Merge pull request #6279 from hypermoist/fix/mesh-draw-short-of-a-primitive

fix(agc): a mesh draw shorter than one primitive draws nothing

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

@@ -812,7 +812,7 @@ std::array<std::uint32_t, 4> MeshIndexBufferDescriptor(const Pm4::DrawParameters
 MeshArgumentRules MeshArgumentRulesFor(const Context& context, const ShaderRecompiler::MeshConfiguration& mesh, std::uint32_t indexCount) {
     const auto inputSize = mesh.inputPrimitive == 1 ? 1u : mesh.inputPrimitive == 2 ? 2u : 3u;
     const auto step = mesh.inputPrimitive == 5 || mesh.inputPrimitive == 6 ? 1u : inputSize;
-    Require(mesh.primitivesPerGroup != 0, "mesh draw contains no complete primitive");
+    Require(mesh.primitivesPerGroup != 0, "mesh pipeline groups no primitive (zero primitives per group)");
     return {indexCount, inputSize, step, mesh.primitivesPerGroup, context.meshLimits.maxMeshWorkGroupCount[0], context.meshLimits.maxMeshWorkGroupCount[1], context.meshLimits.maxMeshWorkGroupTotalCount};
 }
 
@@ -1083,8 +1083,12 @@ DrawInputs prepareDrawInputs(const Context& context, const State& state, const P
         Require(context.meshShader, "device does not support mesh shaders");
         const auto& mesh = *state.stages.mesh;
         const auto inputSize = mesh.inputPrimitive == 1 ? 1u : mesh.inputPrimitive == 2 ? 2u : 3u;
-        Require(draw.indexCount >= inputSize && mesh.primitivesPerGroup != 0, "mesh draw contains no complete primitive");
+        Require(mesh.primitivesPerGroup != 0, "mesh pipeline groups no primitive (zero primitives per group)");
         Require(((state.stages.registerValue >> 19u) & 3u) == 0 || !draw.indexed, "indexed fast-launch draws are unsupported");
+        if (args == nullptr && draw.indexCount < inputSize) {
+            inputs.nothing = true;
+            return inputs;
+        }
         if (args == nullptr) {
             const auto step = mesh.inputPrimitive == 5 || mesh.inputPrimitive == 6 ? 1u : inputSize;
             const auto primitives = (draw.indexCount - inputSize) / step + 1u;

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

@@ -386,6 +386,14 @@ int main() {
         }
         Require(fastLaunchIndexedRefused, "an indexed fast-launch draw was drawn");
 
+        for (const bool indexed : {true, false}) {
+            ClearPixels();
+            DrawMesh(device, {SmallSubgroup, {indexed ? reinterpret_cast<std::uintptr_t>(Indices.data()) : 0u, 2u, indexed ? 2u : 0u, 1, 0, indexed}, VertexBufferDescriptor(indexed ? Scrambled.data() : Ordered.data(), static_cast<std::uint32_t>(Ordered.size()))});
+            for (std::uint32_t triangle = 0; triangle < Triangles; ++triangle) {
+                Require(PixelIs(CellPixel(triangle), Background), std::string(indexed ? "indexed" : "non-indexed") + " triangle-list draw of two vertices drew triangle " + std::to_string(triangle) + ", pixel " + PixelText(CellPixel(triangle)));
+            }
+        }
+
         ClearPixels();
         auto lineSubgroup = FastLaunchSubgroup;
         lineSubgroup.maxPrimitives = 2u;