/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * 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.
 */

#include "main/glheader.h"
#include "main/imports.h"
#include "main/context.h"
#include "main/formats.h"
#include "main/mtypes.h"
#include "main/renderbuffer.h"
#include "swrast/s_depthstencil.h"


/**
 * Adaptor/wrappers for GL_DEPTH_STENCIL renderbuffers.
 *
 * The problem with a GL_DEPTH_STENCIL renderbuffer is that sometimes we
 * want to treat it as a stencil buffer, other times we want to treat it
 * as a depth/z buffer and still other times when we want to treat it as
 * a combined Z+stencil buffer!  That implies we need three different sets
 * of Get/Put functions.
 *
 * We solve this by wrapping the Z24_S8 or S8_Z24 renderbuffer with depth and
 * stencil adaptors, each with the right kind of depth/stencil Get/Put functions.
 */


static void *
nop_get_pointer(struct gl_context *ctx, struct gl_renderbuffer *rb, GLint x, GLint y)
{
   (void) ctx;
   (void) rb;
   (void) x;
   (void) y;
   return NULL;
}


/**
 * Delete a depth or stencil wrapper renderbuffer.
 */
static void
delete_wrapper(struct gl_renderbuffer *rb)
{
   ASSERT(rb->Format == MESA_FORMAT_S8 ||
          rb->Format == MESA_FORMAT_X8_Z24 ||
          rb->Format == MESA_FORMAT_Z32_FLOAT);
   _mesa_reference_renderbuffer(&rb->Wrapped, NULL);
   free(rb);
}


/**
 * Realloc storage for wrapper.
 */
static GLboolean
alloc_wrapper_storage(struct gl_context *ctx, struct gl_renderbuffer *rb,
                      GLenum internalFormat, GLuint width, GLuint height)
{
   /* just pass this on to the wrapped renderbuffer */
   struct gl_renderbuffer *dsrb = rb->Wrapped;
   GLboolean retVal;

   (void) internalFormat;

   ASSERT(dsrb->Format == MESA_FORMAT_Z24_S8 ||
          dsrb->Format == MESA_FORMAT_Z24_X8 ||
          dsrb->Format == MESA_FORMAT_S8_Z24 ||
          dsrb->Format == MESA_FORMAT_X8_Z24);

   retVal = dsrb->AllocStorage(ctx, dsrb, dsrb->InternalFormat, width, height);
   if (retVal) {
      rb->Width = width;
      rb->Height = height;
      rb->RowStride = dsrb->RowStride;
   }
   return retVal;
}




/*======================================================================
 * Depth wrapper around depth/stencil renderbuffer
 */

static void
get_row_z24(struct gl_context *ctx, struct gl_renderbuffer *z24rb, GLuint count,
            GLint x, GLint y, void *values)
{
   struct gl_renderbuffer *dsrb = z24rb->Wrapped;
   GLuint temp[MAX_WIDTH], i;
   GLuint *dst = (GLuint *) values;
   const GLuint *src = (const GLuint *) dsrb->GetPointer(ctx, dsrb, x, y);
   ASSERT(z24rb->DataType == GL_UNSIGNED_INT);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT);
   if (!src) {
      dsrb->GetRow(ctx, dsrb, count, x, y, temp);
      src = temp;
   }
   if (dsrb->Format == MESA_FORMAT_Z24_S8) {
      for (i = 0; i < count; i++) {
         dst[i] = src[i] >> 8;
      }
   }
   else {
      assert(dsrb->Format == MESA_FORMAT_S8_Z24);
      for (i = 0; i < count; i++) {
         dst[i] = src[i] & 0xffffff;
      }
   }
}

static void
get_values_z24(struct gl_context *ctx, struct gl_renderbuffer *z24rb, GLuint count,
               const GLint x[], const GLint y[], void *values)
{
   struct gl_renderbuffer *dsrb = z24rb->Wrapped;
   GLuint temp[MAX_WIDTH], i;
   GLuint *dst = (GLuint *) values;
   ASSERT(z24rb->DataType == GL_UNSIGNED_INT);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT);
   ASSERT(count <= MAX_WIDTH);
   /* don't bother trying direct access */
   dsrb->GetValues(ctx, dsrb, count, x, y, temp);
   if (dsrb->Format == MESA_FORMAT_Z24_S8) {
      for (i = 0; i < count; i++) {
         dst[i] = temp[i] >> 8;
      }
   }
   else {
      assert(dsrb->Format == MESA_FORMAT_S8_Z24);
      for (i = 0; i < count; i++) {
         dst[i] = temp[i] & 0xffffff;
      }
   }
}

static void
put_row_z24(struct gl_context *ctx, struct gl_renderbuffer *z24rb, GLuint count,
            GLint x, GLint y, const void *values, const GLubyte *mask)
{
   struct gl_renderbuffer *dsrb = z24rb->Wrapped;
   const GLuint *src = (const GLuint *) values;
   GLuint *dst = (GLuint *) dsrb->GetPointer(ctx, dsrb, x, y);
   ASSERT(z24rb->DataType == GL_UNSIGNED_INT);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT);
   if (dst) {
      /* direct access */
      GLuint i;
      if (dsrb->Format == MESA_FORMAT_Z24_S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               dst[i] = (src[i] << 8) | (dst[i] & 0xff);
            }
         }
      }
      else {
         assert(dsrb->Format == MESA_FORMAT_S8_Z24);
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               dst[i] = (src[i] & 0xffffff) | (dst[i] & 0xff000000);
            }
         }
      }
   }
   else {
      /* get, modify, put */
      GLuint temp[MAX_WIDTH], i;
      dsrb->GetRow(ctx, dsrb, count, x, y, temp);
      if (dsrb->Format == MESA_FORMAT_Z24_S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i] = (src[i] << 8) | (temp[i] & 0xff);
            }
         }
      }
      else {
         assert(dsrb->Format == MESA_FORMAT_S8_Z24);
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i] = (src[i] & 0xffffff) | (temp[i] & 0xff000000);
            }
         }
      }
      dsrb->PutRow(ctx, dsrb, count, x, y, temp, mask);
   }
}


static void
put_values_z24(struct gl_context *ctx, struct gl_renderbuffer *z24rb, GLuint count,
               const GLint x[], const GLint y[],
               const void *values, const GLubyte *mask)
{
   struct gl_renderbuffer *dsrb = z24rb->Wrapped;
   const GLuint *src = (const GLuint *) values;
   ASSERT(z24rb->DataType == GL_UNSIGNED_INT);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT);
   if (dsrb->GetPointer(ctx, dsrb, 0, 0)) {
      /* direct access */
      GLuint i;
      if (dsrb->Format == MESA_FORMAT_Z24_S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               GLuint *dst = (GLuint *) dsrb->GetPointer(ctx, dsrb, x[i], y[i]);
               *dst = (src[i] << 8) | (*dst & 0xff);
            }
         }
      }
      else {
         assert(dsrb->Format == MESA_FORMAT_S8_Z24);
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               GLuint *dst = (GLuint *) dsrb->GetPointer(ctx, dsrb, x[i], y[i]);
               *dst = (src[i] & 0xffffff) | (*dst & 0xff000000);
            }
         }
      }
   }
   else {
      /* get, modify, put */
      GLuint temp[MAX_WIDTH], i;
      dsrb->GetValues(ctx, dsrb, count, x, y, temp);
      if (dsrb->Format == MESA_FORMAT_Z24_S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i] = (src[i] << 8) | (temp[i] & 0xff);
            }
         }
      }
      else {
         assert(dsrb->Format == MESA_FORMAT_S8_Z24);
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i] = (src[i] & 0xffffff) | (temp[i] & 0xff000000);
            }
         }
      }
      dsrb->PutValues(ctx, dsrb, count, x, y, temp, mask);
   }
}


/**
 * Wrap the given GL_DEPTH_STENCIL renderbuffer so that it acts like
 * a depth renderbuffer.
 * \return new depth renderbuffer
 */
static struct gl_renderbuffer *
new_z24_renderbuffer_wrapper(struct gl_context *ctx,
                             struct gl_renderbuffer *dsrb)
{
   struct gl_renderbuffer *z24rb;

   ASSERT(dsrb->Format == MESA_FORMAT_Z24_S8 ||
          dsrb->Format == MESA_FORMAT_Z24_X8 ||
          dsrb->Format == MESA_FORMAT_S8_Z24 ||
          dsrb->Format == MESA_FORMAT_X8_Z24);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT);

   z24rb = ctx->Driver.NewRenderbuffer(ctx, 0);
   if (!z24rb)
      return NULL;

   /* NOTE: need to do manual refcounting here */
   z24rb->Wrapped = dsrb;
   dsrb->RefCount++;

   z24rb->Name = dsrb->Name;
   z24rb->RefCount = 0;
   z24rb->Width = dsrb->Width;
   z24rb->Height = dsrb->Height;
   z24rb->RowStride = dsrb->RowStride;
   z24rb->InternalFormat = GL_DEPTH_COMPONENT24;
   z24rb->Format = MESA_FORMAT_X8_Z24;
   z24rb->_BaseFormat = GL_DEPTH_COMPONENT;
   z24rb->DataType = GL_UNSIGNED_INT;
   z24rb->Data = NULL;
   z24rb->Delete = delete_wrapper;
   z24rb->AllocStorage = alloc_wrapper_storage;
   z24rb->GetPointer = nop_get_pointer;
   z24rb->GetRow = get_row_z24;
   z24rb->GetValues = get_values_z24;
   z24rb->PutRow = put_row_z24;
   z24rb->PutValues = put_values_z24;

   return z24rb;
}


static void
get_row_z32f(struct gl_context *ctx, struct gl_renderbuffer *z32frb, GLuint count,
             GLint x, GLint y, void *values)
{
   struct gl_renderbuffer *dsrb = z32frb->Wrapped;
   GLfloat temp[MAX_WIDTH*2];
   GLfloat *dst = (GLfloat *) values;
   const GLfloat *src = (const GLfloat *) dsrb->GetPointer(ctx, dsrb, x, y);
   GLuint i;
   ASSERT(z32frb->DataType == GL_FLOAT);
   ASSERT(dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);
   ASSERT(dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8);
   if (!src) {
      dsrb->GetRow(ctx, dsrb, count, x, y, temp);
      src = temp;
   }
   for (i = 0; i < count; i++) {
      dst[i] = src[i*2];
   }
}

static void
get_values_z32f(struct gl_context *ctx, struct gl_renderbuffer *z32frb, GLuint count,
                const GLint x[], const GLint y[], void *values)
{
   struct gl_renderbuffer *dsrb = z32frb->Wrapped;
   GLfloat temp[MAX_WIDTH*2];
   GLfloat *dst = (GLfloat *) values;
   GLuint i;
   ASSERT(z32frb->DataType == GL_FLOAT);
   ASSERT(dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);
   ASSERT(dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8);
   ASSERT(count <= MAX_WIDTH);
   /* don't bother trying direct access */
   dsrb->GetValues(ctx, dsrb, count, x, y, temp);
   for (i = 0; i < count; i++) {
      dst[i] = temp[i*2];
   }
}

static void
put_row_z32f(struct gl_context *ctx, struct gl_renderbuffer *z32frb, GLuint count,
             GLint x, GLint y, const void *values, const GLubyte *mask)
{
   struct gl_renderbuffer *dsrb = z32frb->Wrapped;
   const GLfloat *src = (const GLfloat *) values;
   GLfloat *dst = (GLfloat *) dsrb->GetPointer(ctx, dsrb, x, y);
   ASSERT(z32frb->DataType == GL_FLOAT);
   ASSERT(dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);
   ASSERT(dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8);
   if (dst) {
      /* direct access */
      GLuint i;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            dst[i*2] = src[i];
         }
      }
   }
   else {
      /* get, modify, put */
      GLfloat temp[MAX_WIDTH*2];
      GLuint i;
      dsrb->GetRow(ctx, dsrb, count, x, y, temp);
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            temp[i*2] = src[i];
         }
      }
      dsrb->PutRow(ctx, dsrb, count, x, y, temp, mask);
   }
}


static void
put_values_z32f(struct gl_context *ctx, struct gl_renderbuffer *z32frb, GLuint count,
                const GLint x[], const GLint y[],
                const void *values, const GLubyte *mask)
{
   struct gl_renderbuffer *dsrb = z32frb->Wrapped;
   const GLfloat *src = (const GLfloat *) values;
   ASSERT(z32frb->DataType == GL_FLOAT);
   ASSERT(dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);
   ASSERT(dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8);
   if (dsrb->GetPointer(ctx, dsrb, 0, 0)) {
      /* direct access */
      GLuint i;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            GLfloat *dst = (GLfloat *) dsrb->GetPointer(ctx, dsrb, x[i], y[i]);
            *dst = src[i];
         }
      }
   }
   else {
      /* get, modify, put */
      GLfloat temp[MAX_WIDTH*2];
      GLuint i;
      dsrb->GetValues(ctx, dsrb, count, x, y, temp);
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            temp[i*2] = src[i];
         }
      }
      dsrb->PutValues(ctx, dsrb, count, x, y, temp, mask);
   }
}


/**
 * Wrap the given GL_DEPTH_STENCIL renderbuffer so that it acts like
 * a depth renderbuffer.
 * \return new depth renderbuffer
 */
static struct gl_renderbuffer *
new_z32f_renderbuffer_wrapper(struct gl_context *ctx,
                              struct gl_renderbuffer *dsrb)
{
   struct gl_renderbuffer *z32frb;

   ASSERT(dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8);
   ASSERT(dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);

   z32frb = ctx->Driver.NewRenderbuffer(ctx, 0);
   if (!z32frb)
      return NULL;

   /* NOTE: need to do manual refcounting here */
   z32frb->Wrapped = dsrb;
   dsrb->RefCount++;

   z32frb->Name = dsrb->Name;
   z32frb->RefCount = 0;
   z32frb->Width = dsrb->Width;
   z32frb->Height = dsrb->Height;
   z32frb->RowStride = dsrb->RowStride;
   z32frb->InternalFormat = GL_DEPTH_COMPONENT32F;
   z32frb->Format = MESA_FORMAT_Z32_FLOAT;
   z32frb->_BaseFormat = GL_DEPTH_COMPONENT;
   z32frb->DataType = GL_FLOAT;
   z32frb->Data = NULL;
   z32frb->Delete = delete_wrapper;
   z32frb->AllocStorage = alloc_wrapper_storage;
   z32frb->GetPointer = nop_get_pointer;
   z32frb->GetRow = get_row_z32f;
   z32frb->GetValues = get_values_z32f;
   z32frb->PutRow = put_row_z32f;
   z32frb->PutValues = put_values_z32f;

   return z32frb;
}


/*======================================================================
 * Stencil wrapper around depth/stencil renderbuffer
 */

static void
get_row_s8(struct gl_context *ctx, struct gl_renderbuffer *s8rb, GLuint count,
           GLint x, GLint y, void *values)
{
   struct gl_renderbuffer *dsrb = s8rb->Wrapped;
   GLuint temp[MAX_WIDTH*2], i;
   GLubyte *dst = (GLubyte *) values;
   const GLuint *src = (const GLuint *) dsrb->GetPointer(ctx, dsrb, x, y);
   ASSERT(s8rb->DataType == GL_UNSIGNED_BYTE);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT ||
          dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);
   if (!src) {
      dsrb->GetRow(ctx, dsrb, count, x, y, temp);
      src = temp;
   }
   if (dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
      for (i = 0; i < count; i++) {
         dst[i] = src[i*2+1] & 0xff;
      }
   }
   else if (dsrb->Format == MESA_FORMAT_Z24_S8) {
      for (i = 0; i < count; i++) {
         dst[i] = src[i] & 0xff;
      }
   }
   else {
      assert(dsrb->Format == MESA_FORMAT_S8_Z24);
      for (i = 0; i < count; i++) {
         dst[i] = src[i] >> 24;
      }
   }
}

static void
get_values_s8(struct gl_context *ctx, struct gl_renderbuffer *s8rb, GLuint count,
              const GLint x[], const GLint y[], void *values)
{
   struct gl_renderbuffer *dsrb = s8rb->Wrapped;
   GLuint temp[MAX_WIDTH*2], i;
   GLubyte *dst = (GLubyte *) values;
   ASSERT(s8rb->DataType == GL_UNSIGNED_BYTE);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT ||
          dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);
   ASSERT(count <= MAX_WIDTH);
   /* don't bother trying direct access */
   dsrb->GetValues(ctx, dsrb, count, x, y, temp);
   if (dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
      for (i = 0; i < count; i++) {
         dst[i] = temp[i*2+1] & 0xff;
      }
   }
   else if (dsrb->Format == MESA_FORMAT_Z24_S8) {
      for (i = 0; i < count; i++) {
         dst[i] = temp[i] & 0xff;
      }
   }
   else {
      assert(dsrb->Format == MESA_FORMAT_S8_Z24);
      for (i = 0; i < count; i++) {
         dst[i] = temp[i] >> 24;
      }
   }
}

static void
put_row_s8(struct gl_context *ctx, struct gl_renderbuffer *s8rb, GLuint count,
           GLint x, GLint y, const void *values, const GLubyte *mask)
{
   struct gl_renderbuffer *dsrb = s8rb->Wrapped;
   const GLubyte *src = (const GLubyte *) values;
   GLuint *dst = (GLuint *) dsrb->GetPointer(ctx, dsrb, x, y);
   ASSERT(s8rb->DataType == GL_UNSIGNED_BYTE);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT ||
          dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);
   if (dst) {
      /* direct access */
      GLuint i;
      if (dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               dst[i*2+1] = src[i];
            }
         }
      }
      else if (dsrb->Format == MESA_FORMAT_Z24_S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               dst[i] = (dst[i] & 0xffffff00) | src[i];
            }
         }
      }
      else {
         assert(dsrb->Format == MESA_FORMAT_S8_Z24);
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               dst[i] = (dst[i] & 0xffffff) | (src[i] << 24);
            }
         }
      }
   }
   else {
      /* get, modify, put */
      GLuint temp[MAX_WIDTH*2], i;
      dsrb->GetRow(ctx, dsrb, count, x, y, temp);
      if (dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i*2+1] = src[i];
            }
         }
      }
      else if (dsrb->Format == MESA_FORMAT_Z24_S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i] = (temp[i] & 0xffffff00) | src[i];
            }
         }
      }
      else {
         assert(dsrb->Format == MESA_FORMAT_S8_Z24);
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i] = (temp[i] & 0xffffff) | (src[i] << 24);
            }
         }
      }
      dsrb->PutRow(ctx, dsrb, count, x, y, temp, mask);
   }
}


static void
put_values_s8(struct gl_context *ctx, struct gl_renderbuffer *s8rb, GLuint count,
              const GLint x[], const GLint y[],
              const void *values, const GLubyte *mask)
{
   struct gl_renderbuffer *dsrb = s8rb->Wrapped;
   const GLubyte *src = (const GLubyte *) values;
   ASSERT(s8rb->DataType == GL_UNSIGNED_BYTE);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT ||
          dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);
   if (dsrb->GetPointer(ctx, dsrb, 0, 0)) {
      /* direct access */
      GLuint i;
      if (dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               GLuint *dst = (GLuint *) dsrb->GetPointer(ctx, dsrb, x[i], y[i]);
               dst[1] = src[i];
            }
         }
      }
      else if (dsrb->Format == MESA_FORMAT_Z24_S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               GLuint *dst = (GLuint *) dsrb->GetPointer(ctx, dsrb, x[i], y[i]);
               *dst = (*dst & 0xffffff00) | src[i];
            }
         }
      }
      else {
         assert(dsrb->Format == MESA_FORMAT_S8_Z24);
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               GLuint *dst = (GLuint *) dsrb->GetPointer(ctx, dsrb, x[i], y[i]);
               *dst = (*dst & 0xffffff) | (src[i] << 24);
            }
         }
      }
   }
   else {
      /* get, modify, put */
      GLuint temp[MAX_WIDTH*2], i;
      dsrb->GetValues(ctx, dsrb, count, x, y, temp);
      if (dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i*2+1] = src[i];
            }
         }
      }
      else if (dsrb->Format == MESA_FORMAT_Z24_S8) {
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i] = (temp[i] & 0xffffff00) | src[i];
            }
         }
      }
      else {
         assert(dsrb->Format == MESA_FORMAT_S8_Z24);
         for (i = 0; i < count; i++) {
            if (!mask || mask[i]) {
               temp[i] = (temp[i] & 0xffffff) | (src[i] << 24);
            }
         }
      }
      dsrb->PutValues(ctx, dsrb, count, x, y, temp, mask);
   }
}


/**
 * Wrap the given GL_DEPTH_STENCIL renderbuffer so that it acts like
 * a stencil renderbuffer.
 * \return new stencil renderbuffer
 */
static struct gl_renderbuffer *
new_s8_renderbuffer_wrapper(struct gl_context *ctx, struct gl_renderbuffer *dsrb)
{
   struct gl_renderbuffer *s8rb;

   ASSERT(dsrb->Format == MESA_FORMAT_Z24_S8 ||
          dsrb->Format == MESA_FORMAT_S8_Z24 ||
          dsrb->Format == MESA_FORMAT_Z32_FLOAT_X24S8);
   ASSERT(dsrb->DataType == GL_UNSIGNED_INT_24_8_EXT ||
          dsrb->DataType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV);

   s8rb = ctx->Driver.NewRenderbuffer(ctx, 0);
   if (!s8rb)
      return NULL;

   /* NOTE: need to do manual refcounting here */
   s8rb->Wrapped = dsrb;
   dsrb->RefCount++;

   s8rb->Name = dsrb->Name;
   s8rb->RefCount = 0;
   s8rb->Width = dsrb->Width;
   s8rb->Height = dsrb->Height;
   s8rb->RowStride = dsrb->RowStride;
   s8rb->InternalFormat = GL_STENCIL_INDEX8_EXT;
   s8rb->Format = MESA_FORMAT_S8;
   s8rb->_BaseFormat = GL_STENCIL_INDEX;
   s8rb->DataType = GL_UNSIGNED_BYTE;
   s8rb->Data = NULL;
   s8rb->Delete = delete_wrapper;
   s8rb->AllocStorage = alloc_wrapper_storage;
   s8rb->GetPointer = nop_get_pointer;
   s8rb->GetRow = get_row_s8;
   s8rb->GetValues = get_values_s8;
   s8rb->PutRow = put_row_s8;
   s8rb->PutValues = put_values_s8;

   return s8rb;
}


/**
 * Update the framebuffer's _DepthBuffer field using the renderbuffer
 * found at the given attachment index.
 *
 * If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer,
 * create and install a depth wrapper/adaptor.
 *
 * \param fb  the framebuffer whose _DepthBuffer field to update
 */
void
_swrast_update_depth_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
{
   struct gl_renderbuffer *depthRb =
      fb->Attachment[BUFFER_DEPTH].Renderbuffer;

   if (depthRb && _mesa_is_format_packed_depth_stencil(depthRb->Format)) {
      /* The attached depth buffer is a GL_DEPTH_STENCIL renderbuffer */
      if (!fb->_DepthBuffer
          || fb->_DepthBuffer->Wrapped != depthRb
          || _mesa_get_format_base_format(fb->_DepthBuffer->Format) != GL_DEPTH_COMPONENT) {
         /* need to update wrapper */
         struct gl_renderbuffer *wrapper;

         if (depthRb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
            wrapper = new_z32f_renderbuffer_wrapper(ctx, depthRb);
         }
         else {
            wrapper = new_z24_renderbuffer_wrapper(ctx, depthRb);
         }
         _mesa_reference_renderbuffer(&fb->_DepthBuffer, wrapper);
      }
      ASSERT(fb->_DepthBuffer->Wrapped == depthRb);
      fb->_DepthBuffer->Width = depthRb->Width;
      fb->_DepthBuffer->Height = depthRb->Height;
   }
   else {
      /* depthRb may be null */
      _mesa_reference_renderbuffer(&fb->_DepthBuffer, depthRb);
   }
}


/**
 * Update the framebuffer's _StencilBuffer field using the renderbuffer
 * found at the given attachment index.
 *
 * If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer,
 * create and install a stencil wrapper/adaptor.
 *
 * \param fb  the framebuffer whose _StencilBuffer field to update
 */
void
_swrast_update_stencil_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
{
   struct gl_renderbuffer *stencilRb =
      fb->Attachment[BUFFER_STENCIL].Renderbuffer;

   if (stencilRb && _mesa_is_format_packed_depth_stencil(stencilRb->Format)) {
      /* The attached stencil buffer is a GL_DEPTH_STENCIL renderbuffer */
      if (!fb->_StencilBuffer
          || fb->_StencilBuffer->Wrapped != stencilRb
          || _mesa_get_format_base_format(fb->_StencilBuffer->Format) != GL_STENCIL_INDEX) {
         /* need to update wrapper */
         struct gl_renderbuffer *wrapper
            = new_s8_renderbuffer_wrapper(ctx, stencilRb);
         _mesa_reference_renderbuffer(&fb->_StencilBuffer, wrapper);
      }
      ASSERT(fb->_StencilBuffer->Wrapped == stencilRb);
      fb->_StencilBuffer->Width = stencilRb->Width;
      fb->_StencilBuffer->Height = stencilRb->Height;
   }
   else {
      /* stencilRb may be null */
      _mesa_reference_renderbuffer(&fb->_StencilBuffer, stencilRb);
   }
}