src/mesa/drivers/dri/i965/gen6_sol.c

   1 /*
   2  * Copyright © 2011 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 /** \file gen6_sol.c
  25  *
  26  * Code to initialize the binding table entries used by transform feedback.
  27  */
  28
  29 #include "main/macros.h"
  30 #include "brw_context.h"
  31 #include "intel_batchbuffer.h"
  32 #include "brw_defines.h"
  33
  34 static void
  35 gen6_update_sol_surfaces(struct brw_context *brw)
  36 {
  37    struct gl_context *ctx = &brw->intel.ctx;
  38    /* _NEW_TRANSFORM_FEEDBACK */
  39    struct gl_transform_feedback_object *xfb_obj =
  40       ctx->TransformFeedback.CurrentObject;
  41    /* BRW_NEW_VERTEX_PROGRAM */
  42    const struct gl_shader_program *shaderprog =
  43       ctx->Shader.CurrentVertexProgram;
  44    const struct gl_transform_feedback_info *linked_xfb_info =
  45       &shaderprog->LinkedTransformFeedback;
  46    int i;
  47
  48    for (i = 0; i < BRW_MAX_SOL_BINDINGS; ++i) {
  49       const int surf_index = SURF_INDEX_SOL_BINDING(i);
  50       if (xfb_obj->Active && i < linked_xfb_info->NumOutputs) {
  51          unsigned buffer = linked_xfb_info->Outputs[i].OutputBuffer;
  52          unsigned buffer_offset =
  53             xfb_obj->Offset[buffer] / 4 +
  54             linked_xfb_info->Outputs[i].DstOffset;
  55          brw_update_sol_surface(
  56             brw, xfb_obj->Buffers[buffer], &brw->bind.surf_offset[surf_index],
  57             linked_xfb_info->Outputs[i].NumComponents,
  58             linked_xfb_info->BufferStride[buffer], buffer_offset);
  59       } else {
  60          brw->bind.surf_offset[surf_index] = 0;
  61       }
  62    }
  63 }
  64
  65 const struct brw_tracked_state gen6_sol_surface = {
  66    .dirty = {
  67       .mesa = _NEW_TRANSFORM_FEEDBACK,
  68       .brw = (BRW_NEW_BATCH |
  69               BRW_NEW_VERTEX_PROGRAM),
  70       .cache = 0
  71    },
  72    .emit = gen6_update_sol_surfaces,
  73 };
  74
  75 void
  76 brw_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
  77                              struct gl_transform_feedback_object *obj)
  78 {
  79    struct intel_context *intel = intel_context(ctx);
  80    const struct gl_shader_program *vs_prog =
  81       ctx->Shader.CurrentVertexProgram;
  82    const struct gl_transform_feedback_info *linked_xfb_info =
  83       &vs_prog->LinkedTransformFeedback;
  84    struct gl_transform_feedback_object *xfb_obj =
  85       ctx->TransformFeedback.CurrentObject;
  86
  87    unsigned max_index = 0xffffffff;
  88
  89    /* Compute the maximum number of vertices that we can write without
  90     * overflowing any of the buffers currently being used for feedback.
  91     */
  92    for (int i = 0; i < BRW_MAX_SOL_BUFFERS; ++i) {
  93       unsigned stride = linked_xfb_info->BufferStride[i];
  94
  95       /* Skip any inactive buffers, which have a stride of 0. */
  96       if (stride == 0)
  97          continue;
  98
  99       unsigned max_for_this_buffer = xfb_obj->Size[i] / (4 * stride);
 100       max_index = MIN2(max_index, max_for_this_buffer);
 101    }
 102
 103    /* Initialize the SVBI 0 register to zero and set the maximum index. */
 104    BEGIN_BATCH(4);
 105    OUT_BATCH(_3DSTATE_GS_SVB_INDEX << 16 | (4 - 2));
 106    OUT_BATCH(0); /* SVBI 0 */
 107    OUT_BATCH(0);
 108    OUT_BATCH(max_index);
 109    ADVANCE_BATCH();
 110 }
 111
 112 void
 113 brw_end_transform_feedback(struct gl_context *ctx,
 114                            struct gl_transform_feedback_object *obj)
 115 {
 116    /* After EndTransformFeedback, it's likely that the client program will try
 117     * to draw using the contents of the transform feedback buffer as vertex
 118     * input.  In order for this to work, we need to flush the data through at
 119     * least the GS stage of the pipeline, and flush out the render cache.  For
 120     * simplicity, just do a full flush.
 121     */
 122    struct brw_context *brw = brw_context(ctx);
 123    struct intel_context *intel = &brw->intel;
 124    intel_batchbuffer_emit_mi_flush(intel);
 125 }