From a92e5f7cf63d496ad7830b5cea4bbab287c25b8e Mon Sep 17 00:00:00 2001 From: Anuj Phogat Date: Mon, 6 Jan 2014 13:59:18 -0800 Subject: [PATCH] i965: Use sample barycentric coordinates with per sample shading Current implementation of arb_sample_shading doesn't set 'Barycentric Interpolation Mode' correctly. We use pixel barycentric coordinates for per sample shading. Instead we should select perspective sample or non-perspective sample barycentric coordinates. It also enables using sample barycentric coordinates in case of a fragment shader variable declared with 'sample' qualifier. e.g. sample in vec4 pos; A piglit test to verify the implementation has been posted on piglit mailing list for review. V2: Do not interpolate all the 'in' variables at sample position if fragment shader uses 'sample' qualifier with one of them. For example we have a fragment shader: #version 330 #extension ARB_gpu_shader5: require sample in vec4 a; in vec4 b; main() { ... } Only 'a' should be sampled at sample location, not 'b'. Cc: mesa-stable@lists.freedesktop.org Signed-off-by: Anuj Phogat Reviewed-by: Chris Forbes --- src/mesa/drivers/dri/i965/brw_fs.cpp | 13 ++++++++++--- src/mesa/drivers/dri/i965/brw_fs.h | 2 +- src/mesa/drivers/dri/i965/brw_wm.c | 20 ++++++++++++++++++-- src/mesa/drivers/dri/i965/brw_wm.h | 1 + 4 files changed, 30 insertions(+), 6 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 78ddf0d99cf..430a530d242 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -998,7 +998,7 @@ fs_visitor::emit_fragcoord_interpolation(ir_variable *ir) fs_inst * fs_visitor::emit_linterp(const fs_reg &attr, const fs_reg &interp, glsl_interp_qualifier interpolation_mode, - bool is_centroid) + bool is_centroid, bool is_sample) { brw_wm_barycentric_interp_mode barycoord_mode; if (brw->gen >= 6) { @@ -1007,6 +1007,11 @@ fs_visitor::emit_linterp(const fs_reg &attr, const fs_reg &interp, barycoord_mode = BRW_WM_PERSPECTIVE_CENTROID_BARYCENTRIC; else barycoord_mode = BRW_WM_NONPERSPECTIVE_CENTROID_BARYCENTRIC; + } else if (is_sample) { + if (interpolation_mode == INTERP_QUALIFIER_SMOOTH) + barycoord_mode = BRW_WM_PERSPECTIVE_SAMPLE_BARYCENTRIC; + else + barycoord_mode = BRW_WM_NONPERSPECTIVE_SAMPLE_BARYCENTRIC; } else { if (interpolation_mode == INTERP_QUALIFIER_SMOOTH) barycoord_mode = BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC; @@ -1084,7 +1089,8 @@ fs_visitor::emit_general_interpolation(ir_variable *ir) */ struct brw_reg interp = interp_reg(location, k); emit_linterp(attr, fs_reg(interp), interpolation_mode, - ir->data.centroid); + ir->data.centroid, + ir->data.sample || c->key.persample_shading); if (brw->needs_unlit_centroid_workaround && ir->data.centroid) { /* Get the pixel/sample mask into f0 so that we know * which pixels are lit. Then, for each channel that is @@ -1093,7 +1099,8 @@ fs_visitor::emit_general_interpolation(ir_variable *ir) */ emit(FS_OPCODE_MOV_DISPATCH_TO_FLAGS); fs_inst *inst = emit_linterp(attr, fs_reg(interp), - interpolation_mode, false); + interpolation_mode, + false, false); inst->predicate = BRW_PREDICATE_NORMAL; inst->predicate_inverse = true; } diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h index f493784012b..a9039088a6e 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.h +++ b/src/mesa/drivers/dri/i965/brw_fs.h @@ -340,7 +340,7 @@ public: fs_reg *emit_fragcoord_interpolation(ir_variable *ir); fs_inst *emit_linterp(const fs_reg &attr, const fs_reg &interp, glsl_interp_qualifier interpolation_mode, - bool is_centroid); + bool is_centroid, bool is_sample); fs_reg *emit_frontfacing_interpolation(ir_variable *ir); fs_reg *emit_samplepos_setup(ir_variable *ir); fs_reg *emit_sampleid_setup(ir_variable *ir); diff --git a/src/mesa/drivers/dri/i965/brw_wm.c b/src/mesa/drivers/dri/i965/brw_wm.c index 0a308862c47..a6b558fd6a2 100644 --- a/src/mesa/drivers/dri/i965/brw_wm.c +++ b/src/mesa/drivers/dri/i965/brw_wm.c @@ -49,6 +49,7 @@ static unsigned brw_compute_barycentric_interp_modes(struct brw_context *brw, bool shade_model_flat, + bool persample_shading, const struct gl_fragment_program *fprog) { unsigned barycentric_interp_modes = 0; @@ -62,6 +63,8 @@ brw_compute_barycentric_interp_modes(struct brw_context *brw, enum glsl_interp_qualifier interp_qualifier = fprog->InterpQualifier[attr]; bool is_centroid = fprog->IsCentroid & BITFIELD64_BIT(attr); + bool is_sample = (fprog->IsSample & BITFIELD64_BIT(attr)) || + persample_shading; bool is_gl_Color = attr == VARYING_SLOT_COL0 || attr == VARYING_SLOT_COL1; /* Ignore unused inputs. */ @@ -82,8 +85,12 @@ brw_compute_barycentric_interp_modes(struct brw_context *brw, if (is_centroid) { barycentric_interp_modes |= 1 << BRW_WM_NONPERSPECTIVE_CENTROID_BARYCENTRIC; + } else if (is_sample) { + barycentric_interp_modes |= + 1 << BRW_WM_NONPERSPECTIVE_SAMPLE_BARYCENTRIC; } - if (!is_centroid || brw->needs_unlit_centroid_workaround) { + if ((!is_centroid && !is_sample) || + brw->needs_unlit_centroid_workaround) { barycentric_interp_modes |= 1 << BRW_WM_NONPERSPECTIVE_PIXEL_BARYCENTRIC; } @@ -93,8 +100,12 @@ brw_compute_barycentric_interp_modes(struct brw_context *brw, if (is_centroid) { barycentric_interp_modes |= 1 << BRW_WM_PERSPECTIVE_CENTROID_BARYCENTRIC; + } else if (is_sample) { + barycentric_interp_modes |= + 1 << BRW_WM_PERSPECTIVE_SAMPLE_BARYCENTRIC; } - if (!is_centroid || brw->needs_unlit_centroid_workaround) { + if ((!is_centroid && !is_sample) || + brw->needs_unlit_centroid_workaround) { barycentric_interp_modes |= 1 << BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC; } @@ -171,6 +182,7 @@ bool do_wm_prog(struct brw_context *brw, c->prog_data.barycentric_interp_modes = brw_compute_barycentric_interp_modes(brw, c->key.flat_shade, + c->key.persample_shading, &fp->program); program = brw_wm_fs_emit(brw, c, &fp->program, prog, &program_size); @@ -503,6 +515,10 @@ static void brw_wm_populate_key( struct brw_context *brw, (ctx->Multisample.SampleAlphaToCoverage || ctx->Color.AlphaEnabled); /* _NEW_BUFFERS _NEW_MULTISAMPLE */ + /* Ignore sample qualifier while computing this flag. */ + key->persample_shading = + _mesa_get_min_invocations_per_fragment(ctx, &fp->program, true) > 1; + key->compute_pos_offset = _mesa_get_min_invocations_per_fragment(ctx, &fp->program, false) > 1 && fp->program.Base.SystemValuesRead & SYSTEM_BIT_SAMPLE_POS; diff --git a/src/mesa/drivers/dri/i965/brw_wm.h b/src/mesa/drivers/dri/i965/brw_wm.h index 211db0bdd2b..14a4b8bb5a6 100644 --- a/src/mesa/drivers/dri/i965/brw_wm.h +++ b/src/mesa/drivers/dri/i965/brw_wm.h @@ -61,6 +61,7 @@ struct brw_wm_prog_key { uint8_t iz_lookup; GLuint stats_wm:1; GLuint flat_shade:1; + GLuint persample_shading:1; GLuint nr_color_regions:5; GLuint replicate_alpha:1; GLuint render_to_fbo:1; -- 2.30.2