svn merge ^/branches/released . --username marha

1 files changed, 965 insertions, 0 deletions

diff --git a/mesalib/src/mesa/vbo/vbo_exec_array.c b/mesalib/src/mesa/vbo/vbo_exec_array.c
new file mode 100644
index 000000000..39c295763
--- /dev/null
+++ b/mesalib/src/mesa/vbo/vbo_exec_array.c
@@ -0,0 +1,965 @@
+/**************************************************************************
+ * 
+ * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * Copyright 2009 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, sub license, 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 (including the
+ * next paragraph) 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 NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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/context.h"
+#include "main/state.h"
+#include "main/api_validate.h"
+#include "main/api_noop.h"
+#include "main/varray.h"
+#include "main/bufferobj.h"
+#include "main/macros.h"
+#include "glapi/dispatch.h"
+
+#include "vbo_context.h"
+
+
+/**
+ * Compute min and max elements for glDraw[Range]Elements() calls.
+ */
+void
+vbo_get_minmax_index(GLcontext *ctx,
+		     const struct _mesa_prim *prim,
+		     const struct _mesa_index_buffer *ib,
+		     GLuint *min_index, GLuint *max_index)
+{
+   GLuint i;
+   GLsizei count = prim->count;
+   const void *indices;
+
+   if (_mesa_is_bufferobj(ib->obj)) {
+      const GLvoid *map = ctx->Driver.MapBuffer(ctx,
+                                                GL_ELEMENT_ARRAY_BUFFER_ARB,
+                                                GL_READ_ONLY,
+                                                ib->obj);
+      indices = ADD_POINTERS(map, ib->ptr);
+   } else {
+      indices = ib->ptr;
+   }
+
+   switch (ib->type) {
+   case GL_UNSIGNED_INT: {
+      const GLuint *ui_indices = (const GLuint *)indices;
+      GLuint max_ui = ui_indices[count-1];
+      GLuint min_ui = ui_indices[0];
+      for (i = 0; i < count; i++) {
+	 if (ui_indices[i] > max_ui) max_ui = ui_indices[i];
+	 if (ui_indices[i] < min_ui) min_ui = ui_indices[i];
+      }
+      *min_index = min_ui;
+      *max_index = max_ui;
+      break;
+   }
+   case GL_UNSIGNED_SHORT: {
+      const GLushort *us_indices = (const GLushort *)indices;
+      GLuint max_us = us_indices[count-1];
+      GLuint min_us = us_indices[0];
+      for (i = 0; i < count; i++) {
+	 if (us_indices[i] > max_us) max_us = us_indices[i];
+	 if (us_indices[i] < min_us) min_us = us_indices[i];
+      }
+      *min_index = min_us;
+      *max_index = max_us;
+      break;
+   }
+   case GL_UNSIGNED_BYTE: {
+      const GLubyte *ub_indices = (const GLubyte *)indices;
+      GLuint max_ub = ub_indices[count-1];
+      GLuint min_ub = ub_indices[0];
+      for (i = 0; i < count; i++) {
+	 if (ub_indices[i] > max_ub) max_ub = ub_indices[i];
+	 if (ub_indices[i] < min_ub) min_ub = ub_indices[i];
+      }
+      *min_index = min_ub;
+      *max_index = max_ub;
+      break;
+   }
+   default:
+      assert(0);
+      break;
+   }
+
+   if (_mesa_is_bufferobj(ib->obj)) {
+      ctx->Driver.UnmapBuffer(ctx,
+			      GL_ELEMENT_ARRAY_BUFFER_ARB,
+			      ib->obj);
+   }
+}
+
+
+/**
+ * Check that element 'j' of the array has reasonable data.
+ * Map VBO if needed.
+ */
+static void
+check_array_data(GLcontext *ctx, struct gl_client_array *array,
+                 GLuint attrib, GLuint j)
+{
+   if (array->Enabled) {
+      const void *data = array->Ptr;
+      if (_mesa_is_bufferobj(array->BufferObj)) {
+         if (!array->BufferObj->Pointer) {
+            /* need to map now */
+            array->BufferObj->Pointer = ctx->Driver.MapBuffer(ctx,
+                                                              GL_ARRAY_BUFFER_ARB,
+                                                              GL_READ_ONLY,
+                                                              array->BufferObj);
+         }
+         data = ADD_POINTERS(data, array->BufferObj->Pointer);
+      }
+      switch (array->Type) {
+      case GL_FLOAT:
+         {
+            GLfloat *f = (GLfloat *) ((GLubyte *) data + array->StrideB * j);
+            GLuint k;
+            for (k = 0; k < array->Size; k++) {
+               if (IS_INF_OR_NAN(f[k]) ||
+                   f[k] >= 1.0e20 || f[k] <= -1.0e10) {
+                  _mesa_printf("Bad array data:\n");
+                  _mesa_printf("  Element[%u].%u = %f\n", j, k, f[k]);
+                  _mesa_printf("  Array %u at %p\n", attrib, (void* ) array);
+                  _mesa_printf("  Type 0x%x, Size %d, Stride %d\n",
+                               array->Type, array->Size, array->Stride);
+                  _mesa_printf("  Address/offset %p in Buffer Object %u\n",
+                               array->Ptr, array->BufferObj->Name);
+                  f[k] = 1.0; /* XXX replace the bad value! */
+               }
+               //assert(!IS_INF_OR_NAN(f[k]));
+            }
+         }
+         break;
+      default:
+         ;
+      }
+   }
+}
+
+
+/**
+ * Unmap the buffer object referenced by given array, if mapped.
+ */
+static void
+unmap_array_buffer(GLcontext *ctx, struct gl_client_array *array)
+{
+   if (array->Enabled &&
+       _mesa_is_bufferobj(array->BufferObj) &&
+       _mesa_bufferobj_mapped(array->BufferObj)) {
+      ctx->Driver.UnmapBuffer(ctx,
+                              GL_ARRAY_BUFFER_ARB,
+                              array->BufferObj);
+   }
+}
+
+
+/**
+ * Examine the array's data for NaNs, etc.
+ */
+static void
+check_draw_elements_data(GLcontext *ctx, GLsizei count, GLenum elemType,
+                         const void *elements)
+{
+   struct gl_array_object *arrayObj = ctx->Array.ArrayObj;
+   const void *elemMap;
+   GLint i, k;
+
+   if (_mesa_is_bufferobj(ctx->Array.ElementArrayBufferObj)) {
+      elemMap = ctx->Driver.MapBuffer(ctx,
+                                      GL_ELEMENT_ARRAY_BUFFER_ARB,
+                                      GL_READ_ONLY,
+                                      ctx->Array.ElementArrayBufferObj);
+      elements = ADD_POINTERS(elements, elemMap);
+   }
+
+   for (i = 0; i < count; i++) {
+      GLuint j;
+
+      /* j = element[i] */
+      switch (elemType) {
+      case GL_UNSIGNED_BYTE:
+         j = ((const GLubyte *) elements)[i];
+         break;
+      case GL_UNSIGNED_SHORT:
+         j = ((const GLushort *) elements)[i];
+         break;
+      case GL_UNSIGNED_INT:
+         j = ((const GLuint *) elements)[i];
+         break;
+      default:
+         assert(0);
+      }
+
+      /* check element j of each enabled array */
+      check_array_data(ctx, &arrayObj->Vertex, VERT_ATTRIB_POS, j);
+      check_array_data(ctx, &arrayObj->Normal, VERT_ATTRIB_NORMAL, j);
+      check_array_data(ctx, &arrayObj->Color, VERT_ATTRIB_COLOR0, j);
+      check_array_data(ctx, &arrayObj->SecondaryColor, VERT_ATTRIB_COLOR1, j);
+      for (k = 0; k < Elements(arrayObj->TexCoord); k++) {
+         check_array_data(ctx, &arrayObj->TexCoord[k], VERT_ATTRIB_TEX0 + k, j);
+      }
+      for (k = 0; k < Elements(arrayObj->VertexAttrib); k++) {
+         check_array_data(ctx, &arrayObj->VertexAttrib[k], VERT_ATTRIB_GENERIC0 + k, j);
+      }
+   }
+
+   if (_mesa_is_bufferobj(ctx->Array.ElementArrayBufferObj)) {
+      ctx->Driver.UnmapBuffer(ctx,
+			      GL_ELEMENT_ARRAY_BUFFER_ARB,
+			      ctx->Array.ElementArrayBufferObj);
+   }
+
+   unmap_array_buffer(ctx, &arrayObj->Vertex);
+   unmap_array_buffer(ctx, &arrayObj->Normal);
+   unmap_array_buffer(ctx, &arrayObj->Color);
+   for (k = 0; k < Elements(arrayObj->TexCoord); k++) {
+      unmap_array_buffer(ctx, &arrayObj->TexCoord[k]);
+   }
+   for (k = 0; k < Elements(arrayObj->VertexAttrib); k++) {
+      unmap_array_buffer(ctx, &arrayObj->VertexAttrib[k]);
+   }
+}
+
+
+/**
+ * Check array data, looking for NaNs, etc.
+ */
+static void
+check_draw_arrays_data(GLcontext *ctx, GLint start, GLsizei count)
+{
+   /* TO DO */
+}
+
+
+/**
+ * Print info/data for glDrawArrays().
+ */
+static void
+print_draw_arrays(GLcontext *ctx, struct vbo_exec_context *exec,
+                  GLenum mode, GLint start, GLsizei count)
+{
+   int i;
+
+   _mesa_printf("vbo_exec_DrawArrays(mode 0x%x, start %d, count %d):\n",
+                mode, start, count);
+
+   for (i = 0; i < 32; i++) {
+      GLuint bufName = exec->array.inputs[i]->BufferObj->Name;
+      GLint stride = exec->array.inputs[i]->Stride;
+      _mesa_printf("attr %2d: size %d stride %d  enabled %d  "
+                   "ptr %p  Bufobj %u\n",
+                   i,
+                   exec->array.inputs[i]->Size,
+                   stride,
+                   /*exec->array.inputs[i]->Enabled,*/
+                   exec->array.legacy_array[i]->Enabled,
+                   exec->array.inputs[i]->Ptr,
+                   bufName);
+
+      if (bufName) {
+         struct gl_buffer_object *buf = _mesa_lookup_bufferobj(ctx, bufName);
+         GLubyte *p = ctx->Driver.MapBuffer(ctx, GL_ARRAY_BUFFER_ARB,
+                                            GL_READ_ONLY_ARB, buf);
+         int offset = (int) (GLintptr) exec->array.inputs[i]->Ptr;
+         float *f = (float *) (p + offset);
+         int *k = (int *) f;
+         int i;
+         int n = (count * stride) / 4;
+         if (n > 32)
+            n = 32;
+         _mesa_printf("  Data at offset %d:\n", offset);
+         for (i = 0; i < n; i++) {
+            _mesa_printf("    float[%d] = 0x%08x %f\n", i, k[i], f[i]);
+         }
+         ctx->Driver.UnmapBuffer(ctx, GL_ARRAY_BUFFER_ARB, buf);
+      }
+   }
+}
+
+
+/**
+ * Just translate the arrayobj into a sane layout.
+ */
+static void
+bind_array_obj(GLcontext *ctx)
+{
+   struct vbo_context *vbo = vbo_context(ctx);
+   struct vbo_exec_context *exec = &vbo->exec;
+   struct gl_array_object *arrayObj = ctx->Array.ArrayObj;
+   GLuint i;
+
+   /* TODO: Fix the ArrayObj struct to keep legacy arrays in an array
+    * rather than as individual named arrays.  Then this function can
+    * go away.
+    */
+   exec->array.legacy_array[VERT_ATTRIB_POS] = &arrayObj->Vertex;
+   exec->array.legacy_array[VERT_ATTRIB_WEIGHT] = &arrayObj->Weight;
+   exec->array.legacy_array[VERT_ATTRIB_NORMAL] = &arrayObj->Normal;
+   exec->array.legacy_array[VERT_ATTRIB_COLOR0] = &arrayObj->Color;
+   exec->array.legacy_array[VERT_ATTRIB_COLOR1] = &arrayObj->SecondaryColor;
+   exec->array.legacy_array[VERT_ATTRIB_FOG] = &arrayObj->FogCoord;
+   exec->array.legacy_array[VERT_ATTRIB_COLOR_INDEX] = &arrayObj->Index;
+   if (arrayObj->PointSize.Enabled) {
+      /* this aliases COLOR_INDEX */
+      exec->array.legacy_array[VERT_ATTRIB_POINT_SIZE] = &arrayObj->PointSize;
+   }
+   exec->array.legacy_array[VERT_ATTRIB_EDGEFLAG] = &arrayObj->EdgeFlag;
+
+   for (i = 0; i < Elements(arrayObj->TexCoord); i++)
+      exec->array.legacy_array[VERT_ATTRIB_TEX0 + i] = &arrayObj->TexCoord[i];
+
+   for (i = 0; i < Elements(arrayObj->VertexAttrib); i++) {
+      assert(i < Elements(exec->array.generic_array));
+      exec->array.generic_array[i] = &arrayObj->VertexAttrib[i];
+   }
+   
+   exec->array.array_obj = arrayObj->Name;
+}
+
+
+static void
+recalculate_input_bindings(GLcontext *ctx)
+{
+   struct vbo_context *vbo = vbo_context(ctx);
+   struct vbo_exec_context *exec = &vbo->exec;
+   const struct gl_client_array **inputs = &exec->array.inputs[0];
+   GLbitfield const_inputs = 0x0;
+   GLuint i;
+
+   exec->array.program_mode = get_program_mode(ctx);
+   exec->array.enabled_flags = ctx->Array.ArrayObj->_Enabled;
+
+   switch (exec->array.program_mode) {
+   case VP_NONE:
+      /* When no vertex program is active (or the vertex program is generated
+       * from fixed-function state).  We put the material values into the
+       * generic slots.  This is the only situation where material values
+       * are available as per-vertex attributes.
+       */
+      for (i = 0; i <= VERT_ATTRIB_TEX7; i++) {
+	 if (exec->array.legacy_array[i]->Enabled)
+	    inputs[i] = exec->array.legacy_array[i];
+	 else {
+	    inputs[i] = &vbo->legacy_currval[i];
+            const_inputs |= 1 << i;
+         }
+      }
+
+      for (i = 0; i < MAT_ATTRIB_MAX; i++) {
+	 inputs[VERT_ATTRIB_GENERIC0 + i] = &vbo->mat_currval[i];
+         const_inputs |= 1 << (VERT_ATTRIB_GENERIC0 + i);
+      }
+
+      /* Could use just about anything, just to fill in the empty
+       * slots:
+       */
+      for (i = MAT_ATTRIB_MAX; i < VERT_ATTRIB_MAX - VERT_ATTRIB_GENERIC0; i++) {
+	 inputs[VERT_ATTRIB_GENERIC0 + i] = &vbo->generic_currval[i];
+         const_inputs |= 1 << (VERT_ATTRIB_GENERIC0 + i);
+      }
+      break;
+
+   case VP_NV:
+      /* NV_vertex_program - attribute arrays alias and override
+       * conventional, legacy arrays.  No materials, and the generic
+       * slots are vacant.
+       */
+      for (i = 0; i <= VERT_ATTRIB_TEX7; i++) {
+	 if (exec->array.generic_array[i]->Enabled)
+	    inputs[i] = exec->array.generic_array[i];
+	 else if (exec->array.legacy_array[i]->Enabled)
+	    inputs[i] = exec->array.legacy_array[i];
+	 else {
+	    inputs[i] = &vbo->legacy_currval[i];
+            const_inputs |= 1 << i;
+         }
+      }
+
+      /* Could use just about anything, just to fill in the empty
+       * slots:
+       */
+      for (i = VERT_ATTRIB_GENERIC0; i < VERT_ATTRIB_MAX; i++) {
+	 inputs[i] = &vbo->generic_currval[i - VERT_ATTRIB_GENERIC0];
+         const_inputs |= 1 << i;
+      }
+      break;
+
+   case VP_ARB:
+      /* GL_ARB_vertex_program or GLSL vertex shader - Only the generic[0]
+       * attribute array aliases and overrides the legacy position array.  
+       *
+       * Otherwise, legacy attributes available in the legacy slots,
+       * generic attributes in the generic slots and materials are not
+       * available as per-vertex attributes.
+       */
+      if (exec->array.generic_array[0]->Enabled)
+	 inputs[0] = exec->array.generic_array[0];
+      else if (exec->array.legacy_array[0]->Enabled)
+	 inputs[0] = exec->array.legacy_array[0];
+      else {
+	 inputs[0] = &vbo->legacy_currval[0];
+         const_inputs |= 1 << 0;
+      }
+
+      for (i = 1; i <= VERT_ATTRIB_TEX7; i++) {
+	 if (exec->array.legacy_array[i]->Enabled)
+	    inputs[i] = exec->array.legacy_array[i];
+	 else {
+	    inputs[i] = &vbo->legacy_currval[i];
+            const_inputs |= 1 << i;
+         }
+      }
+
+      for (i = 0; i < MAX_VERTEX_GENERIC_ATTRIBS; i++) {
+	 if (exec->array.generic_array[i]->Enabled)
+	    inputs[VERT_ATTRIB_GENERIC0 + i] = exec->array.generic_array[i];
+	 else {
+	    inputs[VERT_ATTRIB_GENERIC0 + i] = &vbo->generic_currval[i];
+            const_inputs |= 1 << (VERT_ATTRIB_GENERIC0 + i);
+         }
+
+      }
+      break;
+   }
+
+   _mesa_set_varying_vp_inputs( ctx, ~const_inputs );
+}
+
+
+static void
+bind_arrays(GLcontext *ctx)
+{
+#if 0
+   if (ctx->Array.ArrayObj.Name != exec->array.array_obj) {
+      bind_array_obj(ctx);
+      recalculate_input_bindings(ctx);
+   }
+   else if (exec->array.program_mode != get_program_mode(ctx) ||
+	    exec->array.enabled_flags != ctx->Array.ArrayObj->_Enabled) {
+      
+      recalculate_input_bindings(ctx);
+   }
+#else
+   bind_array_obj(ctx);
+   recalculate_input_bindings(ctx);
+#endif
+}
+
+
+
+/***********************************************************************
+ * API functions.
+ */
+
+static void GLAPIENTRY
+vbo_exec_DrawArrays(GLenum mode, GLint start, GLsizei count)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   struct vbo_context *vbo = vbo_context(ctx);
+   struct vbo_exec_context *exec = &vbo->exec;
+   struct _mesa_prim prim[1];
+
+   if (!_mesa_validate_DrawArrays( ctx, mode, start, count ))
+      return;
+
+   FLUSH_CURRENT( ctx, 0 );
+
+   if (ctx->NewState)
+      _mesa_update_state( ctx );
+      
+   if (!_mesa_valid_to_render(ctx, "glDrawArrays")) {
+      return;
+   }
+
+#if 0
+   check_draw_arrays_data(ctx, start, count);
+#else
+   (void) check_draw_arrays_data;
+#endif
+
+   bind_arrays( ctx );
+
+   /* Again... because we may have changed the bitmask of per-vertex varying
+    * attributes.  If we regenerate the fixed-function vertex program now
+    * we may be able to prune down the number of vertex attributes which we
+    * need in the shader.
+    */
+   if (ctx->NewState)
+      _mesa_update_state( ctx );
+
+   prim[0].begin = 1;
+   prim[0].end = 1;
+   prim[0].weak = 0;
+   prim[0].pad = 0;
+   prim[0].mode = mode;
+   prim[0].start = start;
+   prim[0].count = count;
+   prim[0].indexed = 0;
+
+   vbo->draw_prims( ctx, exec->array.inputs, prim, 1, NULL,
+                    GL_TRUE, start, start + count - 1 );
+
+#if 0
+   print_draw_arrays(ctx, exec, mode, start, count);
+#else
+   (void) print_draw_arrays;
+#endif
+}
+
+
+/**
+ * Map GL_ELEMENT_ARRAY_BUFFER and print contents.
+ */
+static void
+dump_element_buffer(GLcontext *ctx, GLenum type)
+{
+   const GLvoid *map = ctx->Driver.MapBuffer(ctx,
+                                             GL_ELEMENT_ARRAY_BUFFER_ARB,
+                                             GL_READ_ONLY,
+                                             ctx->Array.ElementArrayBufferObj);
+   switch (type) {
+   case GL_UNSIGNED_BYTE:
+      {
+         const GLubyte *us = (const GLubyte *) map;
+         GLuint i;
+         for (i = 0; i < ctx->Array.ElementArrayBufferObj->Size; i++) {
+            _mesa_printf("%02x ", us[i]);
+            if (i % 32 == 31)
+               _mesa_printf("\n");
+         }
+         _mesa_printf("\n");
+      }
+      break;
+   case GL_UNSIGNED_SHORT:
+      {
+         const GLushort *us = (const GLushort *) map;
+         GLuint i;
+         for (i = 0; i < ctx->Array.ElementArrayBufferObj->Size / 2; i++) {
+            _mesa_printf("%04x ", us[i]);
+            if (i % 16 == 15)
+               _mesa_printf("\n");
+         }
+         _mesa_printf("\n");
+      }
+      break;
+   case GL_UNSIGNED_INT:
+      {
+         const GLuint *us = (const GLuint *) map;
+         GLuint i;
+         for (i = 0; i < ctx->Array.ElementArrayBufferObj->Size / 4; i++) {
+            _mesa_printf("%08x ", us[i]);
+            if (i % 8 == 7)
+               _mesa_printf("\n");
+         }
+         _mesa_printf("\n");
+      }
+      break;
+   default:
+      ;
+   }
+
+   ctx->Driver.UnmapBuffer(ctx,
+                           GL_ELEMENT_ARRAY_BUFFER_ARB,
+                           ctx->Array.ElementArrayBufferObj);
+}
+
+/* Inner support for both _mesa_DrawElements and _mesa_DrawRangeElements */
+static void
+vbo_validated_drawrangeelements(GLcontext *ctx, GLenum mode,
+				GLboolean index_bounds_valid,
+				GLuint start, GLuint end,
+				GLsizei count, GLenum type,
+				const GLvoid *indices)
+{
+   struct vbo_context *vbo = vbo_context(ctx);
+   struct vbo_exec_context *exec = &vbo->exec;
+   struct _mesa_index_buffer ib;
+   struct _mesa_prim prim[1];
+
+   FLUSH_CURRENT( ctx, 0 );
+
+   if (ctx->NewState)
+      _mesa_update_state( ctx );
+
+   if (!_mesa_valid_to_render(ctx, "glDraw[Range]Elements")) {
+      return;
+   }
+
+   if (ctx->NewState)
+      _mesa_update_state( ctx );
+
+   bind_arrays( ctx );
+
+   ib.count = count;
+   ib.type = type;
+   ib.obj = ctx->Array.ElementArrayBufferObj;
+   ib.ptr = indices;
+
+   prim[0].begin = 1;
+   prim[0].end = 1;
+   prim[0].weak = 0;
+   prim[0].pad = 0;
+   prim[0].mode = mode;
+   prim[0].start = 0;
+   prim[0].count = count;
+   prim[0].indexed = 1;
+
+   /* Need to give special consideration to rendering a range of
+    * indices starting somewhere above zero.  Typically the
+    * application is issuing multiple DrawRangeElements() to draw
+    * successive primitives layed out linearly in the vertex arrays.
+    * Unless the vertex arrays are all in a VBO (or locked as with
+    * CVA), the OpenGL semantics imply that we need to re-read or
+    * re-upload the vertex data on each draw call.  
+    *
+    * In the case of hardware tnl, we want to avoid starting the
+    * upload at zero, as it will mean every draw call uploads an
+    * increasing amount of not-used vertex data.  Worse - in the
+    * software tnl module, all those vertices might be transformed and
+    * lit but never rendered.
+    *
+    * If we just upload or transform the vertices in start..end,
+    * however, the indices will be incorrect.
+    *
+    * At this level, we don't know exactly what the requirements of
+    * the backend are going to be, though it will likely boil down to
+    * either:
+    *
+    * 1) Do nothing, everything is in a VBO and is processed once
+    *       only.
+    *
+    * 2) Adjust the indices and vertex arrays so that start becomes
+    *    zero.
+    *
+    * Rather than doing anything here, I'll provide a helper function
+    * for the latter case elsewhere.
+    */
+
+   vbo->draw_prims( ctx, exec->array.inputs, prim, 1, &ib,
+		    index_bounds_valid, start, end );
+}
+
+static void GLAPIENTRY
+vbo_exec_DrawRangeElements(GLenum mode,
+			   GLuint start, GLuint end,
+			   GLsizei count, GLenum type, const GLvoid *indices)
+{
+   static GLuint warnCount = 0;
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (!_mesa_validate_DrawRangeElements( ctx, mode, start, end, count,
+                                          type, indices ))
+      return;
+
+   if (end >= ctx->Array.ArrayObj->_MaxElement) {
+      /* the max element is out of bounds of one or more enabled arrays */
+      warnCount++;
+
+      if (warnCount < 10) {
+         _mesa_warning(ctx, "glDraw[Range]Elements(start %u, end %u, count %d, "
+                       "type 0x%x, indices=%p)\n"
+                       "\tend is out of bounds (max=%u)  "
+                       "Element Buffer %u (size %d)\n"
+                       "\tThis should probably be fixed in the application.",
+                       start, end, count, type, indices,
+                       ctx->Array.ArrayObj->_MaxElement - 1,
+                       ctx->Array.ElementArrayBufferObj->Name,
+                       ctx->Array.ElementArrayBufferObj->Size);
+      }
+
+      if (0)
+         dump_element_buffer(ctx, type);
+
+      if (0)
+         _mesa_print_arrays(ctx);
+
+#ifdef DEBUG
+      /* 'end' was out of bounds, but now let's check the actual array
+       * indexes to see if any of them are out of bounds.  If so, warn
+       * and skip the draw to avoid potential segfault, etc.
+       */
+      {
+         GLuint max = _mesa_max_buffer_index(ctx, count, type, indices,
+                                             ctx->Array.ElementArrayBufferObj);
+         if (max >= ctx->Array.ArrayObj->_MaxElement) {
+            if (warnCount < 10) {
+               _mesa_warning(ctx, "glDraw[Range]Elements(start %u, end %u, "
+                             "count %d, type 0x%x, indices=%p)\n"
+                             "\tindex=%u is out of bounds (max=%u)  "
+                             "Element Buffer %u (size %d)\n"
+                             "\tSkipping the glDrawRangeElements() call",
+                             start, end, count, type, indices, max,
+                             ctx->Array.ArrayObj->_MaxElement - 1,
+                             ctx->Array.ElementArrayBufferObj->Name,
+                             ctx->Array.ElementArrayBufferObj->Size);
+            }
+            return;
+         }
+         /* XXX we could also find the min index and compare to 'start'
+          * to see if start is correct.  But it's more likely to get the
+          * upper bound wrong.
+          */
+      }
+#endif
+   }
+   else if (0) {
+      _mesa_printf("glDraw[Range]Elements"
+                   "(start %u, end %u, type 0x%x, count %d) ElemBuf %u\n",
+                   start, end, type, count,
+                   ctx->Array.ElementArrayBufferObj->Name);
+   }
+
+#if 0
+   check_draw_elements_data(ctx, count, type, indices);
+#else
+   (void) check_draw_elements_data;
+#endif
+
+   vbo_validated_drawrangeelements(ctx, mode, GL_TRUE, start, end,
+				   count, type, indices);
+}
+
+
+static void GLAPIENTRY
+vbo_exec_DrawElements(GLenum mode, GLsizei count, GLenum type,
+                      const GLvoid *indices)
+{
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (!_mesa_validate_DrawElements( ctx, mode, count, type, indices ))
+      return;
+
+   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, ~0, ~0,
+				   count, type, indices);
+}
+
+/* Inner support for both _mesa_DrawElements and _mesa_DrawRangeElements */
+static void
+vbo_validated_multidrawelements(GLcontext *ctx, GLenum mode,
+				const GLsizei *count, GLenum type,
+				const GLvoid **indices, GLsizei primcount)
+{
+   struct vbo_context *vbo = vbo_context(ctx);
+   struct vbo_exec_context *exec = &vbo->exec;
+   struct _mesa_index_buffer ib;
+   struct _mesa_prim *prim;
+   unsigned int index_type_size = 0;
+   uintptr_t min_index_ptr, max_index_ptr;
+   GLboolean fallback = GL_FALSE;
+   int i;
+
+   if (primcount == 0)
+      return;
+
+   FLUSH_CURRENT( ctx, 0 );
+
+   if (ctx->NewState)
+      _mesa_update_state( ctx );
+
+   if (!_mesa_valid_to_render(ctx, "glMultiDrawElements")) {
+      return;
+   }
+
+   if (ctx->NewState)
+      _mesa_update_state( ctx );
+
+   prim = _mesa_calloc(primcount * sizeof(*prim));
+   if (prim == NULL) {
+      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glMultiDrawElements");
+      return;
+   }
+
+   /* Decide if we can do this all as one set of primitives sharing the
+    * same index buffer, or if we have to reset the index pointer per primitive.
+    */
+   bind_arrays( ctx );
+
+   switch (type) {
+   case GL_UNSIGNED_INT:
+      index_type_size = 4;
+      break;
+   case GL_UNSIGNED_SHORT:
+      index_type_size = 2;
+      break;
+   case GL_UNSIGNED_BYTE:
+      index_type_size = 1;
+      break;
+   default:
+      assert(0);
+   }
+
+   min_index_ptr = (uintptr_t)indices[0];
+   max_index_ptr = 0;
+   for (i = 0; i < primcount; i++) {
+      min_index_ptr = MIN2(min_index_ptr, (uintptr_t)indices[i]);
+      max_index_ptr = MAX2(max_index_ptr, (uintptr_t)indices[i] +
+			   index_type_size * count[i]);
+   }
+
+   /* Check if we can handle this thing as a bunch of index offsets from the
+    * same index pointer.  If we can't, then we have to fall back to doing
+    * a draw_prims per primitive.
+    */
+   if (index_type_size != 1) {
+      for (i = 0; i < primcount; i++) {
+	 if ((((uintptr_t)indices[i] - min_index_ptr) % index_type_size) != 0) {
+	    fallback = GL_TRUE;
+	    break;
+	 }
+      }
+   }
+
+   /* If the index buffer isn't in a VBO, then treating the application's
+    * subranges of the index buffer as one large index buffer may lead to
+    * us reading unmapped memory.
+    */
+   if (!_mesa_is_bufferobj(ctx->Array.ElementArrayBufferObj))
+      fallback = GL_TRUE;
+
+   if (!fallback) {
+      ib.count = (max_index_ptr - min_index_ptr) / index_type_size;
+      ib.type = type;
+      ib.obj = ctx->Array.ElementArrayBufferObj;
+      ib.ptr = (void *)min_index_ptr;
+
+      for (i = 0; i < primcount; i++) {
+	 prim[i].begin = (i == 0);
+	 prim[i].end = (i == primcount - 1);
+	 prim[i].weak = 0;
+	 prim[i].pad = 0;
+	 prim[i].mode = mode;
+	 prim[i].start = ((uintptr_t)indices[i] - min_index_ptr) / index_type_size;
+	 prim[i].count = count[i];
+	 prim[i].indexed = 1;
+      }
+
+      vbo->draw_prims(ctx, exec->array.inputs, prim, primcount, &ib,
+		      GL_FALSE, ~0, ~0);
+   } else {
+      for (i = 0; i < primcount; i++) {
+	 ib.count = count[i];
+	 ib.type = type;
+	 ib.obj = ctx->Array.ElementArrayBufferObj;
+	 ib.ptr = indices[i];
+
+
+	 prim[0].begin = 1;
+	 prim[0].end = 1;
+	 prim[0].weak = 0;
+	 prim[0].pad = 0;
+	 prim[0].mode = mode;
+	 prim[0].start = 0;
+	 prim[0].count = count[i];
+	 prim[0].indexed = 1;
+      }
+
+      vbo->draw_prims(ctx, exec->array.inputs, prim, 1, &ib,
+		      GL_FALSE, ~0, ~0);
+   }
+   _mesa_free(prim);
+}
+
+static void GLAPIENTRY
+vbo_exec_MultiDrawElements(GLenum mode,
+			   const GLsizei *count, GLenum type,
+			   const GLvoid **indices,
+			   GLsizei primcount)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   GLint i;
+
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
+
+   for (i = 0; i < primcount; i++) {
+      if (!_mesa_validate_DrawElements( ctx, mode, count[i], type, indices[i] ))
+	 return;
+   }
+
+   vbo_validated_multidrawelements(ctx, mode, count, type, indices, primcount);
+}
+
+
+
+/***********************************************************************
+ * Initialization
+ */
+
+void
+vbo_exec_array_init( struct vbo_exec_context *exec )
+{
+#if 1
+   exec->vtxfmt.DrawArrays = vbo_exec_DrawArrays;
+   exec->vtxfmt.DrawElements = vbo_exec_DrawElements;
+   exec->vtxfmt.DrawRangeElements = vbo_exec_DrawRangeElements;
+   exec->vtxfmt.MultiDrawElementsEXT = vbo_exec_MultiDrawElements;
+#else
+   exec->vtxfmt.DrawArrays = _mesa_noop_DrawArrays;
+   exec->vtxfmt.DrawElements = _mesa_noop_DrawElements;
+   exec->vtxfmt.DrawRangeElements = _mesa_noop_DrawRangeElements;
+   exec->vtxfmt.MultiDrawElementsEXT = _mesa_noop_MultiDrawElements;
+#endif
+}
+
+
+void
+vbo_exec_array_destroy( struct vbo_exec_context *exec )
+{
+   /* nothing to do */
+}
+
+
+/* This API entrypoint is not ordinarily used */
+void GLAPIENTRY
+_mesa_DrawArrays(GLenum mode, GLint first, GLsizei count)
+{
+   vbo_exec_DrawArrays(mode, first, count);
+}
+
+
+/* This API entrypoint is not ordinarily used */
+void GLAPIENTRY
+_mesa_DrawElements(GLenum mode, GLsizei count, GLenum type,
+                   const GLvoid *indices)
+{
+   vbo_exec_DrawElements(mode, count, type, indices);
+}
+
+
+/* This API entrypoint is not ordinarily used */
+void GLAPIENTRY
+_mesa_DrawRangeElements(GLenum mode, GLuint start, GLuint end, GLsizei count,
+                        GLenum type, const GLvoid *indices)
+{
+   vbo_exec_DrawRangeElements(mode, start, end, count, type, indices);
+}
+
+/* GL_EXT_multi_draw_arrays */
+void GLAPIENTRY
+_mesa_MultiDrawElementsEXT(GLenum mode, const GLsizei *count, GLenum type,
+			   const GLvoid **indices, GLsizei primcount)
+{
+   vbo_exec_MultiDrawElements(mode, count, type, indices, primcount);
+}