On 2016-05-27 11:05, Tan Hu wrote:
Subpixel text rendering is typically done with a solid src and
a pixmap mask. Traditionally, this cannot be accelerated in a single
pass and requires two passes [1]. However, we can cheat a little
with a constant blend color.
We can use:
const.A = src.A / src.A
const.R = src.R / src.A
const.G = src.G / src.A
const.B = src.B / src.A
dst.A = const.A * (src.A * mask.A) + (1 - (src.A * mask.A)) * dst.A
dst.R = const.R * (src.A * mask.R) + (1 - (src.A * mask.R)) * dst.R
dst.G = const.G * (src.A * mask.G) + (1 - (src.A * mask.G)) * dst.G
dst.B = const.B * (src.A * mask.B) + (1 - (src.A * mask.B)) * dst.B
This only needs a single source value. src.A is cancelled down in
the right places.
With Michel's comments addressed,
Reviewed-by: Grigori Goronzy <[email protected]>
[1] http://anholt.livejournal.com/32058.html
r6xx still be used on some machine,
Ported from commit 4375a6e75e5d41139be7031a0dee58c057ecbd07.
Signed-off-by: Tan Hu <[email protected]>
---
src/r600_exa.c | 22 ++++++++++++++++++++--
src/r600_state.h | 2 ++
src/r6xx_accel.c | 14 ++++++++++++++
3 files changed, 36 insertions(+), 2 deletions(-)
diff --git a/src/r600_exa.c b/src/r600_exa.c
index a95f320..849b21a 100644
--- a/src/r600_exa.c
+++ b/src/r600_exa.c
@@ -766,6 +766,14 @@ static uint32_t R600GetBlendCntl(int op,
PicturePtr pMask, uint32_t dst_format)
} else if (dblend == (BLEND_ONE_MINUS_SRC_ALPHA <<
COLOR_DESTBLEND_shift)) {
dblend = (BLEND_ONE_MINUS_SRC_COLOR << COLOR_DESTBLEND_shift);
}
+
+ /* With some tricks, we can still accelerate PictOpOver with solid
src.
+ * This is commonly used for text rendering, so it's worth the extra
+ * effort.
+ */
+ if (sblend == (BLEND_ONE << COLOR_SRCBLEND_shift)) {
+ sblend = (BLEND_CONSTANT_COLOR << COLOR_SRCBLEND_shift);
+ }
}
return sblend | dblend;
@@ -1143,12 +1151,17 @@ static Bool R600CheckComposite(int op,
PicturePtr pSrcPicture, PicturePtr pMaskP
/* Check if it's component alpha that relies on a source alpha
and
* on the source value. We can only get one of those into the
* single source value that we get to blend with.
+ *
+ * We can cheat a bit if the src is solid, though. PictOpOver
+ * can use the constant blend color to sneak a second blend
+ * source in.
*/
if (R600BlendOp[op].src_alpha &&
(R600BlendOp[op].blend_cntl & COLOR_SRCBLEND_mask) !=
(BLEND_ZERO << COLOR_SRCBLEND_shift)) {
- RADEON_FALLBACK(("Component alpha not supported with source
"
- "alpha and source value blending.\n"));
+ if (pSrcPicture->pDrawable || op != PictOpOver)
+ RADEON_FALLBACK(("Component alpha not supported with
source "
+ "alpha and source value blending.\n"));
}
}
@@ -1244,6 +1257,11 @@ static void R600SetSolidConsts(ScrnInfoPtr
pScrn, float *buf, int format, uint32
} else {
if (accel_state->component_alpha) {
if (accel_state->src_alpha) {
+ /* required for PictOpOver */
+ float cblend[4] = { pix_r / pix_a, pix_g / pix_a,
+ pix_b / pix_a, pix_a / pix_a };
+ r600_set_blend_color(pScrn, cblend);
+
if (PICT_FORMAT_A(format) == 0) {
pix_r = 1.0;
pix_g = 1.0;
diff --git a/src/r600_state.h b/src/r600_state.h
index fa777e8..fda297d 100644
--- a/src/r600_state.h
+++ b/src/r600_state.h
@@ -266,6 +266,8 @@ r600_wait_3d_idle(ScrnInfoPtr pScrn);
void
r600_start_3d(ScrnInfoPtr pScrn);
void
+r600_set_blend_color(ScrnInfoPtr pScrn, float *color);
+void
r600_set_render_target(ScrnInfoPtr pScrn, cb_config_t *cb_conf,
uint32_t domain);
void
r600_cp_wait_vline_sync(ScrnInfoPtr pScrn, PixmapPtr pPix,
xf86CrtcPtr crtc, int start, int stop);
diff --git a/src/r6xx_accel.c b/src/r6xx_accel.c
index a97c84b..1f5c052 100644
--- a/src/r6xx_accel.c
+++ b/src/r6xx_accel.c
@@ -174,6 +174,20 @@ r600_sq_setup(ScrnInfoPtr pScrn, sq_config_t
*sq_conf)
END_BATCH();
}
+void r600_set_blend_color(ScrnInfoPtr pScrn, float *color)
+{
+ RADEONInfoPtr info = RADEONPTR(pScrn);
+
+ BEGIN_BATCH(2 + 4);
+ PACK0(CB_BLEND_RED, 4);
+ EFLOAT(color[0]); /* R */
+ EFLOAT(color[1]); /* G */
+ EFLOAT(color[2]); /* B */
+ EFLOAT(color[3]); /* A */
+ END_BATCH();
+}
+
+
void
r600_set_render_target(ScrnInfoPtr pScrn, cb_config_t *cb_conf,
uint32_t domain)
{
_______________________________________________
xorg-driver-ati mailing list
[email protected]
https://lists.x.org/mailman/listinfo/xorg-driver-ati
