[Mesa-dev] [PATCH v2] i965: Implement CopyTexSubImage2D via BLORP (and use it by default).
Kenneth Graunke
kenneth at whitecape.org
Mon Jan 28 14:34:33 PST 2013
The BLT engine has many limitations. Currently, it can only blit
X-tiled buffers (since we don't have a kernel API to whack the BLT
tiling mode register), which means all depth/stencil operations get
punted to meta code, which can be very CPU-intensive.
Even if we used the BLT engine, it can't blit between buffers with
different tiling modes, such as an X-tiled non-MSAA ARGB8888 texture
and a Y-tiled CMS ARGB8888 renderbuffer. This is a fundamental
limitation, and the only way around that is to use BLORP.
Previously, BLORP only handled BlitFramebuffer. This patch adds an
additional frontend for doing CopyTexSubImage. It also makes it the
default. This is partly to increase testing and avoid hiding bugs,
and partly because the BLORP path can already handle more cases. With
trivial extensions, it should be able to handle everything the BLT can.
This helps PlaneShift massively, which tries to CopyTexSubImage2D
between depth buffers whenever a player casts a spell. Since these
are Y-tiled, we hit meta and software ReadPixels paths, eating 99% CPU
while delivering ~1 FPS. This is particularly bad in an MMO setting
because people cast spells all the time.
It also helps Xonotic in 4X MSAA mode. At default power management
settings, I measured a 6.35138% +/- 0.672548% performance boost (n=5).
(This data is from v1 of the patch.)
No Piglit regressions on Ivybridge. I have not tested Sandybridge.
v2: Create a fake intel_renderbuffer to wrap the destination texture
image and then reuse do_blorp_blit rather than reimplementing most
of it. Remove unnecessary clipping code and conditional rendering
check.
Cc: Paul Berry <stereotype441 at gmail.com>
Cc: Chad Versace <chad.versace at linux.intel.com>
---
src/mesa/drivers/dri/i965/brw_blorp_blit.cpp | 64 ++++++++++++++++++++++++++++
src/mesa/drivers/dri/i965/brw_context.h | 8 ++++
src/mesa/drivers/dri/intel/intel_fbo.c | 30 +++++++++++++
src/mesa/drivers/dri/intel/intel_fbo.h | 4 ++
src/mesa/drivers/dri/intel/intel_tex_copy.c | 32 ++++++++++----
5 files changed, 130 insertions(+), 8 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
index bc7916a..e5f12fe 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
@@ -295,6 +295,70 @@ try_blorp_blit(struct intel_context *intel,
return true;
}
+bool
+brw_blorp_copytexsubimage(struct intel_context *intel,
+ struct gl_renderbuffer *src_rb,
+ struct gl_texture_image *dst_image,
+ int srcX0, int srcY0,
+ int dstX0, int dstY0,
+ int width, int height)
+{
+ struct gl_context *ctx = &intel->ctx;
+
+ /* BLORP is not supported before Gen6. */
+ if (intel->gen < 6)
+ return false;
+
+ /* BLORP requires the formats to match. In the future, we should relax
+ * this for simple format mismatches like XRGB <-> ARGB.
+ */
+ if (_mesa_get_srgb_format_linear(src_rb->Format) !=
+ _mesa_get_srgb_format_linear(dst_image->TexFormat))
+ return false;
+
+ /* Sync up the state of window system buffers. We need to do this before
+ * we go looking for the buffers.
+ */
+ intel_prepare_render(intel);
+
+ int srcY1 = srcY0 + height;
+ int dstX1 = dstX0 + width;
+ int dstY1 = dstY0 + height;
+
+ /* Source clipping shouldn't be necessary, since copytexsubimage (in
+ * src/mesa/main/teximage.c) calls _mesa_clip_copytexsubimage() which
+ * takes care of it.
+ *
+ * Destination clipping shouldn't be necessary since the restrictions on
+ * glCopyTexSubImage prevent the user from specifying a destination rectangle
+ * that falls outside the bounds of the destination texture.
+ * See error_check_subtexture_dimensions().
+ */
+
+ /* Account for the fact that in the system framebuffer, the origin is at
+ * the lower left.
+ */
+ bool mirror_y = false;
+ if (_mesa_is_winsys_fbo(ctx->ReadBuffer)) {
+ GLint tmp = src_rb->Height - srcY0;
+ srcY0 = src_rb->Height - srcY1;
+ srcY1 = tmp;
+ mirror_y = true;
+ }
+
+ /* Create a fake/wrapper renderbuffer to allow us to use do_blorp_blit(). */
+ struct intel_renderbuffer *dst_irb =
+ intel_create_fake_renderbuffer_wrapper(intel, dst_image);
+ if (!dst_irb)
+ return false;
+
+ do_blorp_blit(intel, ~0, intel_renderbuffer(src_rb), dst_irb,
+ srcX0, srcY0, dstX0, dstY0, dstX1, dstY1, false, mirror_y);
+
+ return true;
+}
+
+
GLbitfield
brw_blorp_framebuffer(struct intel_context *intel,
GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index f3a3efe..3976ef8 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -1219,6 +1219,14 @@ brw_blorp_framebuffer(struct intel_context *intel,
GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
GLbitfield mask, GLenum filter);
+bool
+brw_blorp_copytexsubimage(struct intel_context *intel,
+ struct gl_renderbuffer *src_rb,
+ struct gl_texture_image *dst_image,
+ int srcX0, int srcY0,
+ int dstX0, int dstY0,
+ int width, int height);
+
/* gen6_multisample_state.c */
void
gen6_emit_3dstate_multisample(struct brw_context *brw,
diff --git a/src/mesa/drivers/dri/intel/intel_fbo.c b/src/mesa/drivers/dri/intel/intel_fbo.c
index 4810809..37ecbd1 100644
--- a/src/mesa/drivers/dri/intel/intel_fbo.c
+++ b/src/mesa/drivers/dri/intel/intel_fbo.c
@@ -531,6 +531,36 @@ intel_renderbuffer_update_wrapper(struct intel_context *intel,
return true;
}
+/**
+ * Create a fake intel_renderbuffer that wraps a gl_texture_image.
+ */
+struct intel_renderbuffer *
+intel_create_fake_renderbuffer_wrapper(struct intel_context *intel,
+ struct gl_texture_image *image)
+{
+ struct gl_context *ctx = &intel->ctx;
+ struct intel_renderbuffer *irb;
+ struct gl_renderbuffer *rb;
+
+ irb = CALLOC_STRUCT(intel_renderbuffer);
+ if (!irb) {
+ _mesa_error(ctx, GL_OUT_OF_MEMORY, "creating renderbuffer");
+ return NULL;
+ }
+
+ rb = &irb->Base.Base;
+
+ _mesa_init_renderbuffer(rb, 0);
+ rb->ClassID = INTEL_RB_CLASS;
+
+ if (!intel_renderbuffer_update_wrapper(intel, irb, image, image->Face)) {
+ intel_delete_renderbuffer(ctx, rb);
+ return NULL;
+ }
+
+ return irb;
+}
+
void
intel_renderbuffer_set_draw_offset(struct intel_renderbuffer *irb)
{
diff --git a/src/mesa/drivers/dri/intel/intel_fbo.h b/src/mesa/drivers/dri/intel/intel_fbo.h
index 9c48e9c..f135dea 100644
--- a/src/mesa/drivers/dri/intel/intel_fbo.h
+++ b/src/mesa/drivers/dri/intel/intel_fbo.h
@@ -140,6 +140,10 @@ intel_create_wrapped_renderbuffer(struct gl_context * ctx,
int width, int height,
gl_format format);
+struct intel_renderbuffer *
+intel_create_fake_renderbuffer_wrapper(struct intel_context *intel,
+ struct gl_texture_image *image);
+
extern void
intel_fbo_init(struct intel_context *intel);
diff --git a/src/mesa/drivers/dri/intel/intel_tex_copy.c b/src/mesa/drivers/dri/intel/intel_tex_copy.c
index 1af7b1c..0a3dfef 100644
--- a/src/mesa/drivers/dri/intel/intel_tex_copy.c
+++ b/src/mesa/drivers/dri/intel/intel_tex_copy.c
@@ -41,6 +41,9 @@
#include "intel_fbo.h"
#include "intel_tex.h"
#include "intel_blit.h"
+#ifndef I915
+#include "brw_context.h"
+#endif
#define FILE_DEBUG_FLAG DEBUG_TEXTURE
@@ -156,15 +159,28 @@ intelCopyTexSubImage(struct gl_context *ctx, GLuint dims,
GLint x, GLint y,
GLsizei width, GLsizei height)
{
- if (dims == 3 || !intel_copy_texsubimage(intel_context(ctx),
- intel_texture_image(texImage),
- xoffset, yoffset,
- intel_renderbuffer(rb), x, y, width, height)) {
- fallback_debug("%s - fallback to swrast\n", __FUNCTION__);
- _mesa_meta_CopyTexSubImage(ctx, dims, texImage,
- xoffset, yoffset, zoffset,
- rb, x, y, width, height);
+ struct intel_context *intel = intel_context(ctx);
+ if (dims != 3) {
+#ifndef I915
+ /* Try BLORP first. It can handle almost everything. */
+ if (brw_blorp_copytexsubimage(intel, rb, texImage, x, y,
+ xoffset, yoffset, width, height))
+ return;
+#endif
+
+ /* Next, try the BLT engine. */
+ if (intel_copy_texsubimage(intel_context(ctx),
+ intel_texture_image(texImage),
+ xoffset, yoffset,
+ intel_renderbuffer(rb), x, y, width, height))
+ return;
}
+
+ /* Finally, fall back to meta. This will likely be slow. */
+ fallback_debug("%s - fallback to swrast\n", __FUNCTION__);
+ _mesa_meta_CopyTexSubImage(ctx, dims, texImage,
+ xoffset, yoffset, zoffset,
+ rb, x, y, width, height);
}
--
1.8.1.1
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