svn merge ^/branches/released .

1 files changed, 944 insertions, 0 deletions

diff --git a/mesalib/src/mesa/main/transformfeedback.c b/mesalib/src/mesa/main/transformfeedback.c
new file mode 100644
index 000000000..5c8c1fd22
--- /dev/null
+++ b/mesalib/src/mesa/main/transformfeedback.c
@@ -0,0 +1,944 @@
+/*
+ * Mesa 3-D graphics library
+ *
+ * Copyright (C) 2010  VMware, Inc.  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
+ * THE AUTHORS 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.
+ */
+
+
+/*
+ * Vertex transform feedback support.
+ *
+ * Authors:
+ *   Brian Paul
+ */
+
+
+#include "buffers.h"
+#include "bufferobj.h"
+#include "context.h"
+#include "hash.h"
+#include "transformfeedback.h"
+#include "shaderapi.h"
+#include "shaderobj.h"
+#include "main/dispatch.h"
+
+#include "program/prog_parameter.h"
+//#include "program/shader_api.h"
+
+
+#if FEATURE_EXT_transform_feedback
+
+
+/**
+ * Do reference counting of transform feedback buffers.
+ */
+static void
+reference_transform_feedback_object(struct gl_transform_feedback_object **ptr,
+                                    struct gl_transform_feedback_object *obj)
+{
+   if (*ptr == obj)
+      return;
+
+   if (*ptr) {
+      /* Unreference the old object */
+      struct gl_transform_feedback_object *oldObj = *ptr;
+
+      ASSERT(oldObj->RefCount > 0);
+      oldObj->RefCount--;
+
+      if (oldObj->RefCount == 0) {
+         GET_CURRENT_CONTEXT(ctx);
+         if (ctx)
+            ctx->Driver.DeleteTransformFeedback(ctx, oldObj);
+      }
+
+      *ptr = NULL;
+   }
+   ASSERT(!*ptr);
+
+   if (obj) {
+      /* reference new object */
+      if (obj->RefCount == 0) {
+         _mesa_problem(NULL, "referencing deleted transform feedback object");
+         *ptr = NULL;
+      }
+      else {
+         obj->RefCount++;
+         *ptr = obj;
+      }
+   }
+}
+
+
+/**
+ * Check if the given primitive mode (as in glBegin(mode)) is compatible
+ * with the current transform feedback mode (if it's enabled).
+ * This is to be called from glBegin(), glDrawArrays(), glDrawElements(), etc.
+ *
+ * \return GL_TRUE if the mode is OK, GL_FALSE otherwise.
+ */
+GLboolean
+_mesa_validate_primitive_mode(GLcontext *ctx, GLenum mode)
+{
+   if (ctx->TransformFeedback.CurrentObject->Active) {
+      switch (mode) {
+      case GL_POINTS:
+         return ctx->TransformFeedback.Mode == GL_POINTS;
+      case GL_LINES:
+      case GL_LINE_STRIP:
+      case GL_LINE_LOOP:
+         return ctx->TransformFeedback.Mode == GL_LINES;
+      default:
+         return ctx->TransformFeedback.Mode == GL_TRIANGLES;
+      }
+   }
+   return GL_TRUE;
+}
+
+
+/**
+ * Check that all the buffer objects currently bound for transform
+ * feedback actually exist.  Raise a GL_INVALID_OPERATION error if
+ * any buffers are missing.
+ * \return GL_TRUE for success, GL_FALSE if error
+ */
+GLboolean
+_mesa_validate_transform_feedback_buffers(GLcontext *ctx)
+{
+   /* XXX to do */
+   return GL_TRUE;
+}
+
+
+
+/**
+ * Per-context init for transform feedback.
+ */
+void
+_mesa_init_transform_feedback(GLcontext *ctx)
+{
+   /* core mesa expects this, even a dummy one, to be available */
+   ASSERT(ctx->Driver.NewTransformFeedback);
+
+   ctx->TransformFeedback.DefaultObject =
+      ctx->Driver.NewTransformFeedback(ctx, 0);
+
+   assert(ctx->TransformFeedback.DefaultObject->RefCount == 1);
+
+   reference_transform_feedback_object(&ctx->TransformFeedback.CurrentObject,
+                                       ctx->TransformFeedback.DefaultObject);
+
+   assert(ctx->TransformFeedback.DefaultObject->RefCount == 2);
+
+   ctx->TransformFeedback.Objects = _mesa_NewHashTable();
+
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.CurrentBuffer,
+                                 ctx->Shared->NullBufferObj);
+}
+
+
+
+/**
+ * Callback for _mesa_HashDeleteAll().
+ */
+static void
+delete_cb(GLuint key, void *data, void *userData)
+{
+   GLcontext *ctx = (GLcontext *) userData;
+   struct gl_transform_feedback_object *obj =
+      (struct gl_transform_feedback_object *) data;
+
+   ctx->Driver.DeleteTransformFeedback(ctx, obj);
+}
+
+
+/**
+ * Per-context free/clean-up for transform feedback.
+ */
+void
+_mesa_free_transform_feedback(GLcontext *ctx)
+{
+   /* core mesa expects this, even a dummy one, to be available */
+   ASSERT(ctx->Driver.NewTransformFeedback);
+
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.CurrentBuffer,
+                                 NULL);
+
+   /* Delete all feedback objects */
+   _mesa_HashDeleteAll(ctx->TransformFeedback.Objects, delete_cb, ctx);
+   _mesa_DeleteHashTable(ctx->TransformFeedback.Objects);
+
+   /* Delete the default feedback object */
+   assert(ctx->Driver.DeleteTransformFeedback);
+   ctx->Driver.DeleteTransformFeedback(ctx,
+                                       ctx->TransformFeedback.DefaultObject);
+
+   ctx->TransformFeedback.CurrentObject = NULL;
+}
+
+
+#else /* FEATURE_EXT_transform_feedback */
+
+/* forward declarations */
+static struct gl_transform_feedback_object *
+new_transform_feedback(GLcontext *ctx, GLuint name);
+
+static void
+delete_transform_feedback(GLcontext *ctx,
+                          struct gl_transform_feedback_object *obj);
+
+/* dummy per-context init/clean-up for transform feedback */
+void
+_mesa_init_transform_feedback(GLcontext *ctx)
+{
+   ctx->TransformFeedback.DefaultObject = new_transform_feedback(ctx, 0);
+   ctx->TransformFeedback.CurrentObject = ctx->TransformFeedback.DefaultObject;
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.CurrentBuffer,
+                                 ctx->Shared->NullBufferObj);
+}
+
+void
+_mesa_free_transform_feedback(GLcontext *ctx)
+{
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.CurrentBuffer,
+                                 NULL);
+   ctx->TransformFeedback.CurrentObject = NULL;
+   delete_transform_feedback(ctx, ctx->TransformFeedback.DefaultObject);
+}
+
+#endif /* FEATURE_EXT_transform_feedback */
+
+
+/** Default fallback for ctx->Driver.NewTransformFeedback() */
+static struct gl_transform_feedback_object *
+new_transform_feedback(GLcontext *ctx, GLuint name)
+{
+   struct gl_transform_feedback_object *obj;
+   obj = CALLOC_STRUCT(gl_transform_feedback_object);
+   if (obj) {
+      obj->Name = name;
+      obj->RefCount = 1;
+   }
+   return obj;
+}
+
+/** Default fallback for ctx->Driver.DeleteTransformFeedback() */
+static void
+delete_transform_feedback(GLcontext *ctx,
+                          struct gl_transform_feedback_object *obj)
+{
+   GLuint i;
+
+   for (i = 0; i < Elements(obj->Buffers); i++) {
+      _mesa_reference_buffer_object(ctx, &obj->Buffers[i], NULL);
+   }
+
+   free(obj);
+}
+
+
+#if FEATURE_EXT_transform_feedback
+
+
+/** Default fallback for ctx->Driver.BeginTransformFeedback() */
+static void
+begin_transform_feedback(GLcontext *ctx, GLenum mode,
+                         struct gl_transform_feedback_object *obj)
+{
+   /* nop */
+}
+
+/** Default fallback for ctx->Driver.EndTransformFeedback() */
+static void
+end_transform_feedback(GLcontext *ctx,
+                       struct gl_transform_feedback_object *obj)
+{
+   /* nop */
+}
+
+/** Default fallback for ctx->Driver.PauseTransformFeedback() */
+static void
+pause_transform_feedback(GLcontext *ctx,
+                         struct gl_transform_feedback_object *obj)
+{
+   /* nop */
+}
+
+/** Default fallback for ctx->Driver.ResumeTransformFeedback() */
+static void
+resume_transform_feedback(GLcontext *ctx,
+                          struct gl_transform_feedback_object *obj)
+{
+   /* nop */
+}
+
+/** Default fallback for ctx->Driver.DrawTransformFeedback() */
+static void
+draw_transform_feedback(GLcontext *ctx, GLenum mode,
+                        struct gl_transform_feedback_object *obj)
+{
+   /* XXX to do */
+   /*
+    * Get number of vertices in obj's feedback buffer.
+    * Call ctx->Exec.DrawArrays(mode, 0, count);
+    */
+}
+
+
+/**
+ * Plug in default device driver functions for transform feedback.
+ * Most drivers will override some/all of these.
+ */
+void
+_mesa_init_transform_feedback_functions(struct dd_function_table *driver)
+{
+   driver->NewTransformFeedback = new_transform_feedback;
+   driver->DeleteTransformFeedback = delete_transform_feedback;
+   driver->BeginTransformFeedback = begin_transform_feedback;
+   driver->EndTransformFeedback = end_transform_feedback;
+   driver->PauseTransformFeedback = pause_transform_feedback;
+   driver->ResumeTransformFeedback = resume_transform_feedback;
+   driver->DrawTransformFeedback = draw_transform_feedback;
+}
+
+
+void
+_mesa_init_transform_feedback_dispatch(struct _glapi_table *disp)
+{
+   SET_BeginTransformFeedbackEXT(disp, _mesa_BeginTransformFeedback);
+   SET_EndTransformFeedbackEXT(disp, _mesa_EndTransformFeedback);
+   SET_BindBufferRangeEXT(disp, _mesa_BindBufferRange);
+   SET_BindBufferBaseEXT(disp, _mesa_BindBufferBase);
+   SET_BindBufferOffsetEXT(disp, _mesa_BindBufferOffsetEXT);
+   SET_TransformFeedbackVaryingsEXT(disp, _mesa_TransformFeedbackVaryings);
+   SET_GetTransformFeedbackVaryingEXT(disp, _mesa_GetTransformFeedbackVarying);
+}
+
+
+/**
+ ** Begin API functions
+ **/
+
+
+void GLAPIENTRY
+_mesa_BeginTransformFeedback(GLenum mode)
+{
+   struct gl_transform_feedback_object *obj;
+   GET_CURRENT_CONTEXT(ctx);
+
+   obj = ctx->TransformFeedback.CurrentObject;
+
+   switch (mode) {
+   case GL_POINTS:
+   case GL_LINES:
+   case GL_TRIANGLES:
+      /* legal */
+      break;
+   default:
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBeginTransformFeedback(mode)");
+      return;
+   }
+
+   if (obj->Active) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBeginTransformFeedback(already active)");
+      return;
+   }
+
+   obj->Active = GL_TRUE;
+   ctx->TransformFeedback.Mode = mode;
+
+   assert(ctx->Driver.BeginTransformFeedback);
+   ctx->Driver.BeginTransformFeedback(ctx, mode, obj);
+}
+
+
+void GLAPIENTRY
+_mesa_EndTransformFeedback(void)
+{
+   struct gl_transform_feedback_object *obj;
+   GET_CURRENT_CONTEXT(ctx);
+
+   obj = ctx->TransformFeedback.CurrentObject;
+
+   if (!obj->Active) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glEndTransformFeedback(not active)");
+      return;
+   }
+
+   ctx->TransformFeedback.CurrentObject->Active = GL_FALSE;
+
+   assert(ctx->Driver.EndTransformFeedback);
+   ctx->Driver.EndTransformFeedback(ctx, obj);
+}
+
+
+/**
+ * Helper used by BindBufferRange() and BindBufferBase().
+ */
+static void
+bind_buffer_range(GLcontext *ctx, GLuint index,
+                  struct gl_buffer_object *bufObj,
+                  GLintptr offset, GLsizeiptr size)
+{
+   struct gl_transform_feedback_object *obj =
+      ctx->TransformFeedback.CurrentObject;
+
+   /* The general binding point */
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.CurrentBuffer,
+                                 bufObj);
+
+   /* The per-attribute binding point */
+   _mesa_reference_buffer_object(ctx,
+                                 &obj->Buffers[index],
+                                 bufObj);
+
+   obj->BufferNames[index] = bufObj->Name;
+
+   obj->Offset[index] = offset;
+   obj->Size[index] = size;
+}
+
+
+/**
+ * Specify a buffer object to receive vertex shader results.  Plus,
+ * specify the starting offset to place the results, and max size.
+ */
+void GLAPIENTRY
+_mesa_BindBufferRange(GLenum target, GLuint index,
+                      GLuint buffer, GLintptr offset, GLsizeiptr size)
+{
+   struct gl_transform_feedback_object *obj;
+   struct gl_buffer_object *bufObj;
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (target != GL_TRANSFORM_FEEDBACK_BUFFER) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferRange(target)");
+      return;
+   }
+
+   obj = ctx->TransformFeedback.CurrentObject;
+
+   if (obj->Active) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBindBufferRange(transform feedback active)");
+      return;
+   }
+
+   if (index >= ctx->Const.MaxTransformFeedbackSeparateAttribs) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glBindBufferRange(index=%d)", index);
+      return;
+   }
+
+   if ((size <= 0) || (size & 0x3)) {
+      /* must be positive and multiple of four */
+      _mesa_error(ctx, GL_INVALID_VALUE, "glBindBufferRange(size%d)", (int) size);
+      return;
+   }  
+
+   if (offset & 0x3) {
+      /* must be multiple of four */
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glBindBufferRange(offset=%d)", (int) offset);
+      return;
+   }  
+
+   bufObj = _mesa_lookup_bufferobj(ctx, buffer);
+   if (!bufObj) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBindBufferRange(invalid buffer=%u)", buffer);
+      return;
+   }
+
+   if (offset + size >= bufObj->Size) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glBindBufferRange(offset + size %d > buffer size %d)",
+		  (int) (offset + size), (int) (bufObj->Size));
+      return;
+   }  
+
+   bind_buffer_range(ctx, index, bufObj, offset, size);
+}
+
+
+/**
+ * Specify a buffer object to receive vertex shader results.
+ * As above, but start at offset = 0.
+ */
+void GLAPIENTRY
+_mesa_BindBufferBase(GLenum target, GLuint index, GLuint buffer)
+{
+   struct gl_transform_feedback_object *obj;
+   struct gl_buffer_object *bufObj;
+   GLsizeiptr size;
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (target != GL_TRANSFORM_FEEDBACK_BUFFER) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferBase(target)");
+      return;
+   }
+
+   obj = ctx->TransformFeedback.CurrentObject;
+
+   if (obj->Active) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBindBufferRange(transform feedback active)");
+      return;
+   }
+
+   if (index >= ctx->Const.MaxTransformFeedbackSeparateAttribs) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glBindBufferBase(index=%d)", index);
+      return;
+   }
+
+   bufObj = _mesa_lookup_bufferobj(ctx, buffer);
+   if (!bufObj) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBindBufferBase(invalid buffer=%u)", buffer);
+      return;
+   }
+
+   /* default size is the buffer size rounded down to nearest
+    * multiple of four.
+    */
+   size = bufObj->Size & ~0x3;
+
+   bind_buffer_range(ctx, index, bufObj, 0, size);
+}
+
+
+/**
+ * Specify a buffer object to receive vertex shader results, plus the
+ * offset in the buffer to start placing results.
+ * This function is part of GL_EXT_transform_feedback, but not GL3.
+ */
+void GLAPIENTRY
+_mesa_BindBufferOffsetEXT(GLenum target, GLuint index, GLuint buffer,
+                          GLintptr offset)
+{
+   struct gl_transform_feedback_object *obj;
+   struct gl_buffer_object *bufObj;
+   GET_CURRENT_CONTEXT(ctx);
+   GLsizeiptr size;
+
+   if (target != GL_TRANSFORM_FEEDBACK_BUFFER) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferOffsetEXT(target)");
+      return;
+   }
+
+   obj = ctx->TransformFeedback.CurrentObject;
+
+   if (obj->Active) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBindBufferRange(transform feedback active)");
+      return;
+   }
+
+   if (index >= ctx->Const.MaxTransformFeedbackSeparateAttribs) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glBindBufferOffsetEXT(index=%d)", index);
+      return;
+   }
+
+   bufObj = _mesa_lookup_bufferobj(ctx, buffer);
+   if (!bufObj) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBindBufferOffsetEXT(invalid buffer=%u)", buffer);
+      return;
+   }
+
+   /* default size is the buffer size rounded down to nearest
+    * multiple of four.
+    */
+   size = (bufObj->Size - offset) & ~0x3;
+
+   bind_buffer_range(ctx, index, bufObj, offset, size);
+}
+
+
+/**
+ * This function specifies the vertex shader outputs to be written
+ * to the feedback buffer(s), and in what order.
+ */
+void GLAPIENTRY
+_mesa_TransformFeedbackVaryings(GLuint program, GLsizei count,
+                                const GLchar **varyings, GLenum bufferMode)
+{
+   struct gl_shader_program *shProg;
+   GLuint i;
+   GET_CURRENT_CONTEXT(ctx);
+
+   switch (bufferMode) {
+   case GL_INTERLEAVED_ATTRIBS:
+      break;
+   case GL_SEPARATE_ATTRIBS:
+      break;
+   default:
+      _mesa_error(ctx, GL_INVALID_ENUM,
+                  "glTransformFeedbackVaryings(bufferMode)");
+      return;
+   }
+
+   if (count < 0 || count > ctx->Const.MaxTransformFeedbackSeparateAttribs) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glTransformFeedbackVaryings(count=%d)", count);
+      return;
+   }
+
+   shProg = _mesa_lookup_shader_program(ctx, program);
+   if (!shProg) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glTransformFeedbackVaryings(program=%u)", program);
+      return;
+   }
+
+   /* free existing varyings, if any */
+   for (i = 0; i < shProg->TransformFeedback.NumVarying; i++) {
+      free(shProg->TransformFeedback.VaryingNames[i]);
+   }
+   free(shProg->TransformFeedback.VaryingNames);
+
+   /* allocate new memory for varying names */
+   shProg->TransformFeedback.VaryingNames =
+      (GLchar **) malloc(count * sizeof(GLchar *));
+
+   if (!shProg->TransformFeedback.VaryingNames) {
+      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glTransformFeedbackVaryings()");
+      return;
+   }
+
+   /* Save the new names and the count */
+   for (i = 0; i < (GLuint) count; i++) {
+      shProg->TransformFeedback.VaryingNames[i] = _mesa_strdup(varyings[i]);
+   }
+   shProg->TransformFeedback.NumVarying = count;
+
+   shProg->TransformFeedback.BufferMode = bufferMode;
+
+   /* The varyings won't be used until shader link time */
+}
+
+
+/**
+ * Get info about the vertex shader's outputs which are to be written
+ * to the feedback buffer(s).
+ */
+void GLAPIENTRY
+_mesa_GetTransformFeedbackVarying(GLuint program, GLuint index,
+                                  GLsizei bufSize, GLsizei *length,
+                                  GLsizei *size, GLenum *type, GLchar *name)
+{
+   const struct gl_shader_program *shProg;
+   const GLchar *varyingName;
+   GLint v;
+   GET_CURRENT_CONTEXT(ctx);
+
+   shProg = _mesa_lookup_shader_program(ctx, program);
+   if (!shProg) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glGetTransformFeedbackVaryings(program=%u)", program);
+      return;
+   }
+
+   if (index >= shProg->TransformFeedback.NumVarying) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glGetTransformFeedbackVaryings(index=%u)", index);
+      return;
+   }
+
+   varyingName = shProg->TransformFeedback.VaryingNames[index];
+
+   v = _mesa_lookup_parameter_index(shProg->Varying, -1, varyingName);
+   if (v >= 0) {
+      struct gl_program_parameter *param = &shProg->Varying->Parameters[v];
+
+      /* return the varying's name and length */
+      _mesa_copy_string(name, bufSize, length, varyingName);
+
+      /* return the datatype and value's size (in datatype units) */
+      if (type)
+         *type = param->DataType;
+      if (size)
+         *size = param->Size;
+   }
+   else {
+      name[0] = 0;
+      if (length)
+         *length = 0;
+      if (type)
+         *type = 0;
+      if (size)
+         *size = 0;
+   }
+}
+
+
+
+static struct gl_transform_feedback_object *
+lookup_transform_feedback_object(GLcontext *ctx, GLuint name)
+{
+   if (name == 0) {
+      return ctx->TransformFeedback.DefaultObject;
+   }
+   else
+      return (struct gl_transform_feedback_object *)
+         _mesa_HashLookup(ctx->TransformFeedback.Objects, name);
+}
+
+
+/**
+ * Create new transform feedback objects.   Transform feedback objects
+ * encapsulate the state related to transform feedback to allow quickly
+ * switching state (and drawing the results, below).
+ * Part of GL_ARB_transform_feedback2.
+ */
+void GLAPIENTRY
+_mesa_GenTransformFeedbacks(GLsizei n, GLuint *names)
+{
+   GLuint first;
+   GET_CURRENT_CONTEXT(ctx);
+
+   ASSERT_OUTSIDE_BEGIN_END(ctx);
+
+   if (n < 0) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glGenTransformFeedbacks(n < 0)");
+      return;
+   }
+
+   if (!names)
+      return;
+
+   /* we don't need contiguous IDs, but this might be faster */
+   first = _mesa_HashFindFreeKeyBlock(ctx->TransformFeedback.Objects, n);
+   if (first) {
+      GLsizei i;
+      for (i = 0; i < n; i++) {
+         struct gl_transform_feedback_object *obj
+            = ctx->Driver.NewTransformFeedback(ctx, first + i);
+         if (!obj) {
+            _mesa_error(ctx, GL_OUT_OF_MEMORY, "glGenTransformFeedbacks");
+            return;
+         }
+         names[i] = first + i;
+         _mesa_HashInsert(ctx->TransformFeedback.Objects, first + i, obj);
+      }
+   }
+   else {
+      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glGenTransformFeedbacks");
+   }
+}
+
+
+/**
+ * Is the given ID a transform feedback object?
+ * Part of GL_ARB_transform_feedback2.
+ */
+GLboolean GLAPIENTRY
+_mesa_IsTransformFeedback(GLuint name)
+{
+   GET_CURRENT_CONTEXT(ctx);
+
+   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
+
+   if (name && lookup_transform_feedback_object(ctx, name))
+      return GL_TRUE;
+   else
+      return GL_FALSE;
+}
+
+
+/**
+ * Bind the given transform feedback object.
+ * Part of GL_ARB_transform_feedback2.
+ */
+void GLAPIENTRY
+_mesa_BindTransformFeedback(GLenum target, GLuint name)
+{
+   struct gl_transform_feedback_object *obj;
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (target != GL_TRANSFORM_FEEDBACK) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBindTransformFeedback(target)");
+      return;
+   }
+
+   if (ctx->TransformFeedback.CurrentObject->Active &&
+       !ctx->TransformFeedback.CurrentObject->Paused) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+              "glBindTransformFeedback(transform is active, or not paused)");
+      return;
+   }
+
+   obj = lookup_transform_feedback_object(ctx, name);
+   if (!obj) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBindTransformFeedback(name=%u)", name);
+      return;
+   }
+
+   reference_transform_feedback_object(&ctx->TransformFeedback.CurrentObject,
+                                       obj);
+}
+
+
+/**
+ * Delete the given transform feedback objects.
+ * Part of GL_ARB_transform_feedback2.
+ */
+void GLAPIENTRY
+_mesa_DeleteTransformFeedbacks(GLsizei n, const GLuint *names)
+{
+   GLint i;
+   GET_CURRENT_CONTEXT(ctx);
+
+   ASSERT_OUTSIDE_BEGIN_END(ctx);
+
+   if (n < 0) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glDeleteTransformFeedbacks(n < 0)");
+      return;
+   }
+
+   if (!names)
+      return;
+
+   for (i = 0; i < n; i++) {
+      if (names[i] > 0) {
+         struct gl_transform_feedback_object *obj
+            = lookup_transform_feedback_object(ctx, names[i]);
+         if (obj) {
+            if (obj->Active) {
+               _mesa_error(ctx, GL_INVALID_OPERATION,
+                           "glDeleteTransformFeedbacks(object %u is active)",
+                           names[i]);
+               return;
+            }
+            _mesa_HashRemove(ctx->TransformFeedback.Objects, names[i]);
+            /* unref, but object may not be deleted until later */
+            reference_transform_feedback_object(&obj, NULL);
+         }
+      }
+   }
+}
+
+
+/**
+ * Pause transform feedback.
+ * Part of GL_ARB_transform_feedback2.
+ */
+void GLAPIENTRY
+_mesa_PauseTransformFeedback(void)
+{
+   struct gl_transform_feedback_object *obj;
+   GET_CURRENT_CONTEXT(ctx);
+
+   obj = ctx->TransformFeedback.CurrentObject;
+
+   if (!obj->Active || obj->Paused) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+           "glPauseTransformFeedback(feedback not active or already paused)");
+      return;
+   }
+
+   obj->Paused = GL_TRUE;
+
+   assert(ctx->Driver.PauseTransformFeedback);
+   ctx->Driver.PauseTransformFeedback(ctx, obj);
+}
+
+
+/**
+ * Resume transform feedback.
+ * Part of GL_ARB_transform_feedback2.
+ */
+void GLAPIENTRY
+_mesa_ResumeTransformFeedback(void)
+{
+   struct gl_transform_feedback_object *obj;
+   GET_CURRENT_CONTEXT(ctx);
+
+   obj = ctx->TransformFeedback.CurrentObject;
+
+   if (!obj->Active || !obj->Paused) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+               "glPauseTransformFeedback(feedback not active or not paused)");
+      return;
+   }
+
+   obj->Paused = GL_FALSE;
+
+   assert(ctx->Driver.ResumeTransformFeedback);
+   ctx->Driver.ResumeTransformFeedback(ctx, obj);
+}
+
+
+/**
+ * Draw the vertex data in a transform feedback object.
+ * \param mode  GL_POINTS, GL_LINES, GL_TRIANGLE_STRIP, etc.
+ * \param name  the transform feedback object
+ * The number of vertices comes from the transform feedback object.
+ * User still has to setup of the vertex attribute info with
+ * glVertexPointer, glColorPointer, etc.
+ * Part of GL_ARB_transform_feedback2.
+ */
+void GLAPIENTRY
+_mesa_DrawTransformFeedback(GLenum mode, GLuint name)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   struct gl_transform_feedback_object *obj =
+      lookup_transform_feedback_object(ctx, name);
+
+   if (mode > GL_POLYGON) {
+      _mesa_error(ctx, GL_INVALID_ENUM,
+                  "glDrawTransformFeedback(mode=0x%x)", mode);
+      return;
+   }
+   if (!obj) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glDrawTransformFeedback(name = %u)", name);
+      return;
+   }
+
+   /* XXX check if EndTransformFeedback has never been called while
+    * the object was bound
+    */
+
+   assert(ctx->Driver.DrawTransformFeedback);
+   ctx->Driver.DrawTransformFeedback(ctx, mode, obj);
+}
+
+
+/*
+XXX misc to do:
+
+glGet*() for
+
+GL_TRANSFORM_FEEDBACK_BUFFER_PAUSED
+GL_TRANSFORM_FEEDBACK_BUFFER_ACTIVE
+GL_TRANSFORM_FEEDBACK_BINDING
+*/
+
+
+#endif /* FEATURE_EXT_transform_feedback */