[Mesa-dev] [PATCH 2/6] meta: Add support for doing multisample resolves.
Eric Anholt
eric at anholt.net
Wed Feb 19 17:30:19 PST 2014
Note that this doesn't handle GL_EXT_multisample_scaled_blit yet. The
i965 code for that extension bakes in knowledge of the sample positions
(well, knowledge of the sample positions aligned to a lower-resolution
grid), which we would have to do at runtime somehow for meta.
---
src/mesa/drivers/common/meta.h | 7 ++
src/mesa/drivers/common/meta_blit.c | 202 +++++++++++++++++++++++++++++++++---
2 files changed, 197 insertions(+), 12 deletions(-)
diff --git a/src/mesa/drivers/common/meta.h b/src/mesa/drivers/common/meta.h
index 822bfa1..5d79253 100644
--- a/src/mesa/drivers/common/meta.h
+++ b/src/mesa/drivers/common/meta.h
@@ -221,6 +221,12 @@ struct blit_shader_table {
struct blit_shader sampler_cubemap_array;
};
+enum blit_msaa_shader {
+ BLIT_MSAA_SHADER_2D_MULTISAMPLE,
+ BLIT_MSAA_SHADER_2D_MULTISAMPLE_DEPTH,
+ BLIT_MSAA_SHADER_COUNT,
+};
+
/**
* State for glBlitFramebufer()
*/
@@ -230,6 +236,7 @@ struct blit_state
GLuint VBO;
GLuint DepthFP;
struct blit_shader_table shaders;
+ GLuint msaa_shaders[BLIT_MSAA_SHADER_COUNT];
struct temp_texture depthTex;
};
diff --git a/src/mesa/drivers/common/meta_blit.c b/src/mesa/drivers/common/meta_blit.c
index a2b284b..be91247 100644
--- a/src/mesa/drivers/common/meta_blit.c
+++ b/src/mesa/drivers/common/meta_blit.c
@@ -31,6 +31,7 @@
#include "main/condrender.h"
#include "main/depth.h"
#include "main/enable.h"
+#include "main/enums.h"
#include "main/fbobject.h"
#include "main/macros.h"
#include "main/matrix.h"
@@ -81,8 +82,158 @@ init_blit_depth_pixels(struct gl_context *ctx)
}
static void
+setup_glsl_msaa_blit_shader(struct gl_context *ctx,
+ struct blit_state *blit,
+ struct gl_renderbuffer *src_rb,
+ GLenum target)
+{
+ const char *vs_source;
+ char *fs_source;
+ GLuint vs, fs;
+ void *mem_ctx;
+ enum blit_msaa_shader shader_index;
+ const char *samplers[] = {
+ [BLIT_MSAA_SHADER_2D_MULTISAMPLE] = "sampler2DMS",
+ };
+
+ 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;
+ } else {
+ shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE;
+ }
+ break;
+ default:
+ _mesa_problem(ctx, "Unkown texture target %s\n",
+ _mesa_lookup_enum_by_nr(target));
+ shader_index = BLIT_MSAA_SHADER_2D_MULTISAMPLE;
+ }
+
+ if (blit->msaa_shaders[shader_index]) {
+ _mesa_UseProgram(blit->msaa_shaders[shader_index]);
+ return;
+ }
+
+ 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.
+ */
+ vs_source = ralloc_asprintf(mem_ctx,
+ "#version 130\n"
+ "in vec2 position;\n"
+ "in vec2 textureCoords;\n"
+ "out vec2 texCoords;\n"
+ "void main()\n"
+ "{\n"
+ " texCoords = textureCoords;\n"
+ " gl_Position = vec4(position, 0.0, 1.0);\n"
+ "}\n");
+ fs_source = ralloc_asprintf(mem_ctx,
+ "#version 130\n"
+ "#extension GL_ARB_texture_multisample : enable\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;
+ /* You can create 2D_MULTISAMPLE textures with 0 sample count (meaning 1
+ * sample). Yes, this is ridiculous.
+ */
+ int samples = MAX2(src_rb->NumSamples, 1);
+
+ /* 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) {
+ 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);
+
+ vs_source = ralloc_asprintf(mem_ctx,
+ "#version 130\n"
+ "in vec2 position;\n"
+ "in vec2 textureCoords;\n"
+ "out vec2 texCoords;\n"
+ "void main()\n"
+ "{\n"
+ " texCoords = textureCoords;\n"
+ " gl_Position = vec4(position, 0.0, 1.0);\n"
+ "}\n");
+ fs_source = ralloc_asprintf(mem_ctx,
+ "#version 130\n"
+ "#extension GL_ARB_texture_multisample : enable\n"
+ "uniform %s texSampler;\n"
+ "in vec2 texCoords;\n"
+ "out vec4 out_color;\n"
+ "\n"
+ "void main()\n"
+ "{\n"
+ "%s\n" /* sample_resolve */
+ "}\n",
+ samplers[shader_index],
+ sample_resolve);
+ }
+
+ vs = _mesa_meta_compile_shader_with_debug(ctx, GL_VERTEX_SHADER, vs_source);
+ fs = _mesa_meta_compile_shader_with_debug(ctx, GL_FRAGMENT_SHADER, fs_source);
+
+ blit->msaa_shaders[shader_index] = _mesa_CreateProgramObjectARB();
+ _mesa_AttachShader(blit->msaa_shaders[shader_index], fs);
+ _mesa_DeleteObjectARB(fs);
+ _mesa_AttachShader(blit->msaa_shaders[shader_index], vs);
+ _mesa_DeleteObjectARB(vs);
+ _mesa_BindAttribLocation(blit->msaa_shaders[shader_index], 0, "position");
+ _mesa_BindAttribLocation(blit->msaa_shaders[shader_index], 1, "texcoords");
+ _mesa_meta_link_program_with_debug(ctx, blit->msaa_shaders[shader_index]);
+ ralloc_free(mem_ctx);
+
+ _mesa_UseProgram(blit->msaa_shaders[shader_index]);
+}
+
+static void
setup_glsl_blit_framebuffer(struct gl_context *ctx,
struct blit_state *blit,
+ struct gl_renderbuffer *src_rb,
GLenum target)
{
/* target = GL_TEXTURE_RECTANGLE is not supported in GLES 3.0 */
@@ -90,7 +241,11 @@ setup_glsl_blit_framebuffer(struct gl_context *ctx,
_mesa_meta_setup_vertex_objects(&blit->VAO, &blit->VBO, true, 2, 2, 0);
- _mesa_meta_setup_blit_shader(ctx, target, &blit->shaders);
+ if (target == GL_TEXTURE_2D_MULTISAMPLE) {
+ setup_glsl_msaa_blit_shader(ctx, blit, src_rb, target);
+ } else {
+ _mesa_meta_setup_blit_shader(ctx, target, &blit->shaders);
+ }
}
/**
@@ -124,6 +279,15 @@ blitframebuffer_texture(struct gl_context *ctx,
ctx->Texture.Unit[ctx->Texture.CurrentUnit].Sampler ?
ctx->Texture.Unit[ctx->Texture.CurrentUnit].Sampler->Name : 0;
GLuint tempTex = 0;
+ struct gl_renderbuffer *rb = readAtt->Renderbuffer;
+
+ if (rb->NumSamples && !ctx->Extensions.ARB_texture_multisample)
+ return false;
+
+ if (filter == GL_SCALED_RESOLVE_FASTEST_EXT ||
+ filter == GL_SCALED_RESOLVE_NICEST_EXT) {
+ filter = GL_LINEAR;
+ }
if (readAtt->Texture) {
/* If there's a texture attached of a type we can handle, then just use
@@ -133,16 +297,25 @@ blitframebuffer_texture(struct gl_context *ctx,
texObj = readAtt->Texture;
target = texObj->Target;
- if (target != GL_TEXTURE_2D && target != GL_TEXTURE_RECTANGLE_ARB)
+ switch (target) {
+ case GL_TEXTURE_2D:
+ case GL_TEXTURE_RECTANGLE:
+ case GL_TEXTURE_2D_MULTISAMPLE:
+ break;
+ default:
return false;
+ }
} else if (ctx->Driver.BindRenderbufferTexImage) {
/* Otherwise, we need the driver to be able to bind a renderbuffer as
* a texture image.
*/
struct gl_texture_image *texImage;
- struct gl_renderbuffer *rb = readAtt->Renderbuffer;
- target = GL_TEXTURE_2D;
+ if (rb->NumSamples > 1)
+ target = GL_TEXTURE_2D_MULTISAMPLE;
+ else
+ target = GL_TEXTURE_2D;
+
_mesa_GenTextures(1, &tempTex);
_mesa_BindTexture(target, tempTex);
srcLevel = 0;
@@ -174,7 +347,7 @@ blitframebuffer_texture(struct gl_context *ctx,
maxLevelSave = texObj->MaxLevel;
if (glsl_version) {
- setup_glsl_blit_framebuffer(ctx, blit, target);
+ setup_glsl_blit_framebuffer(ctx, blit, rb, target);
}
else {
_mesa_meta_setup_ff_tnl_for_blit(&ctx->Meta->Blit.VAO,
@@ -230,7 +403,8 @@ blitframebuffer_texture(struct gl_context *ctx,
t1 = srcY1 / (float) texImage->Height;
}
else {
- assert(target == GL_TEXTURE_RECTANGLE_ARB);
+ assert(target == GL_TEXTURE_RECTANGLE_ARB ||
+ target == GL_TEXTURE_2D_MULTISAMPLE);
s0 = (float) srcX0;
s1 = (float) srcX1;
t0 = (float) srcY0;
@@ -326,12 +500,15 @@ _mesa_meta_BlitFramebuffer(struct gl_context *ctx,
* texture size, fallback if the source is multisampled. This fallback can
* be removed once Mesa gets support ARB_texture_multisample.
*/
- if (srcW > maxTexSize || srcH > maxTexSize
- || ctx->ReadBuffer->Visual.samples > 0) {
+ if (srcW > maxTexSize || srcH > maxTexSize) {
/* XXX avoid this fallback */
- _swrast_BlitFramebuffer(ctx, srcX0, srcY0, srcX1, srcY1,
- dstX0, dstY0, dstX1, dstY1, mask, filter);
- return;
+ goto fallback;
+ }
+
+ /* Multisample texture blit support requires texture multisample. */
+ if (ctx->ReadBuffer->Visual.samples > 0 &&
+ !ctx->Extensions.ARB_texture_multisample) {
+ goto fallback;
}
/* only scissor effects blit so save/clear all other relevant state */
@@ -368,7 +545,7 @@ _mesa_meta_BlitFramebuffer(struct gl_context *ctx,
* BlitFramebuffer function.
*/
if (use_glsl_version) {
- setup_glsl_blit_framebuffer(ctx, blit, tex->Target);
+ setup_glsl_blit_framebuffer(ctx, blit, NULL, tex->Target);
}
else {
_mesa_meta_setup_ff_tnl_for_blit(&blit->VAO, &blit->VBO, 2);
@@ -492,6 +669,7 @@ _mesa_meta_BlitFramebuffer(struct gl_context *ctx,
_mesa_meta_end(ctx);
+fallback:
if (mask) {
_swrast_BlitFramebuffer(ctx, srcX0, srcY0, srcX1, srcY1,
dstX0, dstY0, dstX1, dstY1, mask, filter);
--
1.9.rc1
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