fix(agc): allow MSAA_ENABLE single-sample rect lists

core/libs/prx/libSceAgcDriver/Graphics/src/State.cpp

@@ -444,7 +444,7 @@ std::string singleSampleMsaaRejection(const QueueState& queue) {
     }
     if (const auto alphaToMask = word(cx, 0x2dc); alphaToMask && (*alphaToMask & 1u) != 0 && !(*alphaToMask == AlphaToCoverageDithered && alphaToCoverageDisabled(cx))) return zeroMessage(0x2dc, *alphaToMask, "MSAA_ENABLE on a single-sample target with alpha-to-coverage");
     if (const auto conservative = word(cx, 0x313); conservative && (*conservative & ~0x001f6000u) != 0) return zeroMessage(0x313, *conservative, "MSAA_ENABLE on a single-sample target with conservative rasterization");
-    return nonTriangleRejection(queue, "MSAA_ENABLE on a single-sample target for primitives other than triangles");
+    return nonTriangleRejection(queue, "MSAA_ENABLE on a single-sample target for primitives other than triangles and rectangles", true);
 }
 
 std::string singleSampleDepthScanRejection(const QueueState& queue) {

core/libs/prx/libSceAgcDriver/tests/Graphics.cpp

@@ -907,18 +907,18 @@ void MsaaEnableSingleSampleTests() {
     queue = enabled();
     queue.context[0x313] = 0x6001;
     refused(queue, "MSAA_ENABLE on a single-sample target with conservative rasterization");
-    for (const auto primitive : {2u, 7u, 17u}) {
+    for (const auto primitive : {2u, 3u}) {
         queue = enabled();
         queue.userConfig[0x242] = primitive;
-        refused(queue, "primitives other than triangles");
+        refused(queue, "primitives other than triangles and rectangles");
     }
     queue = enabled();
     queue.userConfig[0x242] = 1;
-    Require(DrawRejection(queue, false).find("primitives other than triangles") != std::string::npos, "the precheck accepted MSAA_ENABLE on a single-sample target for points");
-    for (const auto primitive : {5u, 6u, 21u}) {
+    Require(DrawRejection(queue, false).find("primitives other than triangles and rectangles") != std::string::npos, "the precheck accepted MSAA_ENABLE on a single-sample target for points");
+    for (const auto primitive : {5u, 6u, 7u, 17u, 21u}) {
         queue = enabled();
         queue.userConfig[0x242] = primitive;
-        Require(DecodeState(queue).samples == 1 && DrawRejection(queue, false).empty(), "MSAA_ENABLE on a single-sample target was refused for a triangle fan, strip or polygon");
+        Require(DecodeState(queue).samples == 1 && DrawRejection(queue, false).empty(), "MSAA_ENABLE on a single-sample target was refused for a filled triangle or rectangle primitive");
     }
     queue = enabled();
     queue.context[0x292] = 7;

docs/dev/debt/libSceAgcDriver.md

@@ -22,7 +22,7 @@
 - [Line-strip geometry output](../../../core/libs/prx/libSceAgcDriver/Graphics/src/State.cpp) (AGC driver) - a geometry program with `VGT_GS_OUT_PRIM_TYPE = 1` (line strip) runs as a mesh shader with `OutputLinesEXT`: each primitive export is one line whose two vertex indices are packed like the three of a triangle, as Mesa's NGG lowering exports line strips (`ac_nir_lower_ngg_gs.c`), and each input primitive gets `VGT_GS_MAX_VERT_OUT - 1` lines where a triangle strip gets `- 2` triangles. A subgroup gets at least `GE_MAX_OUTPUT_PER_SUBGROUP` line slots, because Mesa's lowering exports one primitive, possibly null, per emitted vertex; whether the console's compiler does the same is not known, and triangle strips keep `- 2` per input. A fast-launch subgroup takes its line count from `GE_NGG_SUBGRP_CNTL.PRIM_AMP_FACTOR` as for triangles. Line output counts as lines for the polygon offset decode, as on the vertex path. The lines are drawn 1 pixel wide with Vulkan's default line rasterization, like lines on the vertex path: `PA_SU_LINE_CNTL` is not read, and neither its width nor the console's line rules were measured. Points, rectangle lists, per-stream types and line strips from a vertex program on the mesh path still throw.
 - [Alpha-to-coverage](../../../core/libs/prx/libSceAgcDriver/Graphics/src/State.cpp) (AGC driver) - only `DB_ALPHA_TO_MASK = 0xaa01` is accepted: the enable bit with the four quad offsets at 2 and no `OFFSET_ROUND`, the undithered setting [radeonsi](https://gitlab.freedesktop.org/mesa/mesa/-/blob/bffd91947efc1932da99aca69fc540d6d4201b0c/src/gallium/drivers/radeonsi/si_state.c#L371-L381) programs. Draws are single-sampled, so the pixel shader [writes](../../../core/shader/recompiler/SpirvBackend/src/SpirvModuleEmitter.cpp) `SampleMask` 0 when its MRT0 alpha is below one half or NaN and all ones otherwise, and runs with late fragment tests. That rule was measured on a Radeon 660M (gfx1035, RADV with `RADV_DEBUG=noatocdithering`, which programs the same register) for 0, -0, 0.25, the two floats below one half, one half, the two above, 0.75, 1, 2, -1, both infinities and both NaNs, and is pinned in [AlphaToCoverage.cpp](../../../core/libs/prx/libSceAgcDriver/tests/execution/AlphaToCoverage.cpp); it is not measured on gfx1013. Vulkan's `alphaToCoverageEnable` is not used: the NVIDIA driver 615.78.08 dithers single-sample coverage (an alpha of 0.25 writes half the pixels of an RTX 3050 Laptop target). Other offsets, `OFFSET_ROUND`, a sample-mask export, and an MRT0 that is missing, swizzled, packed or exported without a floating-point alpha throw. A draw without a color target on MRT0 keeps alpha-to-coverage from its MRT0 export, as [radeonsi exports MRT0 as `32_AR` for alpha-to-coverage without a color buffer](https://gitlab.freedesktop.org/mesa/mesa/-/blob/mesa-24.0.0/src/gallium/drivers/radeonsi/si_state_shaders.cpp#L2425-L2431). A draw that enables alpha-to-coverage with no MRT0 export still throws: what the console covers then is not measured. Default dithered `DB_ALPHA_TO_MASK = 0x18701` additionally uses a per-quad sample-mask table [measured on gfx1036](https://github.com/boykopovar/AnyPS5/pull/4451#issuecomment-6124848921) for eight standard samples with FP16_ABGR or 32_ABGR exports; other sample counts, custom locations, EQAA combinations and dithered UNORM16/SNORM16 exports throw. The dithered rule is not measured on gfx1013.
 - [A one-sample target under a multisampled rasterizer without MSAA_ENABLE](../../../core/libs/prx/libSceAgcDriver/Graphics/src/State.cpp) (AGC driver) - `PA_SC_AA_CONFIG.MSAA_NUM_SAMPLES` > 0 with `PA_SC_MODE_CNTL_0.MSAA_ENABLE` clear, one-sample color targets and no depth target, or a one-sample depth target with no color target or one-sample color targets, is drawn as a one-sample draw at the pixel center. Without the bit every sample is taken to be at the pixel center (see the entry for a multisampled target rasterized without MSAA_ENABLE below), and a one-sample target is taken to keep the coverage of sample 0, so a one-sample depth target is tested and written once per pixel with the depth at the pixel center. That is the rule [`VK_AMD_mixed_attachment_samples`](https://github.com/KhronosGroup/Vulkan-Docs/blob/193ebe195f47ffc5004683d1659e71c725658c4d/chapters/fragops.adoc#L2510-L2516) gives a color target with fewer samples than the rasterizer, but Vulkan reaches it only beside a depth or stencil target with the rasterizer's sample count ([VUID-VkGraphicsPipelineCreateInfo-subpass-01505](https://github.com/KhronosGroup/Vulkan-Docs/blob/193ebe195f47ffc5004683d1659e71c725658c4d/chapters/pipelines.adoc#L3033-L3041)), so here it is an analogy, and for a one-sample depth target an extension of it. [shadPS4](https://github.com/shadps4-emu/shadPS4/blob/15abf68c9b52c4b04d094f2837719fdb871021f3/src/video_core/renderer_vulkan/vk_graphics_pipeline.cpp#L127-L128) also rasterizes with the largest sample count of the bound depth and color targets ([L416-L417](https://github.com/shadps4-emu/shadPS4/blob/15abf68c9b52c4b04d094f2837719fdb871021f3/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp#L416-L417), [L477-L480](https://github.com/shadps4-emu/shadPS4/blob/15abf68c9b52c4b04d094f2837719fdb871021f3/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp#L477-L480)), and reads `PA_SC_AA_CONFIG` only for a `SAMPLE_COVERAGE` input ([L174-L177](https://github.com/shadps4-emu/shadPS4/blob/15abf68c9b52c4b04d094f2837719fdb871021f3/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp#L174-L177)). This is not measured on hardware. `PS_ITER_SAMPLE`, an `ANCILLARY` or `SAMPLE_COVERAGE` pixel input and a sample-mask export throw in a pixel program that runs, because what the console gives them under a multisampled configuration is not known; a depth-only draw that skips its pixel program is drawn with the null program, and its `PS_ITER_SAMPLE` and pixel input bits are ignored. Points, lines and alpha-to-coverage throw as for a multisampled target. With a one-sample depth target, `DB_EQAA` Z interpolation (`INTERPOLATE_COMP_Z`, `INTERPOLATE_SRC_Z`) or overrasterization (`OVERRASTERIZATION_AMOUNT`, `ENABLE_POSTZ_OVERRASTERIZATION`) also throws. METAL GEAR SOLID: Peace Walker (PPSA18216) draws a one-sample color target under a 4x configuration this way; the first draw of its opening movie binds a one-sample depth target and no color target under the same configuration.
-- [MSAA_ENABLE on a single-sample target](../../../core/libs/prx/libSceAgcDriver/Graphics/src/State.cpp) (AGC driver) - `PA_SC_MODE_CNTL_0.MSAA_ENABLE` with `PA_SC_AA_CONFIG.MSAA_NUM_SAMPLES = 0` is drawn like the same state without the bit when sample 0 of the four `PA_SC_AA_SAMPLE_LOCS_PIXEL_*_0` registers is at the pixel center and the draw rasterizes filled triangles with alpha-to-coverage and conservative rasterization off. [RADV](https://gitlab.freedesktop.org/mesa/mesa/-/blob/745709a000482a4a24c91faef5c5a40bd653a863/src/amd/vulkan/radv_cmd_buffer.c#L13606-13609) programs this state for one-sample custom sample locations on GFX10 and later, where the bit makes the rasterizer use the programmed location of sample 0 ([061bc615](https://gitlab.freedesktop.org/mesa/mesa/-/commit/061bc6151a11597f720535f00e79a5752e24aff6)); that the bit changes nothing else for such a draw is inferred from that and is not measured on hardware. Other locations of sample 0, absent location registers, points, lines, rectangles, alpha-to-coverage and conservative rasterization throw
+- [MSAA_ENABLE on a single-sample target](../../../core/libs/prx/libSceAgcDriver/Graphics/src/State.cpp) (AGC driver) - `PA_SC_MODE_CNTL_0.MSAA_ENABLE` with `PA_SC_AA_CONFIG.MSAA_NUM_SAMPLES = 0` is drawn like the same state without the bit when sample 0 of the four `PA_SC_AA_SAMPLE_LOCS_PIXEL_*_0` registers is at the pixel center and the draw rasterizes filled triangles or rectangles (`VGT_PRIMITIVE_TYPE` 7 or 17 as well as the triangle types) with alpha-to-coverage and conservative rasterization off. [RADV](https://gitlab.freedesktop.org/mesa/mesa/-/blob/745709a000482a4a24c91faef5c5a40bd653a863/src/amd/vulkan/radv_cmd_buffer.c#L13606-13609) programs this state for one-sample custom sample locations on GFX10 and later, where the bit makes the rasterizer use the programmed location of sample 0 ([061bc615](https://gitlab.freedesktop.org/mesa/mesa/-/commit/061bc6151a11597f720535f00e79a5752e24aff6)); that the bit changes nothing else for such a draw is inferred from that and is not measured on hardware. EA Sports UFC 5 (PPSA03541) reaches a rect-list draw in this state. Other locations of sample 0, absent location registers, points, lines, alpha-to-coverage and conservative rasterization throw
 - [A multisampled target rasterized without MSAA_ENABLE](../../../core/libs/prx/libSceAgcDriver/Graphics/src/State.cpp) (AGC driver) - `PA_SC_AA_CONFIG.MSAA_NUM_SAMPLES` > 0 with `PA_SC_MODE_CNTL_0.MSAA_ENABLE` clear is drawn with the target's sample count and every sample at the pixel center, as a single-sample scan into a multisampled target already is. On GFX10 and later the bit is what makes the rasterizer use the programmed sample locations ([RADV 061bc615](https://gitlab.freedesktop.org/mesa/mesa/-/commit/061bc6151a11597f720535f00e79a5752e24aff6)), and with multisampling disabled GL rasterizes at the pixel center and gives the fragment full coverage, which radeonsi programs by clearing the bit; that the hardware does the same with `MSAA_NUM_SAMPLES` > 0 is inferred from these and is not measured on hardware. A depth target with the same sample count also has every sample at the pixel center, so each depth and stencil sample is tested and written with the depth at the pixel center, as GL allows when multisampling is disabled ([L185-L190](https://github.com/KhronosGroup/OpenGL-Registry/blob/6af574a14089ccfee87efe230ebcdd8742859813/extensions/ARB/ARB_multisample.txt#L185-L190), [L422-L425](https://github.com/KhronosGroup/OpenGL-Registry/blob/6af574a14089ccfee87efe230ebcdd8742859813/extensions/ARB/ARB_multisample.txt#L422-L425)). GL also lets an implementation test only a centermost sample and set every sample from it ([L425-L434](https://github.com/KhronosGroup/OpenGL-Registry/blob/6af574a14089ccfee87efe230ebcdd8742859813/extensions/ARB/ARB_multisample.txt#L425-L434)), which differs when a pixel's stored samples differ; which one the console does, and how its occlusion queries count such a draw, is not measured on hardware. `DB_EQAA` Z interpolation or overrasterization and a sample-mask export with a depth target throw. Points, lines and alpha-to-coverage throw. SONIC SUPERSTARS (PPSA06888) draws such a 2x target, and METAL GEAR SOLID: Peace Walker (PPSA18216) a 4x depth and color pair.
 - [sceAgcDriverGetEqContextId](../../../core/libs/prx/libSceAgcDriver/Eq/src/Query.cpp) (libSceAgcDriver) - returns `ident`: an end-of-pipe interrupt is delivered only to the registration whose id equals the raising queue, so `ident` is that context's id (titles register 0 or 1 for graphics and `0x20 + 8 * pipe + queue` for compute). The console's value is not known; KytyPS5 returns the event's `data`, which it fills with the interrupt's context id, whereas `data` here is the EV_CLEAR trigger count. Other event filters throw
 - [User data registers](../../../core/libs/prx/libSceAgcDriver/Execution/src/Driver/Diagnostics.cpp) (AGC driver) - a `SPI_SHADER_USER_DATA_*` or `COMPUTE_USER_DATA_*` register the title never wrote reads as 0 when a stage's RSRC2 count covers it, as Kyty (zeroed `UserSgprInfo`) and SharpEmu (missing registers read 0) do, and as AMD PAL and Mesa initialize them; the console's value is not confirmed