<div dir="ltr">On 20 November 2013 01:28, Chris Forbes <<a href="mailto:chrisf@ijw.co.nz" target="_blank">chrisf@ijw.co.nz</a>> wrote: <div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> If I'm reading this right, there is now *always* a GS in the clear program, if the driver can support it -- is this possibly silly, given that most clears will be nonlayered? My understanding is that switching the GS stage on and off carries pretty severe penalties on some hardware. </blockquote><div> </div><div>I'd be curious to hear more about this. I'm not aware of it carrying severe penalties on i965, for example. </div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> It might be that this turns out not to be a factor, if everyone tries to use a better clear path than meta. </blockquote><div> </div><div>I suspect this is the case. i965 uses a blorp-based clear in most circumstances, and only falls back on Meta if that fails for some reason. Gallium-based drivers don't use Meta at all. IIRC, the only other driver that uses Meta is i915, which doesn't support geometry shaders so it won't be affected by these changes. </div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> -- Chris <div><div class="h5"> On Wed, Nov 20, 2013 at 5:47 PM, Paul Berry <<a href="mailto:stereotype441@gmail.com">stereotype441@gmail.com</a>> wrote: > From section 4.4.7 (Layered Framebuffers) of the GLSL 3.2 spec: > > When the Clear or ClearBuffer* commands are used to clear a > layered framebuffer attachment, all layers of the attachment are > cleared. > > This patch fixes meta clears to properly clear all layers of a layered > framebuffer attachment. We accomplish this by adding a geometry > shader to the meta clear program which sets gl_Layer to a uniform > value. When clearing a layered framebuffer, we execute in a loop, > setting the uniform to point to each layer in turn. > > Cc: "10.0" <<a href="mailto:mesa-stable@lists.freedesktop.org">mesa-stable@lists.freedesktop.org</a>> > --- > src/mesa/drivers/common/meta.c | 51 +++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 48 insertions(+), 3 deletions(-) > > diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c > index 99b02ba..a6d5098 100644 > --- a/src/mesa/drivers/common/meta.c > +++ b/src/mesa/drivers/common/meta.c > @@ -241,9 +241,11 @@ struct clear_state > GLuint VBO; > GLuint ShaderProg; > GLint ColorLocation; > + GLint LayerLocation; > > GLuint IntegerShaderProg; > GLint IntegerColorLocation; > + GLint IntegerLayerLocation; > }; > > > @@ -2145,6 +2147,19 @@ meta_glsl_clear_init(struct gl_context *ctx, struct clear_state *clear) > "{\n" > " gl_Position = position;\n" > "}\n"; > + const char *gs_source = > + "#version 150\n" > + "layout(triangles) in;\n" > + "layout(triangle_strip, max_vertices = 4) out;\n" > + "uniform int layer;\n" > + "void main()\n" > + "{\n" > + " for (int i = 0; i < 3; i++) {\n" > + " gl_Layer = layer;\n" > + " gl_Position = gl_in[i].gl_Position;\n" > + " EmitVertex();\n" > + " }\n" > + "}\n"; > const char *fs_source = > "#ifdef GL_ES\n" > "precision highp float;\n" > @@ -2154,7 +2169,7 @@ meta_glsl_clear_init(struct gl_context *ctx, struct clear_state *clear) > "{\n" > " gl_FragColor = color;\n" > "}\n"; > - GLuint vs, fs; > + GLuint vs, gs = 0, fs; > bool has_integer_textures; > > if (clear->ArrayObj != 0) > @@ -2176,6 +2191,12 @@ meta_glsl_clear_init(struct gl_context *ctx, struct clear_state *clear) > _mesa_ShaderSource(vs, 1, &vs_source, NULL); > _mesa_CompileShader(vs); > > + if (_mesa_has_geometry_shaders(ctx)) { > + gs = _mesa_CreateShaderObjectARB(GL_GEOMETRY_SHADER); > + _mesa_ShaderSource(gs, 1, &gs_source, NULL); > + _mesa_CompileShader(gs); > + } > + > fs = _mesa_CreateShaderObjectARB(GL_FRAGMENT_SHADER); > _mesa_ShaderSource(fs, 1, &fs_source, NULL); > _mesa_CompileShader(fs); > @@ -2183,6 +2204,8 @@ meta_glsl_clear_init(struct gl_context *ctx, struct clear_state *clear) > clear->ShaderProg = _mesa_CreateProgramObjectARB(); > _mesa_AttachShader(clear->ShaderProg, fs); > _mesa_DeleteObjectARB(fs); > + if (gs != 0) > + _mesa_AttachShader(clear->ShaderProg, gs); > _mesa_AttachShader(clear->ShaderProg, vs); > _mesa_DeleteObjectARB(vs); > _mesa_BindAttribLocation(clear->ShaderProg, 0, "position"); > @@ -2190,6 +2213,10 @@ meta_glsl_clear_init(struct gl_context *ctx, struct clear_state *clear) > > clear->ColorLocation = _mesa_GetUniformLocation(clear->ShaderProg, > "color"); > + if (gs != 0) { > + clear->LayerLocation = _mesa_GetUniformLocation(clear->ShaderProg, > + "layer"); > + } > > has_integer_textures = _mesa_is_gles3(ctx) || > (_mesa_is_desktop_gl(ctx) && ctx->Const.GLSLVersion >= 130); > @@ -2227,6 +2254,8 @@ meta_glsl_clear_init(struct gl_context *ctx, struct clear_state *clear) > clear->IntegerShaderProg = _mesa_CreateProgramObjectARB(); > _mesa_AttachShader(clear->IntegerShaderProg, fs); > _mesa_DeleteObjectARB(fs); > + if (gs != 0) > + _mesa_AttachShader(clear->IntegerShaderProg, gs); > _mesa_AttachShader(clear->IntegerShaderProg, vs); > _mesa_DeleteObjectARB(vs); > _mesa_BindAttribLocation(clear->IntegerShaderProg, 0, "position"); > @@ -2240,7 +2269,13 @@ meta_glsl_clear_init(struct gl_context *ctx, struct clear_state *clear) > > clear->IntegerColorLocation = > _mesa_GetUniformLocation(clear->IntegerShaderProg, "color"); > + if (gs != 0) { > + clear->IntegerLayerLocation = > + _mesa_GetUniformLocation(clear->IntegerShaderProg, "layer"); > + } > } > + if (gs != 0) > + _mesa_DeleteObjectARB(gs); > } > > static void > @@ -2371,8 +2406,18 @@ _mesa_meta_glsl_Clear(struct gl_context *ctx, GLbitfield buffers) > _mesa_BufferData(GL_ARRAY_BUFFER_ARB, sizeof(verts), verts, > GL_DYNAMIC_DRAW_ARB); > > - /* draw quad */ > - _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4); > + /* draw quad(s) */ > + if (fb->Layered) { > + for (unsigned layer = 0; layer < fb->NumLayers; layer++) { > + if (fb->_IntegerColor) > + _mesa_Uniform1i(clear->IntegerLayerLocation, layer); > + else > + _mesa_Uniform1i(clear->LayerLocation, layer); > + _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4); > + } > + } else { > + _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4); > + } > > _mesa_meta_end(ctx); > } > -- > 1.8.4.2 > </div></div>> _______________________________________________ > mesa-dev mailing list > <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a> > <a href="http://lists.freedesktop.org/mailman/listinfo/mesa-dev" target="_blank">http://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> </blockquote></div> </div></div>