Renderbuffer adaptors.

When compiling Mesa with CHAN_BITS=16 or 32, these adaptors allow rendering
into color buffers with smaller channel sizes.

1 files changed, 628 insertions, 0 deletions

diff --git a/src/mesa/main/rbadaptors.c b/src/mesa/main/rbadaptors.c
new file mode 100644
index 00000000000..ccd021d7106
--- /dev/null
+++ b/src/mesa/main/rbadaptors.c
@@ -0,0 +1,628 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5.1
+ *
+ * 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.
+ */
+
+
+/**
+ * Renderbuffer adaptors.
+ * These fuctions are used to convert rendering from core Mesa's GLchan
+ * colors to 8 or 16-bit color channels in RGBA renderbuffers.
+ * This means Mesa can be compiled for 16 or 32-bit color processing
+ * and still render into 8 and 16-bit/channel renderbuffers.
+ */
+
+
+#include "glheader.h"
+#include "mtypes.h"
+#include "colormac.h"
+#include "renderbuffer.h"
+#include "rbadaptors.h"
+
+
+static void
+Delete_16wrap8(struct gl_renderbuffer *rb)
+{
+   rb->Wrapped->Delete(rb->Wrapped);
+   _mesa_delete_renderbuffer(rb);
+}
+
+
+static GLboolean
+AllocStorage_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb,
+                     GLenum internalFormat, GLuint width, GLuint height)
+{
+   GLboolean b = rb->Wrapped->AllocStorage(ctx, rb->Wrapped, internalFormat,
+                                           width, height);
+   if (b) {
+      rb->Width = width;
+      rb->Height = height;
+   }
+   return b;
+}
+
+
+static void *
+GetPointer_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb,
+                   GLint x, GLint y)
+{
+   (void) ctx;
+   (void) rb;
+   (void) x;
+   (void) y;
+   return NULL;
+}
+
+
+static void
+GetRow_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+               GLint x, GLint y, void *values)
+{
+   GLubyte values8[MAX_WIDTH * 4];
+   GLushort *values16 = (GLushort *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   ASSERT(count <= MAX_WIDTH);
+
+   /* get 8bpp values */
+   rb->Wrapped->GetRow(ctx, rb->Wrapped, count, x, y, values8);
+
+   /* convert 8bpp to 16bpp */
+   for (i = 0; i < 4 * count; i++) {
+      values16[i] = (values8[i] << 8) | values8[i];
+   }
+}
+
+
+static void
+GetValues_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                  const GLint x[], const GLint y[], void *values)
+{
+   GLubyte values8[MAX_WIDTH * 4];
+   GLushort *values16 = (GLushort *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+
+   rb->Wrapped->GetValues(ctx, rb->Wrapped, count, x, y, values8);
+
+   for (i = 0; i < 4 * count; i++) {
+      values16[i] = (values8[i] << 8) | values8[i];
+   }
+}
+
+
+static void
+PutRow_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+               GLint x, GLint y, const void *values, const GLubyte *mask)
+{
+   GLubyte values8[MAX_WIDTH * 4];
+   GLushort *values16 = (GLushort *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   for (i = 0; i < 4 * count; i++) {
+      values8[i] = values16[i] >> 8;
+   }
+   rb->Wrapped->PutRow(ctx, rb->Wrapped, count, x, y, values8, mask);
+}
+
+
+static void
+PutRowRGB_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                  GLint x, GLint y, const void *values, const GLubyte *mask)
+{
+   GLubyte values8[MAX_WIDTH * 3];
+   GLushort *values16 = (GLushort *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   for (i = 0; i < 3 * count; i++) {
+      values8[i] = values16[i] >> 8;
+   }
+   rb->Wrapped->PutRowRGB(ctx, rb->Wrapped, count, x, y, values8, mask);
+}
+
+
+static void
+PutMonoRow_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                   GLint x, GLint y, const void *value, const GLubyte *mask)
+{
+   GLubyte value8[4];
+   GLushort *value16 = (GLushort *) value;
+   ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   value8[0] = value16[0] >> 8;
+   value8[1] = value16[1] >> 8;
+   value8[2] = value16[2] >> 8;
+   value8[3] = value16[3] >> 8;
+   rb->Wrapped->PutMonoRow(ctx, rb->Wrapped, count, x, y, value8, mask);
+}
+
+
+static void
+PutValues_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                  const GLint x[], const GLint y[], const void *values,
+                  const GLubyte *mask)
+{
+   GLubyte values8[MAX_WIDTH * 4];
+   GLushort *values16 = (GLushort *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   for (i = 0; i < 4 * count; i++) {
+      values8[i] = values16[i] >> 8;
+   }
+   rb->Wrapped->PutValues(ctx, rb->Wrapped, count, x, y, values8, mask);
+}
+
+
+static void
+PutMonoValues_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb,
+                      GLuint count, const GLint x[], const GLint y[],
+                      const void *value, const GLubyte *mask)
+{
+   GLubyte value8[4];
+   GLushort *value16 = (GLushort *) value;
+   ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   value8[0] = value16[0] >> 8;
+   value8[1] = value16[1] >> 8;
+   value8[2] = value16[2] >> 8;
+   value8[3] = value16[3] >> 8;
+   rb->Wrapped->PutMonoValues(ctx, rb->Wrapped, count, x, y, value8, mask);
+}
+
+
+/**
+ * Wrap an 8-bit/channel renderbuffer with a 16-bit/channel
+ * renderbuffer adaptor.
+ */
+struct gl_renderbuffer *
+_mesa_new_renderbuffer_16wrap8(GLcontext *ctx, struct gl_renderbuffer *rb8)
+{
+   struct gl_renderbuffer *rb16;
+
+   rb16 = _mesa_new_renderbuffer(ctx, rb8->Name);
+   if (rb16) {
+      ASSERT(rb8->DataType == GL_UNSIGNED_BYTE);
+      ASSERT(rb8->_BaseFormat == GL_RGBA);
+
+      rb16->InternalFormat = rb8->InternalFormat;
+      rb16->_ActualFormat = rb8->_ActualFormat;
+      rb16->_BaseFormat = rb8->_BaseFormat;
+      rb16->DataType = GL_UNSIGNED_SHORT;
+      /* Note: passing through underlying bits/channel */
+      rb16->RedBits = rb8->RedBits;
+      rb16->GreenBits = rb8->GreenBits;
+      rb16->BlueBits = rb8->BlueBits;
+      rb16->AlphaBits = rb8->AlphaBits;
+      rb16->Wrapped = rb8;
+
+      rb16->AllocStorage = AllocStorage_16wrap8;
+      rb16->Delete = Delete_16wrap8;
+      rb16->GetPointer = GetPointer_16wrap8;
+      rb16->GetRow = GetRow_16wrap8;
+      rb16->GetValues = GetValues_16wrap8;
+      rb16->PutRow = PutRow_16wrap8;
+      rb16->PutRowRGB = PutRowRGB_16wrap8;
+      rb16->PutMonoRow = PutMonoRow_16wrap8;
+      rb16->PutValues = PutValues_16wrap8;
+      rb16->PutMonoValues = PutMonoValues_16wrap8;
+   }
+   return rb16;
+}
+
+
+
+
+static void
+Delete_32wrap8(struct gl_renderbuffer *rb)
+{
+   rb->Wrapped->Delete(rb->Wrapped);
+   _mesa_delete_renderbuffer(rb);
+}
+
+
+static GLboolean
+AllocStorage_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb,
+                     GLenum internalFormat, GLuint width, GLuint height)
+{
+   GLboolean b = rb->Wrapped->AllocStorage(ctx, rb->Wrapped, internalFormat,
+                                           width, height);
+   if (b) {
+      rb->Width = width;
+      rb->Height = height;
+   }
+   return b;
+}
+
+
+static void *
+GetPointer_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb,
+                   GLint x, GLint y)
+{
+   (void) ctx;
+   (void) rb;
+   (void) x;
+   (void) y;
+   return NULL;
+}
+
+
+static void
+GetRow_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+               GLint x, GLint y, void *values)
+{
+   GLubyte values8[MAX_WIDTH * 4];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   ASSERT(count <= MAX_WIDTH);
+
+   /* get 8bpp values */
+   rb->Wrapped->GetRow(ctx, rb->Wrapped, count, x, y, values8);
+
+   /* convert 8bpp to 32bpp */
+   for (i = 0; i < 4 * count; i++) {
+      values32[i] = UBYTE_TO_FLOAT(values8[i]);
+   }
+}
+
+
+static void
+GetValues_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                  const GLint x[], const GLint y[], void *values)
+{
+   GLubyte values8[MAX_WIDTH * 4];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+
+   rb->Wrapped->GetValues(ctx, rb->Wrapped, count, x, y, values8);
+
+   for (i = 0; i < 4 * count; i++) {
+      values32[i] = UBYTE_TO_FLOAT(values8[i]);
+   }
+}
+
+
+static void
+PutRow_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+               GLint x, GLint y, const void *values, const GLubyte *mask)
+{
+   GLubyte values8[MAX_WIDTH * 4];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   for (i = 0; i < 4 * count; i++) {
+      UNCLAMPED_FLOAT_TO_UBYTE(values8[i], values32[i]);
+   }
+   rb->Wrapped->PutRow(ctx, rb->Wrapped, count, x, y, values8, mask);
+}
+
+
+static void
+PutRowRGB_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                  GLint x, GLint y, const void *values, const GLubyte *mask)
+{
+   GLubyte values8[MAX_WIDTH * 3];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   for (i = 0; i < 3 * count; i++) {
+      UNCLAMPED_FLOAT_TO_UBYTE(values8[i], values32[i]);
+   }
+   rb->Wrapped->PutRowRGB(ctx, rb->Wrapped, count, x, y, values8, mask);
+}
+
+
+static void
+PutMonoRow_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                   GLint x, GLint y, const void *value, const GLubyte *mask)
+{
+   GLubyte value8[4];
+   GLfloat *value32 = (GLfloat *) value;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   UNCLAMPED_FLOAT_TO_UBYTE(value8[0], value32[0]);
+   UNCLAMPED_FLOAT_TO_UBYTE(value8[1], value32[1]);
+   UNCLAMPED_FLOAT_TO_UBYTE(value8[2], value32[2]);
+   UNCLAMPED_FLOAT_TO_UBYTE(value8[3], value32[3]);
+   rb->Wrapped->PutMonoRow(ctx, rb->Wrapped, count, x, y, value8, mask);
+}
+
+
+static void
+PutValues_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                  const GLint x[], const GLint y[], const void *values,
+                  const GLubyte *mask)
+{
+   GLubyte values8[MAX_WIDTH * 4];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   for (i = 0; i < 4 * count; i++) {
+      UNCLAMPED_FLOAT_TO_UBYTE(values8[i], values32[i]);
+   }
+   rb->Wrapped->PutValues(ctx, rb->Wrapped, count, x, y, values8, mask);
+}
+
+
+static void
+PutMonoValues_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb,
+                      GLuint count, const GLint x[], const GLint y[],
+                      const void *value, const GLubyte *mask)
+{
+   GLubyte value8[4];
+   GLfloat *value32 = (GLfloat *) value;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_BYTE);
+   UNCLAMPED_FLOAT_TO_UBYTE(value8[0], value32[0]);
+   UNCLAMPED_FLOAT_TO_UBYTE(value8[1], value32[1]);
+   UNCLAMPED_FLOAT_TO_UBYTE(value8[2], value32[2]);
+   UNCLAMPED_FLOAT_TO_UBYTE(value8[3], value32[3]);
+   rb->Wrapped->PutMonoValues(ctx, rb->Wrapped, count, x, y, value8, mask);
+}
+
+
+/**
+ * Wrap an 8-bit/channel renderbuffer with a 32-bit/channel
+ * renderbuffer adaptor.
+ */
+struct gl_renderbuffer *
+_mesa_new_renderbuffer_32wrap8(GLcontext *ctx, struct gl_renderbuffer *rb8)
+{
+   struct gl_renderbuffer *rb32;
+
+   rb32 = _mesa_new_renderbuffer(ctx, rb8->Name);
+   if (rb32) {
+      ASSERT(rb8->DataType == GL_UNSIGNED_BYTE);
+      ASSERT(rb8->_BaseFormat == GL_RGBA);
+
+      rb32->InternalFormat = rb8->InternalFormat;
+      rb32->_ActualFormat = rb8->_ActualFormat;
+      rb32->_BaseFormat = rb8->_BaseFormat;
+      rb32->DataType = GL_FLOAT;
+      /* Note: passing through underlying bits/channel */
+      rb32->RedBits = rb8->RedBits;
+      rb32->GreenBits = rb8->GreenBits;
+      rb32->BlueBits = rb8->BlueBits;
+      rb32->AlphaBits = rb8->AlphaBits;
+      rb32->Wrapped = rb8;
+
+      rb32->AllocStorage = AllocStorage_32wrap8;
+      rb32->Delete = Delete_32wrap8;
+      rb32->GetPointer = GetPointer_32wrap8;
+      rb32->GetRow = GetRow_32wrap8;
+      rb32->GetValues = GetValues_32wrap8;
+      rb32->PutRow = PutRow_32wrap8;
+      rb32->PutRowRGB = PutRowRGB_32wrap8;
+      rb32->PutMonoRow = PutMonoRow_32wrap8;
+      rb32->PutValues = PutValues_32wrap8;
+      rb32->PutMonoValues = PutMonoValues_32wrap8;
+   }
+   return rb32;
+}
+
+
+
+
+static void
+Delete_32wrap16(struct gl_renderbuffer *rb)
+{
+   rb->Wrapped->Delete(rb->Wrapped);
+   _mesa_delete_renderbuffer(rb);
+}
+
+
+static GLboolean
+AllocStorage_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb,
+                      GLenum internalFormat, GLuint width, GLuint height)
+{
+   GLboolean b = rb->Wrapped->AllocStorage(ctx, rb->Wrapped, internalFormat,
+                                           width, height);
+   if (b) {
+      rb->Width = width;
+      rb->Height = height;
+   }
+   return b;
+}
+
+
+static void *
+GetPointer_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb,
+                    GLint x, GLint y)
+{
+   (void) ctx;
+   (void) rb;
+   (void) x;
+   (void) y;
+   return NULL;
+}
+
+
+static void
+GetRow_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                GLint x, GLint y, void *values)
+{
+   GLushort values16[MAX_WIDTH * 4];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_SHORT);
+   ASSERT(count <= MAX_WIDTH);
+
+   /* get 16bpp values */
+   rb->Wrapped->GetRow(ctx, rb->Wrapped, count, x, y, values16);
+
+   /* convert 16bpp to 32bpp */
+   for (i = 0; i < 4 * count; i++) {
+      values32[i] = USHORT_TO_FLOAT(values16[i]);
+   }
+}
+
+
+static void
+GetValues_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                   const GLint x[], const GLint y[], void *values)
+{
+   GLushort values16[MAX_WIDTH * 4];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_SHORT);
+
+   rb->Wrapped->GetValues(ctx, rb->Wrapped, count, x, y, values16);
+
+   for (i = 0; i < 4 * count; i++) {
+      values32[i] = USHORT_TO_FLOAT(values16[i]);
+   }
+}
+
+
+static void
+PutRow_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                GLint x, GLint y, const void *values, const GLubyte *mask)
+{
+   GLushort values16[MAX_WIDTH * 4];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_SHORT);
+   for (i = 0; i < 4 * count; i++) {
+      UNCLAMPED_FLOAT_TO_USHORT(values16[i], values32[i]);
+   }
+   rb->Wrapped->PutRow(ctx, rb->Wrapped, count, x, y, values16, mask);
+}
+
+
+static void
+PutRowRGB_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                   GLint x, GLint y, const void *values, const GLubyte *mask)
+{
+   GLushort values16[MAX_WIDTH * 3];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_SHORT);
+   for (i = 0; i < 3 * count; i++) {
+      UNCLAMPED_FLOAT_TO_USHORT(values16[i], values32[i]);
+   }
+   rb->Wrapped->PutRowRGB(ctx, rb->Wrapped, count, x, y, values16, mask);
+}
+
+
+static void
+PutMonoRow_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                    GLint x, GLint y, const void *value, const GLubyte *mask)
+{
+   GLushort value16[4];
+   GLfloat *value32 = (GLfloat *) value;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_SHORT);
+   UNCLAMPED_FLOAT_TO_USHORT(value16[0], value32[0]);
+   UNCLAMPED_FLOAT_TO_USHORT(value16[1], value32[1]);
+   UNCLAMPED_FLOAT_TO_USHORT(value16[2], value32[2]);
+   UNCLAMPED_FLOAT_TO_USHORT(value16[3], value32[3]);
+   rb->Wrapped->PutMonoRow(ctx, rb->Wrapped, count, x, y, value16, mask);
+}
+
+
+static void
+PutValues_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint count,
+                   const GLint x[], const GLint y[], const void *values,
+                   const GLubyte *mask)
+{
+   GLushort values16[MAX_WIDTH * 4];
+   GLfloat *values32 = (GLfloat *) values;
+   GLuint i;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_SHORT);
+   for (i = 0; i < 4 * count; i++) {
+      UNCLAMPED_FLOAT_TO_USHORT(values16[i], values32[i]);
+   }
+   rb->Wrapped->PutValues(ctx, rb->Wrapped, count, x, y, values16, mask);
+}
+
+
+static void
+PutMonoValues_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb,
+                       GLuint count, const GLint x[], const GLint y[],
+                       const void *value, const GLubyte *mask)
+{
+   GLushort value16[4];
+   GLfloat *value32 = (GLfloat *) value;
+   ASSERT(rb->DataType == GL_FLOAT);
+   ASSERT(rb->Wrapped->DataType == GL_UNSIGNED_SHORT);
+   UNCLAMPED_FLOAT_TO_USHORT(value16[0], value32[0]);
+   UNCLAMPED_FLOAT_TO_USHORT(value16[1], value32[1]);
+   UNCLAMPED_FLOAT_TO_USHORT(value16[2], value32[2]);
+   UNCLAMPED_FLOAT_TO_USHORT(value16[3], value32[3]);
+   rb->Wrapped->PutMonoValues(ctx, rb->Wrapped, count, x, y, value16, mask);
+}
+
+
+/**
+ * Wrap an 16-bit/channel renderbuffer with a 32-bit/channel
+ * renderbuffer adaptor.
+ */
+struct gl_renderbuffer *
+_mesa_new_renderbuffer_32wrap16(GLcontext *ctx, struct gl_renderbuffer *rb16)
+{
+   struct gl_renderbuffer *rb32;
+
+   rb32 = _mesa_new_renderbuffer(ctx, rb16->Name);
+   if (rb32) {
+      ASSERT(rb16->DataType == GL_UNSIGNED_SHORT);
+      ASSERT(rb16->_BaseFormat == GL_RGBA);
+
+      rb32->InternalFormat = rb16->InternalFormat;
+      rb32->_ActualFormat = rb16->_ActualFormat;
+      rb32->_BaseFormat = rb16->_BaseFormat;
+      rb32->DataType = GL_FLOAT;
+      /* Note: passing through underlying bits/channel */
+      rb32->RedBits = rb16->RedBits;
+      rb32->GreenBits = rb16->GreenBits;
+      rb32->BlueBits = rb16->BlueBits;
+      rb32->AlphaBits = rb16->AlphaBits;
+      rb32->Wrapped = rb16;
+
+      rb32->AllocStorage = AllocStorage_32wrap16;
+      rb32->Delete = Delete_32wrap16;
+      rb32->GetPointer = GetPointer_32wrap16;
+      rb32->GetRow = GetRow_32wrap16;
+      rb32->GetValues = GetValues_32wrap16;
+      rb32->PutRow = PutRow_32wrap16;
+      rb32->PutRowRGB = PutRowRGB_32wrap16;
+      rb32->PutMonoRow = PutMonoRow_32wrap16;
+      rb32->PutValues = PutValues_32wrap16;
+      rb32->PutMonoValues = PutMonoValues_32wrap16;
+   }
+   return rb32;
+}