[Mesa-dev] [PATCH] softpipe: implement blend color clamping
Brian Paul
brian.e.paul at gmail.com
Mon Sep 12 16:36:31 PDT 2011
From: Brian Paul <brianp at vmware.com>
Per the GL spec, clamp incoming colors prior to blending depending on
whether the destination buffer stores normalized (non-float) values.
Note that the constant blend color needs to be clamped too (we always
get the unclamped color from Mesa).
Fixes https://bugs.freedesktop.org/show_bug.cgi?id=40412
---
src/gallium/drivers/softpipe/sp_context.h | 1 +
src/gallium/drivers/softpipe/sp_quad_blend.c | 138 +++++++++++++++++++-----
src/gallium/drivers/softpipe/sp_state_blend.c | 7 ++
3 files changed, 117 insertions(+), 29 deletions(-)
diff --git a/src/gallium/drivers/softpipe/sp_context.h b/src/gallium/drivers/softpipe/sp_context.h
index 410b0a6..d51ce9f 100644
--- a/src/gallium/drivers/softpipe/sp_context.h
+++ b/src/gallium/drivers/softpipe/sp_context.h
@@ -75,6 +75,7 @@ struct softpipe_context {
/** Other rendering state */
struct pipe_blend_color blend_color;
+ struct pipe_blend_color blend_color_clamped;
struct pipe_stencil_ref stencil_ref;
struct pipe_clip_state clip;
struct pipe_resource *constants[PIPE_SHADER_TYPES][PIPE_MAX_CONSTANT_BUFFERS];
diff --git a/src/gallium/drivers/softpipe/sp_quad_blend.c b/src/gallium/drivers/softpipe/sp_quad_blend.c
index c881194..8fa75b3 100644
--- a/src/gallium/drivers/softpipe/sp_quad_blend.c
+++ b/src/gallium/drivers/softpipe/sp_quad_blend.c
@@ -41,6 +41,23 @@
#include "sp_quad_pipe.h"
+/** Subclass of quad_stage */
+struct blend_quad_stage
+{
+ struct quad_stage base;
+ boolean has_dst_alpha[PIPE_MAX_COLOR_BUFS];
+ boolean clamp[PIPE_MAX_COLOR_BUFS]; /*<< clamp colors to [0,1]? */
+};
+
+
+/** cast wrapper */
+static INLINE struct blend_quad_stage *
+blend_quad_stage(struct quad_stage *stage)
+{
+ return (struct blend_quad_stage *) stage;
+}
+
+
#define VEC4_COPY(DST, SRC) \
do { \
DST[0] = SRC[0]; \
@@ -226,6 +243,7 @@ logicop_quad(struct quad_stage *qs,
* Do blending for a 2x2 quad for one color buffer.
* \param quadColor the incoming quad colors
* \param dest the destination/framebuffer quad colors
+ * \param const_blend_color the constant blend color
* \param blend_index which set of blending terms to use
* \param has_dst_alpha does the dest color buffer have an alpha channel?
*/
@@ -233,6 +251,7 @@ static void
blend_quad(struct quad_stage *qs,
float (*quadColor)[4],
float (*dest)[4],
+ const float const_blend_color[4],
unsigned blend_index,
boolean has_dst_alpha)
{
@@ -301,18 +320,18 @@ blend_quad(struct quad_stage *qs,
case PIPE_BLENDFACTOR_CONST_COLOR:
{
float comp[4];
- VEC4_SCALAR(comp, softpipe->blend_color.color[0]); /* R */
+ VEC4_SCALAR(comp, const_blend_color[0]); /* R */
VEC4_MUL(source[0], quadColor[0], comp); /* R */
- VEC4_SCALAR(comp, softpipe->blend_color.color[1]); /* G */
+ VEC4_SCALAR(comp, const_blend_color[1]); /* G */
VEC4_MUL(source[1], quadColor[1], comp); /* G */
- VEC4_SCALAR(comp, softpipe->blend_color.color[2]); /* B */
+ VEC4_SCALAR(comp, const_blend_color[2]); /* B */
VEC4_MUL(source[2], quadColor[2], comp); /* B */
}
break;
case PIPE_BLENDFACTOR_CONST_ALPHA:
{
float alpha[4];
- VEC4_SCALAR(alpha, softpipe->blend_color.color[3]);
+ VEC4_SCALAR(alpha, const_blend_color[3]);
VEC4_MUL(source[0], quadColor[0], alpha); /* R */
VEC4_MUL(source[1], quadColor[1], alpha); /* G */
VEC4_MUL(source[2], quadColor[2], alpha); /* B */
@@ -378,20 +397,20 @@ blend_quad(struct quad_stage *qs,
{
float inv_comp[4];
/* R */
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[0]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[0]);
VEC4_MUL(source[0], quadColor[0], inv_comp);
/* G */
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[1]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[1]);
VEC4_MUL(source[1], quadColor[1], inv_comp);
/* B */
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[2]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[2]);
VEC4_MUL(source[2], quadColor[2], inv_comp);
}
break;
case PIPE_BLENDFACTOR_INV_CONST_ALPHA:
{
float inv_alpha[4];
- VEC4_SCALAR(inv_alpha, 1.0f - softpipe->blend_color.color[3]);
+ VEC4_SCALAR(inv_alpha, 1.0f - const_blend_color[3]);
VEC4_MUL(source[0], quadColor[0], inv_alpha); /* R */
VEC4_MUL(source[1], quadColor[1], inv_alpha); /* G */
VEC4_MUL(source[2], quadColor[2], inv_alpha); /* B */
@@ -439,7 +458,7 @@ blend_quad(struct quad_stage *qs,
case PIPE_BLENDFACTOR_CONST_ALPHA:
{
float comp[4];
- VEC4_SCALAR(comp, softpipe->blend_color.color[3]); /* A */
+ VEC4_SCALAR(comp, const_blend_color[3]); /* A */
VEC4_MUL(source[3], quadColor[3], comp); /* A */
}
break;
@@ -473,7 +492,7 @@ blend_quad(struct quad_stage *qs,
{
float inv_comp[4];
/* A */
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[3]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[3]);
VEC4_MUL(source[3], quadColor[3], inv_comp);
}
break;
@@ -539,18 +558,18 @@ blend_quad(struct quad_stage *qs,
case PIPE_BLENDFACTOR_CONST_COLOR:
{
float comp[4];
- VEC4_SCALAR(comp, softpipe->blend_color.color[0]); /* R */
+ VEC4_SCALAR(comp, const_blend_color[0]); /* R */
VEC4_MUL(blend_dest[0], blend_dest[0], comp); /* R */
- VEC4_SCALAR(comp, softpipe->blend_color.color[1]); /* G */
+ VEC4_SCALAR(comp, const_blend_color[1]); /* G */
VEC4_MUL(blend_dest[1], blend_dest[1], comp); /* G */
- VEC4_SCALAR(comp, softpipe->blend_color.color[2]); /* B */
+ VEC4_SCALAR(comp, const_blend_color[2]); /* B */
VEC4_MUL(blend_dest[2], blend_dest[2], comp); /* B */
}
break;
case PIPE_BLENDFACTOR_CONST_ALPHA:
{
float comp[4];
- VEC4_SCALAR(comp, softpipe->blend_color.color[3]); /* A */
+ VEC4_SCALAR(comp, const_blend_color[3]); /* A */
VEC4_MUL(blend_dest[0], blend_dest[0], comp); /* R */
VEC4_MUL(blend_dest[1], blend_dest[1], comp); /* G */
VEC4_MUL(blend_dest[2], blend_dest[2], comp); /* B */
@@ -615,20 +634,20 @@ blend_quad(struct quad_stage *qs,
{
float inv_comp[4];
/* R */
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[0]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[0]);
VEC4_MUL(blend_dest[0], blend_dest[0], inv_comp);
/* G */
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[1]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[1]);
VEC4_MUL(blend_dest[1], blend_dest[1], inv_comp);
/* B */
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[2]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[2]);
VEC4_MUL(blend_dest[2], blend_dest[2], inv_comp);
}
break;
case PIPE_BLENDFACTOR_INV_CONST_ALPHA:
{
float inv_comp[4];
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[3]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[3]);
VEC4_MUL(blend_dest[0], blend_dest[0], inv_comp);
VEC4_MUL(blend_dest[1], blend_dest[1], inv_comp);
VEC4_MUL(blend_dest[2], blend_dest[2], inv_comp);
@@ -673,7 +692,7 @@ blend_quad(struct quad_stage *qs,
case PIPE_BLENDFACTOR_CONST_ALPHA:
{
float comp[4];
- VEC4_SCALAR(comp, softpipe->blend_color.color[3]); /* A */
+ VEC4_SCALAR(comp, const_blend_color[3]); /* A */
VEC4_MUL(blend_dest[3], blend_dest[3], comp); /* A */
}
break;
@@ -706,7 +725,7 @@ blend_quad(struct quad_stage *qs,
case PIPE_BLENDFACTOR_INV_CONST_ALPHA:
{
float inv_comp[4];
- VEC4_SCALAR(inv_comp, 1.0f - softpipe->blend_color.color[3]);
+ VEC4_SCALAR(inv_comp, 1.0f - const_blend_color[3]);
VEC4_MUL(blend_dest[3], blend_dest[3], inv_comp);
}
break;
@@ -794,11 +813,28 @@ colormask_quad(unsigned colormask,
}
+/**
+ * Clamp all colors in a quad to [0, 1]
+ */
+static void
+clamp_colors(float (*quadColor)[4])
+{
+ unsigned i, j;
+
+ for (j = 0; j < QUAD_SIZE; j++) {
+ for (i = 0; i < 4; i++) {
+ quadColor[i][j] = CLAMP(quadColor[i][j], 0.0F, 1.0F);
+ }
+ }
+}
+
+
static void
blend_fallback(struct quad_stage *qs,
struct quad_header *quads[],
unsigned nr)
{
+ const struct blend_quad_stage *bqs = blend_quad_stage(qs);
struct softpipe_context *softpipe = qs->softpipe;
const struct pipe_blend_state *blend = softpipe->blend;
unsigned cbuf;
@@ -815,10 +851,15 @@ blend_fallback(struct quad_stage *qs,
= sp_get_cached_tile(softpipe->cbuf_cache[cbuf],
quads[0]->input.x0,
quads[0]->input.y0);
- boolean has_dst_alpha
- = util_format_has_alpha(softpipe->framebuffer.cbufs[cbuf]->format);
+ const boolean clamp = bqs->clamp[cbuf];
+ const float *blend_color;
uint q, i, j;
+ if (clamp)
+ blend_color = softpipe->blend_color_clamped.color;
+ else
+ blend_color = softpipe->blend_color.color;
+
for (q = 0; q < nr; q++) {
struct quad_header *quad = quads[q];
float (*quadColor)[4];
@@ -837,6 +878,13 @@ blend_fallback(struct quad_stage *qs,
quadColor = quad->output.color[cbuf];
}
+ /* If fixed-point dest color buffer, need to clamp the incoming
+ * fragment colors now.
+ */
+ if (clamp) {
+ clamp_colors(quadColor);
+ }
+
/* get/swizzle dest colors
*/
for (j = 0; j < QUAD_SIZE; j++) {
@@ -852,7 +900,8 @@ blend_fallback(struct quad_stage *qs,
logicop_quad( qs, quadColor, dest );
}
else if (blend->rt[blend_buf].blend_enable) {
- blend_quad( qs, quadColor, dest, blend_buf, has_dst_alpha );
+ blend_quad( qs, quadColor, dest, blend_color,
+ blend_buf, bqs->has_dst_alpha[cbuf] );
}
if (blend->rt[blend_buf].colormask != 0xf)
@@ -939,6 +988,7 @@ blend_single_add_one_one(struct quad_stage *qs,
struct quad_header *quads[],
unsigned nr)
{
+ const struct blend_quad_stage *bqs = blend_quad_stage(qs);
float dest[4][QUAD_SIZE];
uint i, j, q;
@@ -962,6 +1012,13 @@ blend_single_add_one_one(struct quad_stage *qs,
}
}
+ /* If fixed-point dest color buffer, need to clamp the incoming
+ * fragment colors now.
+ */
+ if (bqs->clamp[0]) {
+ clamp_colors(quadColor);
+ }
+
VEC4_ADD_SAT(quadColor[0], quadColor[0], dest[0]); /* R */
VEC4_ADD_SAT(quadColor[1], quadColor[1], dest[1]); /* G */
VEC4_ADD_SAT(quadColor[2], quadColor[2], dest[2]); /* B */
@@ -980,6 +1037,12 @@ blend_single_add_one_one(struct quad_stage *qs,
}
+/**
+ * Just copy the quad color to the framebuffer tile (respecting the writemask),
+ * for one color buffer.
+ * Clamping will be done, if needed (depending on the color buffer's
+ * datatype) when we write/pack the colors later.
+ */
static void
single_output_color(struct quad_stage *qs,
struct quad_header *quads[],
@@ -1023,8 +1086,10 @@ choose_blend_quad(struct quad_stage *qs,
struct quad_header *quads[],
unsigned nr)
{
+ struct blend_quad_stage *bqs = blend_quad_stage(qs);
struct softpipe_context *softpipe = qs->softpipe;
const struct pipe_blend_state *blend = softpipe->blend;
+ unsigned i;
qs->run = blend_fallback;
@@ -1055,6 +1120,18 @@ choose_blend_quad(struct quad_stage *qs,
}
}
+ /* For each color buffer, determine if the buffer has destination alpha and
+ * whether color clamping is needed.
+ */
+ for (i = 0; i < softpipe->framebuffer.nr_cbufs; i++) {
+ const enum pipe_format format = softpipe->framebuffer.cbufs[i]->format;
+ const struct util_format_description *desc =
+ util_format_description(format);
+ bqs->has_dst_alpha[i] = util_format_has_alpha(format);
+ /* assuming all or no color channels are normalized: */
+ bqs->clamp[i] = desc->channel[0].normalized;
+ }
+
qs->run(qs, quads, nr);
}
@@ -1073,12 +1150,15 @@ static void blend_destroy(struct quad_stage *qs)
struct quad_stage *sp_quad_blend_stage( struct softpipe_context *softpipe )
{
- struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
+ struct blend_quad_stage *stage = CALLOC_STRUCT(blend_quad_stage);
+
+ if (!stage)
+ return NULL;
- stage->softpipe = softpipe;
- stage->begin = blend_begin;
- stage->run = choose_blend_quad;
- stage->destroy = blend_destroy;
+ stage->base.softpipe = softpipe;
+ stage->base.begin = blend_begin;
+ stage->base.run = choose_blend_quad;
+ stage->base.destroy = blend_destroy;
- return stage;
+ return &stage->base;
}
diff --git a/src/gallium/drivers/softpipe/sp_state_blend.c b/src/gallium/drivers/softpipe/sp_state_blend.c
index 1286382..1fbc5f3 100644
--- a/src/gallium/drivers/softpipe/sp_state_blend.c
+++ b/src/gallium/drivers/softpipe/sp_state_blend.c
@@ -28,6 +28,7 @@
/* Authors: Keith Whitwell <keith at tungstengraphics.com>
*/
+#include "util/u_math.h"
#include "util/u_memory.h"
#include "draw/draw_context.h"
#include "sp_context.h"
@@ -69,11 +70,17 @@ softpipe_set_blend_color(struct pipe_context *pipe,
const struct pipe_blend_color *blend_color)
{
struct softpipe_context *softpipe = softpipe_context(pipe);
+ unsigned i;
draw_flush(softpipe->draw);
softpipe->blend_color = *blend_color;
+ /* save clamped color too */
+ for (i = 0; i < 4; i++)
+ softpipe->blend_color_clamped.color[i] =
+ CLAMP(blend_color->color[i], 0.0f, 1.0f);
+
softpipe->dirty |= SP_NEW_BLEND;
}
--
1.7.3.4
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