrast->CurrentBuffer = FRONT_LEFT_BIT; /* we always have this buffer */
 
-   (*swrast->Driver.SetBuffer)( ctx, ctx->DrawBuffer,
-                                ctx->Color._DriverDrawBuffer );
+   (*swrast->Driver.SetBuffer)( ctx, ctx->DrawBuffer, swrast->CurrentBuffer );
 }
diff --git a/src/mesa/swrast/s_context.h b/src/mesa/swrast/s_context.h
index ecf173adbcb..8493ad42643 100644
--- a/src/mesa/swrast/s_context.h
+++ b/src/mesa/swrast/s_context.h
@@ -1,4 +1,4 @@
-/* $Id: s_context.h,v 1.20 2002/10/04 17:37:47 brianp Exp $ */
+/* $Id: s_context.h,v 1.21 2002/10/11 17:41:06 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -138,6 +138,7 @@ typedef struct
    GLuint NewState;
    GLuint StateChanges;
    GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
+   GLuint CurrentBuffer; /* exactly one of FRONT_LEFT_BIT, BACK_LEFT_BIT, etc*/
 
    /** Mechanism to allow driver (like X11) to register further
     * software rasterization routines.
diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index b134890a3b2..2628a7af3e0 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -1,4 +1,4 @@
-/* $Id: s_span.c,v 1.48 2002/10/02 23:24:04 brianp Exp $ */
+/* $Id: s_span.c,v 1.49 2002/10/11 17:41:06 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -618,14 +618,9 @@ multi_write_index_span( GLcontext *ctx, struct sw_span *span )
          GLuint indexTmp[MAX_WIDTH];
          ASSERT(span->end < MAX_WIDTH);
 
-         if (bufferBit == FRONT_LEFT_BIT)
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_FRONT_LEFT);
-         else if (bufferBit == FRONT_RIGHT_BIT)
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_FRONT_RIGHT);
-         else if (bufferBit == BACK_LEFT_BIT)
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_BACK_LEFT);
-         else
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_BACK_RIGHT);
+         /* Set the current read/draw buffer */
+         swrast->CurrentBuffer = bufferBit;
+         (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, bufferBit);
 
          /* make copy of incoming indexes */
          MEMCPY( indexTmp, span->array->index, span->end * sizeof(GLuint) );
@@ -680,22 +675,9 @@ multi_write_rgba_span( GLcontext *ctx, struct sw_span *span )
          GLchan rgbaTmp[MAX_WIDTH][4];
          ASSERT(span->end < MAX_WIDTH);
 
-         if (bufferBit == FRONT_LEFT_BIT) {
-            ctx->Color._DriverDrawBuffer = GL_FRONT_LEFT;
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_FRONT_LEFT);
-         }
-         else if (bufferBit == FRONT_RIGHT_BIT) {
-            ctx->Color._DriverDrawBuffer = GL_FRONT_RIGHT;
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_FRONT_RIGHT);
-         }
-         else if (bufferBit == BACK_LEFT_BIT) {
-            ctx->Color._DriverDrawBuffer = GL_BACK_LEFT;
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_BACK_LEFT);
-         }
-         else {
-            ctx->Color._DriverDrawBuffer = GL_BACK_RIGHT;
-            (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, GL_BACK_RIGHT);
-         }
+         /* Set the current read/draw buffer */
+         swrast->CurrentBuffer = bufferBit;
+         (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, bufferBit);
 
          /* make copy of incoming colors */
          MEMCPY( rgbaTmp, span->array->rgba, 4 * span->end * sizeof(GLchan) );
diff --git a/src/mesa/swrast/swrast.h b/src/mesa/swrast/swrast.h
index 1cb55a9d8c8..43c9aea8dcd 100644
--- a/src/mesa/swrast/swrast.h
+++ b/src/mesa/swrast/swrast.h
@@ -1,4 +1,4 @@
-/* $Id: swrast.h,v 1.29 2002/10/04 17:37:47 brianp Exp $ */
+/* $Id: swrast.h,v 1.30 2002/10/11 17:41:06 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -390,23 +390,23 @@ _swrast_copy_texsubimage3d(GLcontext *ctx,
 
 
 
-/* The driver interface for the software rasterizer.  Unless otherwise
- * noted, all functions are mandatory.  
+/* The driver interface for the software rasterizer.
+ * Unless otherwise noted, all functions are mandatory.  
  */
 struct swrast_device_driver {
 
-   void (*SetBuffer)( GLcontext *ctx, GLframebuffer *buffer,
-                      GLenum colorBuffer );
+   void (*SetBuffer)( GLcontext *ctx, GLframebuffer *buffer, GLuint bufferBit);
    /*
     * Specifies the current buffer for span/pixel writing/reading.
     * buffer indicates which window to write to / read from.  Normally,
     * this'll be the buffer currently bound to the context, but it doesn't
     * have to be!
-    * colorBuffer indicates which color buffer, one of:
-    *    GL_FRONT_LEFT - this buffer always exists
-    *    GL_BACK_LEFT - when double buffering
-    *    GL_FRONT_RIGHT - when using stereo
-    *    GL_BACK_RIGHT - when using stereo and double buffering
+    * bufferBit indicates which color buffer, one of:
+    *    FRONT_LEFT_BIT - this buffer always exists
+    *    BACK_LEFT_BIT - when double buffering
+    *    FRONT_RIGHT_BIT - when using stereo
+    *    BACK_RIGHT_BIT - when using stereo and double buffering
+    *    AUXn_BIT - if aux buffers are implemented
     */