Mesa (master): i965: implement blit path for PBO glDrawPixels

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: 279e8d264109303f0e8248ab4c3703c71f65983f
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=279e8d264109303f0e8248ab4c3703c71f65983f

Author: Alexander Monakov <amonakov at gmail.com>
Date:   Mon Nov  4 01:34:32 2013 +0400

i965: implement blit path for PBO glDrawPixels

This patch implements accelerated path for glDrawPixels from a PBO in
i965. The code follows what intel_pixel_read, intel_pixel_copy,
intel_pixel_bitmap and intel_tex_image are doing. Piglit quick.tests
show no regressions. In my testing on IVB, performance improvement is
huge (about 30x, didn't measure exactly) since generic path goes via
_mesa_unpack_color_span_float, memcpy, extract_float_rgba.

Signed-off-by: Alexander Monakov <amonakov at ispras.ru>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/mesa/drivers/dri/i965/intel_pixel.c      |    5 +
 src/mesa/drivers/dri/i965/intel_pixel_draw.c |  115 ++++++++++++++++++++++++++
 2 files changed, 120 insertions(+), 0 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_pixel.c b/src/mesa/drivers/dri/i965/intel_pixel.c
index 623f4f4..fc70381 100644
--- a/src/mesa/drivers/dri/i965/intel_pixel.c
+++ b/src/mesa/drivers/dri/i965/intel_pixel.c
@@ -115,6 +115,11 @@ intel_check_blit_fragment_ops(struct gl_context * ctx, bool src_alpha_is_one)
       return false;
    }
 
+   if (ctx->Pixel.ZoomX != 1.0F || ctx->Pixel.ZoomY != 1.0F) {
+      DBG("fallback due to pixel zoom\n");
+      return false;
+   }
+
    if (ctx->RenderMode != GL_RENDER) {
       DBG("fallback due to render mode\n");
       return false;
diff --git a/src/mesa/drivers/dri/i965/intel_pixel_draw.c b/src/mesa/drivers/dri/i965/intel_pixel_draw.c
index af618a2..477586e 100644
--- a/src/mesa/drivers/dri/i965/intel_pixel_draw.c
+++ b/src/mesa/drivers/dri/i965/intel_pixel_draw.c
@@ -29,14 +29,115 @@
 #include "main/enums.h"
 #include "main/image.h"
 #include "main/mtypes.h"
+#include "main/condrender.h"
+#include "main/fbobject.h"
 #include "main/teximage.h"
 #include "main/texobj.h"
 #include "main/texstate.h"
+#include "main/bufferobj.h"
 #include "swrast/swrast.h"
 #include "drivers/common/meta.h"
 
 #include "brw_context.h"
+#include "intel_screen.h"
+#include "intel_blit.h"
+#include "intel_buffers.h"
+#include "intel_fbo.h"
+#include "intel_mipmap_tree.h"
+#include "intel_regions.h"
 #include "intel_pixel.h"
+#include "intel_buffer_objects.h"
+
+#define FILE_DEBUG_FLAG DEBUG_PIXEL
+
+static bool
+do_blit_drawpixels(struct gl_context * ctx,
+		   GLint x, GLint y, GLsizei width, GLsizei height,
+		   GLenum format, GLenum type,
+		   const struct gl_pixelstore_attrib *unpack,
+		   const GLvoid * pixels)
+{
+   struct brw_context *brw = brw_context(ctx);
+   struct intel_buffer_object *src = intel_buffer_object(unpack->BufferObj);
+   GLuint src_offset;
+   drm_intel_bo *src_buffer;
+
+   DBG("%s\n", __FUNCTION__);
+
+   if (!intel_check_blit_fragment_ops(ctx, false))
+      return false;
+
+   if (ctx->DrawBuffer->_NumColorDrawBuffers != 1) {
+      DBG("%s: fallback due to MRT\n", __FUNCTION__);
+      return false;
+   }
+
+   struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
+   struct intel_renderbuffer *irb = intel_renderbuffer(rb);
+
+   if (!_mesa_format_matches_format_and_type(irb->mt->format, format, type,
+                                             false)) {
+      DBG("%s: bad format for blit\n", __FUNCTION__);
+      return false;
+   }
+
+   if (unpack->SwapBytes || unpack->LsbFirst ||
+       unpack->SkipPixels || unpack->SkipRows) {
+      DBG("%s: bad packing params\n", __FUNCTION__);
+      return false;
+   }
+
+   int src_stride = _mesa_image_row_stride(unpack, width, format, type);
+   bool src_flip = false;
+   /* Mesa flips the src_stride for unpack->Invert, but we want our mt to have
+    * a normal src_stride.
+    */
+   if (unpack->Invert) {
+      src_stride = -src_stride;
+      src_flip = true;
+   }
+
+   src_offset = (GLintptr)pixels;
+   src_offset += _mesa_image_offset(2, unpack, width, height,
+				    format, type, 0, 0, 0);
+
+   intel_prepare_render(brw);
+
+   src_buffer = intel_bufferobj_buffer(brw, src,
+				       src_offset, width * height *
+                                       irb->mt->cpp);
+
+   struct intel_mipmap_tree *pbo_mt =
+      intel_miptree_create_for_bo(brw,
+                                  src_buffer,
+                                  irb->mt->format,
+                                  src_offset,
+                                  width, height,
+                                  src_stride, I915_TILING_NONE);
+   if (!pbo_mt)
+      return false;
+
+   if (!intel_miptree_blit(brw,
+                           pbo_mt, 0, 0,
+                           0, 0, src_flip,
+                           irb->mt, irb->mt_level, irb->mt_layer,
+                           x, y, _mesa_is_winsys_fbo(ctx->DrawBuffer),
+                           width, height, GL_COPY)) {
+      DBG("%s: blit failed\n", __FUNCTION__);
+      intel_miptree_release(&pbo_mt);
+      return false;
+   }
+
+   intel_miptree_release(&pbo_mt);
+
+   if (ctx->Query.CurrentOcclusionObject)
+      ctx->Query.CurrentOcclusionObject->Result += width * height;
+
+   intel_check_front_buffer_rendering(brw);
+
+   DBG("%s: success\n", __FUNCTION__);
+   return true;
+}
 
 void
 intelDrawPixels(struct gl_context * ctx,
@@ -47,12 +148,26 @@ intelDrawPixels(struct gl_context * ctx,
                 const struct gl_pixelstore_attrib *unpack,
                 const GLvoid * pixels)
 {
+   struct brw_context *brw = brw_context(ctx);
+
+   if (!_mesa_check_conditional_render(ctx))
+      return;
+
    if (format == GL_STENCIL_INDEX) {
       _swrast_DrawPixels(ctx, x, y, width, height, format, type,
                          unpack, pixels);
       return;
    }
 
+   if (_mesa_is_bufferobj(unpack->BufferObj)) {
+      if (do_blit_drawpixels(ctx, x, y, width, height, format, type, unpack,
+			     pixels)) {
+	 return;
+      }
+
+      perf_debug("%s: fallback to generic code in PBO case\n", __FUNCTION__);
+   }
+
    _mesa_meta_DrawPixels(ctx, x, y, width, height, format, type,
                          unpack, pixels);
 }