[Mesa-dev] [PATCH 5/6] meta: Add support for doing MSAA to MSAA blits.
Eric Anholt
eric at anholt.net
Wed Feb 19 17:30:22 PST 2014
These are non-stretched, non-resolving blits, so it's just a matter of
sampling once from our gl_SampleID and storing that to our color/depth.
---
src/mesa/drivers/common/meta.h | 6 +-
src/mesa/drivers/common/meta_blit.c | 147 ++++++++++++++++++++++++------------
2 files changed, 104 insertions(+), 49 deletions(-)
diff --git a/src/mesa/drivers/common/meta.h b/src/mesa/drivers/common/meta.h
index 7d4474e..c7a21fc 100644
--- a/src/mesa/drivers/common/meta.h
+++ b/src/mesa/drivers/common/meta.h
@@ -222,8 +222,10 @@ struct blit_shader_table {
};
enum blit_msaa_shader {
- BLIT_MSAA_SHADER_2D_MULTISAMPLE,
- BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH,
+ BLIT_MSAA_SHADER_2D_MULTISAMPLE_RESOLVE,
+ BLIT_MSAA_SHADER_2D_MULTISAMPLE_COPY,
+ BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH_RESOLVE,
+ BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH_COPY,
BLIT_MSAA_SHADER_COUNT,
};
diff --git a/src/mesa/drivers/common/meta_blit.c b/src/mesa/drivers/common/meta_blit.c
index 65e2692..7f5416d 100644
--- a/src/mesa/drivers/common/meta_blit.c
+++ b/src/mesa/drivers/common/meta_blit.c
@@ -35,6 +35,7 @@
#include "main/fbobject.h"
#include "main/macros.h"
#include "main/matrix.h"
+#include "main/multisample.h"
#include "main/readpix.h"
#include "main/shaderapi.h"
#include "main/texobj.h"
@@ -93,22 +94,45 @@ setup_glsl_msaa_blit_shader(struct gl_context *ctx,
void *mem_ctx;
enum blit_msaa_shader shader_index;
const char *samplers[] = {
- [BLIT_MSAA_SHADER_2D_MULTISAMPLE] = "sampler2DMS",
+ [BLIT_MSAA_SHADER_2D_MULTISAMPLE_RESOLVE] = "sampler2DMS",
+ [BLIT_MSAA_SHADER_2D_MULTISAMPLE_COPY] = "sampler2DMS",
};
+ bool dst_is_msaa = false;
+
+ if (ctx->DrawBuffer->Visual.samples > 1) {
+ /* If you're calling meta_BlitFramebuffer with the destination
+ * multisampled, this is the only path that will work -- swrast and
+ * CopyTexImage won't work on it either.
+ */
+ assert(ctx->Extensions.ARB_sample_shading);
+
+ dst_is_msaa = true;
+
+ /* We need shader invocation per sample, not per pixel */
+ _mesa_set_enable(ctx, GL_MULTISAMPLE, GL_TRUE);
+ _mesa_set_enable(ctx, GL_SAMPLE_SHADING, GL_TRUE);
+ _mesa_MinSampleShading(1.0);
+ }
switch (target) {
case GL_TEXTURE_2D_MULTISAMPLE:
if (src_rb->_BaseFormat == GL_DEPTH_COMPONENT ||
src_rb->_BaseFormat == GL_DEPTH_STENCIL) {
- shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH;
+ if (dst_is_msaa)
+ shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH_COPY;
+ else
+ shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH_RESOLVE;
} else {
- shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE;
+ if (dst_is_msaa)
+ shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE_COPY;
+ else
+ shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE_RESOLVE;
}
break;
default:
_mesa_problem(ctx, "Unkown texture target %s\n",
_mesa_lookup_enum_by_nr(target));
- shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE;
+ shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE_RESOLVE;
}
if (blit->msaa_shaders[shader_index]) {
@@ -118,17 +142,32 @@ setup_glsl_msaa_blit_shader(struct gl_context *ctx,
mem_ctx = ralloc_context(NULL);
- if (shader_index == BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH) {
- /* From the GL 4.3 spec:
- *
- * "If there is a multisample buffer (the value of SAMPLE_BUFFERS is
- * one), then values are obtained from the depth samples in this
- * buffer. It is recommended that the depth value of the centermost
- * sample be used, though implementations may choose any function
- * of the depth sample values at each pixel.
- *
- * We're slacking and instead of choosing centermost, we've got 0.
- */
+ if (shader_index == BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH_RESOLVE ||
+ shader_index == BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH_COPY) {
+ char *sample_index;
+ const char *arb_sample_shading_extension_string;
+
+ if (dst_is_msaa) {
+ arb_sample_shading_extension_string = "#extension GL_ARB_sample_shading : enable";
+ sample_index = "gl_SampleID";
+ } else {
+ /* Don't need that extension, since we're drawing to a single-sampled
+ * destination.
+ */
+ arb_sample_shading_extension_string = "";
+ /* From the GL 4.3 spec:
+ *
+ * "If there is a multisample buffer (the value of SAMPLE_BUFFERS
+ * is one), then values are obtained from the depth samples in
+ * this buffer. It is recommended that the depth value of the
+ * centermost sample be used, though implementations may choose
+ * any function of the depth sample values at each pixel.
+ *
+ * We're slacking and instead of choosing centermost, we've got 0.
+ */
+ sample_index = "0";
+ }
+
vs_source = ralloc_asprintf(mem_ctx,
"#version 130\n"
"in vec2 position;\n"
@@ -142,52 +181,64 @@ setup_glsl_msaa_blit_shader(struct gl_context *ctx,
fs_source = ralloc_asprintf(mem_ctx,
"#version 130\n"
"#extension GL_ARB_texture_multisample : enable\n"
+ "%s\n"
"uniform sampler2DMS texSampler;\n"
"in vec2 texCoords;\n"
"out vec4 out_color;\n"
"\n"
"void main()\n"
"{\n"
- " gl_FragDepth = texelFetch(texSampler, ivec2(texCoords), 0).r;\n"
- "}\n");
- } else if (shader_index == BLIT_MSAA_SHADER_2D_MULTISAMPLE) {
- char *sample_resolve;
+ " gl_FragDepth = texelFetch(texSampler, ivec2(texCoords), %s).r;\n"
+ "}\n",
+ arb_sample_shading_extension_string,
+ sample_index);
+ } else {
/* You can create 2D_MULTISAMPLE textures with 0 sample count (meaning 1
* sample). Yes, this is ridiculous.
*/
int samples = MAX2(src_rb->NumSamples, 1);
+ char *sample_resolve;
+ const char *arb_sample_shading_extension_string;
- /* We're assuming power of two samples for this resolution procedure.
- *
- * To avoid losing any floating point precision if the samples all
- * happen to have the same value, we merge pairs of values at a time (so
- * the floating point exponent just gets increased), rather than doing a
- * naive sum and dividing.
- */
- assert((samples & (samples - 1)) == 0);
- /* Fetch each individual sample. */
- sample_resolve = rzalloc_size(mem_ctx, 1);
- for (int i = 0; i < samples; i++) {
- ralloc_asprintf_append(&sample_resolve,
- " vec4 sample_1_%d = texelFetch(texSampler, ivec2(texCoords), %d);\n",
- i, i);
- }
- /* Now, merge each pair of samples, then each pair of those merges, etc.
- */
- for (int step = 2; step <= samples; step *= 2) {
- for (int i = 0; i < samples; i += step) {
+ if (dst_is_msaa) {
+ arb_sample_shading_extension_string = "#extension GL_ARB_sample_shading : enable";
+ sample_resolve = ralloc_asprintf(mem_ctx, " out_color = texelFetch(texSampler, ivec2(texCoords), gl_SampleID);");
+ } else {
+ arb_sample_shading_extension_string = "";
+
+ /* We're assuming power of two samples for this resolution procedure.
+ *
+ * To avoid losing any floating point precision if the samples all
+ * happen to have the same value, we merge pairs of values at a time
+ * (so the floating point exponent just gets increased), rather than
+ * doing a naive sum and dividing.
+ */
+ assert((samples & (samples - 1)) == 0);
+ /* Fetch each individual sample. */
+ sample_resolve = rzalloc_size(mem_ctx, 1);
+ for (int i = 0; i < samples; i++) {
ralloc_asprintf_append(&sample_resolve,
- "vec4 sample_%d_%d = sample_%d_%d + sample_%d_%d;\n",
- step, i,
- step / 2, i,
- step / 2, i + step / 2);
+ " vec4 sample_1_%d = texelFetch(texSampler, ivec2(texCoords), %d);\n",
+ i, i);
+ }
+ /* Now, merge each pair of samples, then merge each pair of those,
+ * etc.
+ */
+ for (int step = 2; step <= samples; step *= 2) {
+ for (int i = 0; i < samples; i += step) {
+ ralloc_asprintf_append(&sample_resolve,
+ "vec4 sample_%d_%d = sample_%d_%d + sample_%d_%d;\n",
+ step, i,
+ step / 2, i,
+ step / 2, i + step / 2);
+ }
}
- }
- /* Scale the final result. */
- ralloc_asprintf_append(&sample_resolve,
- " out_color = sample_%d_0 / %f;\n",
- samples, (float)samples);
+ /* Scale the final result. */
+ ralloc_asprintf_append(&sample_resolve,
+ " out_color = sample_%d_0 / %f;\n",
+ samples, (float)samples);
+ }
vs_source = ralloc_asprintf(mem_ctx,
"#version 130\n"
@@ -202,6 +253,7 @@ setup_glsl_msaa_blit_shader(struct gl_context *ctx,
fs_source = ralloc_asprintf(mem_ctx,
"#version 130\n"
"#extension GL_ARB_texture_multisample : enable\n"
+ "%s\n"
"uniform %s texSampler;\n"
"in vec2 texCoords;\n"
"out vec4 out_color;\n"
@@ -210,6 +262,7 @@ setup_glsl_msaa_blit_shader(struct gl_context *ctx,
"{\n"
"%s\n" /* sample_resolve */
"}\n",
+ arb_sample_shading_extension_string,
samplers[shader_index],
sample_resolve);
}
--
1.9.rc1
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