[Mesa-dev] [PATCH 2/2] svga: implement MSAA alpha_to_one feature
Roland Scheidegger
sroland at vmware.com
Tue Jul 25 05:59:44 UTC 2017
Reviewed-by: Roland Scheidegger <sroland at vmware.com>
Am 25.07.2017 um 05:05 schrieb Brian Paul:
> The device doesn't directly support this feature so we implement it with
> additional shader code which sets the color output(s) w component to
> 1.0 (or max_int or max_uint).
>
> Fixes 16 Piglit ext_framebuffer_multisample/*alpha-to-one* tests.
>
> v2: only support unorm/float buffers, not int/uint, per Roland.
> ---
> src/gallium/drivers/svga/svga_context.h | 1 +
> src/gallium/drivers/svga/svga_pipe_blend.c | 1 +
> src/gallium/drivers/svga/svga_shader.h | 1 +
> src/gallium/drivers/svga/svga_state_fs.c | 3 +++
> src/gallium/drivers/svga/svga_tgsi_vgpu10.c | 41 ++++++++++++++++++++++++++++-
> 5 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/src/gallium/drivers/svga/svga_context.h b/src/gallium/drivers/svga/svga_context.h
> index d0306c0..0d695a6 100644
> --- a/src/gallium/drivers/svga/svga_context.h
> +++ b/src/gallium/drivers/svga/svga_context.h
> @@ -106,6 +106,7 @@ struct svga_blend_state {
> unsigned need_white_fragments:1;
> unsigned independent_blend_enable:1;
> unsigned alpha_to_coverage:1;
> + unsigned alpha_to_one:1;
> unsigned blend_color_alpha:1; /**< set blend color to alpha value */
>
> /** Per-render target state */
> diff --git a/src/gallium/drivers/svga/svga_pipe_blend.c b/src/gallium/drivers/svga/svga_pipe_blend.c
> index 408e175..a29fbd3 100644
> --- a/src/gallium/drivers/svga/svga_pipe_blend.c
> +++ b/src/gallium/drivers/svga/svga_pipe_blend.c
> @@ -331,6 +331,7 @@ svga_create_blend_state(struct pipe_context *pipe,
> blend->independent_blend_enable = templ->independent_blend_enable;
>
> blend->alpha_to_coverage = templ->alpha_to_coverage;
> + blend->alpha_to_one = templ->alpha_to_one;
>
> if (svga_have_vgpu10(svga)) {
> define_blend_state_object(svga, blend);
> diff --git a/src/gallium/drivers/svga/svga_shader.h b/src/gallium/drivers/svga/svga_shader.h
> index a594d12..dc462c9 100644
> --- a/src/gallium/drivers/svga/svga_shader.h
> +++ b/src/gallium/drivers/svga/svga_shader.h
> @@ -77,6 +77,7 @@ struct svga_compile_key
> unsigned light_twoside:1;
> unsigned front_ccw:1;
> unsigned white_fragments:1;
> + unsigned alpha_to_one:1;
> unsigned flatshade:1;
> unsigned pstipple:1;
> unsigned alpha_func:4; /**< SVGA3D_CMP_x */
> diff --git a/src/gallium/drivers/svga/svga_state_fs.c b/src/gallium/drivers/svga/svga_state_fs.c
> index bf45216..5e56899 100644
> --- a/src/gallium/drivers/svga/svga_state_fs.c
> +++ b/src/gallium/drivers/svga/svga_state_fs.c
> @@ -25,6 +25,7 @@
>
> #include "util/u_inlines.h"
> #include "pipe/p_defines.h"
> +#include "util/u_format.h"
> #include "util/u_math.h"
> #include "util/u_memory.h"
> #include "util/u_bitmask.h"
> @@ -234,6 +235,8 @@ make_fs_key(const struct svga_context *svga,
> */
> key->fs.white_fragments = svga->curr.blend->need_white_fragments;
>
> + key->fs.alpha_to_one = svga->curr.blend->alpha_to_one;
> +
> #ifdef DEBUG
> /*
> * We expect a consistent set of samplers and sampler views.
> diff --git a/src/gallium/drivers/svga/svga_tgsi_vgpu10.c b/src/gallium/drivers/svga/svga_tgsi_vgpu10.c
> index 9f5cd4b..54b473d 100644
> --- a/src/gallium/drivers/svga/svga_tgsi_vgpu10.c
> +++ b/src/gallium/drivers/svga/svga_tgsi_vgpu10.c
> @@ -167,8 +167,8 @@ struct svga_shader_emitter_v10
>
> /* For fragment shaders only */
> struct {
> - /* apha test */
> unsigned color_out_index[PIPE_MAX_COLOR_BUFS]; /**< the real color output regs */
> + unsigned num_color_outputs;
> unsigned color_tmp_index; /**< fake/temp color output reg */
> unsigned alpha_ref_index; /**< immediate constant for alpha ref */
>
> @@ -2499,6 +2499,9 @@ emit_output_declarations(struct svga_shader_emitter_v10 *emit)
>
> emit->fs.color_out_index[semantic_index] = index;
>
> + emit->fs.num_color_outputs = MAX2(emit->fs.num_color_outputs,
> + index + 1);
> +
> /* The semantic index is the shader's color output/buffer index */
> emit_output_declaration(emit,
> VGPU10_OPCODE_DCL_OUTPUT, semantic_index,
> @@ -2521,6 +2524,9 @@ emit_output_declarations(struct svga_shader_emitter_v10 *emit)
> VGPU10_OPERAND_4_COMPONENT_MASK_ALL);
> emit->info.output_semantic_index[idx] = j;
> }
> +
> + emit->fs.num_color_outputs =
> + emit->key.fs.write_color0_to_n_cbufs;
> }
> }
> else {
> @@ -6378,6 +6384,36 @@ emit_pre_helpers(struct svga_shader_emitter_v10 *emit)
>
>
> /**
> + * The device has no direct support for the pipe_blend_state::alpha_to_one
> + * option so we implement it here with shader code.
> + */
> +static void
> +emit_alpha_to_one_instructions(struct svga_shader_emitter_v10 *emit,
> + unsigned fs_color_tmp_index)
> +{
> + struct tgsi_full_src_register one = make_immediate_reg_float(emit, 1.0f);
> + unsigned i;
> +
> + for (i = 0; i < emit->fs.num_color_outputs; i++) {
> + struct tgsi_full_dst_register color_dst;
> +
> + if (fs_color_tmp_index != INVALID_INDEX && i == 0) {
> + /* write to the temp color register */
> + color_dst = make_dst_temp_reg(fs_color_tmp_index);
> + }
> + else {
> + /* write directly to the color[i] output */
> + color_dst = make_dst_output_reg(emit->fs.color_out_index[i]);
> + }
> +
> + color_dst = writemask_dst(&color_dst, TGSI_WRITEMASK_W);
> +
> + emit_instruction_op1(emit, VGPU10_OPCODE_MOV, &color_dst, &one, FALSE);
> + }
> +}
> +
> +
> +/**
> * Emit alpha test code. This compares TEMP[fs_color_tmp_index].w
> * against the alpha reference value and discards the fragment if the
> * comparison fails.
> @@ -6494,6 +6530,9 @@ emit_post_helpers(struct svga_shader_emitter_v10 *emit)
> */
> emit->fs.color_tmp_index = INVALID_INDEX;
>
> + if (emit->key.fs.alpha_to_one) {
> + emit_alpha_to_one_instructions(emit, fs_color_tmp_index);
> + }
> if (emit->key.fs.alpha_func != SVGA3D_CMP_ALWAYS) {
> emit_alpha_test_instructions(emit, fs_color_tmp_index);
> }
>
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