mesa: initial check-in of transform feedback functions

1 files changed, 427 insertions, 0 deletions

diff --git a/src/mesa/main/transformfeedback.c b/src/mesa/main/transformfeedback.c
new file mode 100644
index 00000000000..3490110baef
--- /dev/null
+++ b/src/mesa/main/transformfeedback.c
@@ -0,0 +1,427 @@
+/*
+ * 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 "enums.h"
+#include "transformfeedback.h"
+
+#include "shader/prog_parameter.h"
+#include "shader/shader_api.h"
+
+
+/**
+ * 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.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)
+{
+
+   return GL_TRUE;
+}
+
+
+
+/**
+ * Per-context init for transform feedback.
+ */
+void
+_mesa_init_transform_feedback(GLcontext *ctx)
+{
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.CurrentBuffer,
+                                 ctx->Shared->NullBufferObj);
+}
+
+
+/**
+ * Per-context free/clean-up for transform feedback.
+ */
+void
+_mesa_free_transform_feedback(GLcontext *ctx)
+{
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.CurrentBuffer,
+                                 NULL);
+}
+
+
+void GLAPIENTRY
+_mesa_BeginTransformFeedback(GLenum mode)
+{
+   GET_CURRENT_CONTEXT(ctx);
+
+   switch (mode) {
+   case GL_POINTS:
+   case GL_LINES:
+   case GL_TRIANGLES:
+      /* legal */
+      break;
+   default:
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBeginTransformFeedback(mode)");
+      return;
+   }
+
+   if (ctx->TransformFeedback.Active) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBeginTransformFeedback(already active)");
+      return;
+   }
+
+   ctx->TransformFeedback.Active = GL_TRUE;
+   ctx->TransformFeedback.Mode = mode;
+}
+
+
+void GLAPIENTRY
+_mesa_EndTransformFeedback(void)
+{
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (!ctx->TransformFeedback.Active) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glEndTransformFeedback(not active)");
+      return;
+   }
+
+   ctx->TransformFeedback.Active = GL_FALSE;
+}
+
+
+/**
+ * Helper used by BindBufferRange() and BindBufferBase().
+ */
+static void
+bind_buffer_range(GLcontext *ctx, GLuint index,
+                  struct gl_buffer_object *bufObj,
+                  GLintptr offset, GLsizeiptr size)
+{
+   /* The general binding point */
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.CurrentBuffer,
+                                 bufObj);
+
+   /* The per-attribute binding point */
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->TransformFeedback.Buffers[index],
+                                 bufObj);
+
+   ctx->TransformFeedback.BufferNames[index] = bufObj->Name;
+
+   ctx->TransformFeedback.Offset[index] = offset;
+   ctx->TransformFeedback.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_buffer_object *bufObj;
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (target != GL_TRANSFORM_FEEDBACK_BUFFER) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferRange(target)");
+      return;
+   }
+
+   if (ctx->TransformFeedback.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)", size);
+      return;
+   }  
+
+   if (offset & 0x3) {
+      /* must be multiple of four */
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glBindBufferRange(offset=%d)", 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 > buffer size)", 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_buffer_object *bufObj;
+   GET_CURRENT_CONTEXT(ctx);
+   GLsizeiptr size;
+
+   if (target != GL_TRANSFORM_FEEDBACK_BUFFER) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferBase(target)");
+      return;
+   }
+
+   if (ctx->TransformFeedback.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_buffer_object *bufObj;
+   GET_CURRENT_CONTEXT(ctx);
+   GLsizeiptr size;
+
+   if (target != GL_TRANSFORM_FEEDBACK_BUFFER) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferOffsetEXT(target)");
+      return;
+   }
+
+   if (ctx->TransformFeedback.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->Type;
+      if (size)
+         *size = param->Size;
+   }
+}
+