Cache valid draw modes for draw calls.

src/libANGLE/Context.cpp

@@ -260,17 +260,17 @@ void LimitCap(CapT *cap, MaxT maximum)
 }
 
 constexpr angle::PackedEnumMap<gl::PrimitiveMode, GLsizei> kMinimumPrimitiveCounts = {{
-    /* Points */ 1,
-    /* Lines */ 2,
-    /* LineLoop */ 2,
-    /* LineStrip */ 2,
-    /* Triangles */ 3,
-    /* TriangleStrip */ 3,
-    /* TriangleFan */ 3,
-    /* LinesAdjacency */ 2,
-    /* LineStripAdjacency */ 2,
-    /* TrianglesAdjacency */ 3,
-    /* TriangleStripAdjacency */ 3,
+    1, /* Points */
+    2, /* Lines */
+    2, /* LineLoop */
+    2, /* LineStrip */
+    3, /* Triangles */
+    3, /* TriangleStrip */
+    3, /* TriangleFan */
+    2, /* LinesAdjacency */
+    2, /* LineStripAdjacency */
+    3, /* TrianglesAdjacency */
+    3, /* TriangleStripAdjacency */
 }};
 // Indices above are code-gen'd so make sure they don't change
 //  if any of these static asserts are hit, must update kMinimumPrimitiveCounts abouve
@@ -7893,6 +7893,7 @@ void StateCache::onProgramExecutableChange(Context *context)
     updateActiveAttribsMask(context);
     updateVertexElementLimits(context);
     updateBasicDrawStatesError();
+    updateValidDrawModes(context);
 }
 
 void StateCache::onVertexArrayFormatChange(Context *context)
@@ -7967,4 +7968,47 @@ void StateCache::onBufferBindingChange(Context *context)
 {
     updateBasicDrawStatesError();
 }
+
+void StateCache::updateValidDrawModes(Context *context)
+{
+    Program *program = context->getGLState().getProgram();
+    if (!program || !program->hasLinkedShaderStage(ShaderType::Geometry))
+    {
+        mCachedValidDrawModes = {{
+            true,  /* Points */
+            true,  /* Lines */
+            true,  /* LineLoop */
+            true,  /* LineStrip */
+            true,  /* Triangles */
+            true,  /* TriangleStrip */
+            true,  /* TriangleFan */
+            false, /* LinesAdjacency */
+            false, /* LineStripAdjacency */
+            false, /* TrianglesAdjacency */
+            false, /* TriangleStripAdjacency */
+            false, /* InvalidEnum */
+        }};
+    }
+    else
+    {
+        ASSERT(program && program->hasLinkedShaderStage(ShaderType::Geometry));
+
+        PrimitiveMode gsMode = program->getGeometryShaderInputPrimitiveType();
+
+        mCachedValidDrawModes = {{
+            gsMode == PrimitiveMode::Points,             /* Points */
+            gsMode == PrimitiveMode::Lines,              /* Lines */
+            gsMode == PrimitiveMode::Lines,              /* LineLoop */
+            gsMode == PrimitiveMode::Lines,              /* LineStrip */
+            gsMode == PrimitiveMode::Triangles,          /* Triangles */
+            gsMode == PrimitiveMode::Triangles,          /* TriangleStrip */
+            gsMode == PrimitiveMode::Triangles,          /* TriangleFan */
+            gsMode == PrimitiveMode::LinesAdjacency,     /* LinesAdjacency */
+            gsMode == PrimitiveMode::LinesAdjacency,     /* LineStripAdjacency */
+            gsMode == PrimitiveMode::TrianglesAdjacency, /* TrianglesAdjacency */
+            gsMode == PrimitiveMode::TrianglesAdjacency, /* TriangleStripAdjacency */
+            false,                                       /* InvalidEnum */
+        }};
+    }
+}
 }  // namespace gl

src/libANGLE/Context.h

@@ -137,6 +137,13 @@ class StateCache final : angle::NonCopyable
         return getBasicDrawStatesErrorImpl(context);
     }
 
+    // Places that can trigger updateValidDrawModes:
+    // 1. onProgramExecutableChange.
+    bool isValidDrawMode(PrimitiveMode primitiveMode) const
+    {
+        return mCachedValidDrawModes[primitiveMode];
+    }
+
     // State change notifications.
     void onVertexArrayBindingChange(Context *context);
     void onProgramExecutableChange(Context *context);
@@ -160,6 +167,7 @@ class StateCache final : angle::NonCopyable
     void updateActiveAttribsMask(Context *context);
     void updateVertexElementLimits(Context *context);
     void updateBasicDrawStatesError();
+    void updateValidDrawModes(Context *context);
 
     intptr_t getBasicDrawStatesErrorImpl(Context *context) const;
 
@@ -172,6 +180,10 @@ class StateCache final : angle::NonCopyable
     GLint64 mCachedNonInstancedVertexElementLimit;
     GLint64 mCachedInstancedVertexElementLimit;
     mutable intptr_t mCachedBasicDrawStatesError;
+
+    // Reserve an extra slot at the end of the map for invalid enum.
+    angle::PackedEnumMap<PrimitiveMode, bool, angle::EnumSize<PrimitiveMode>() + 1>
+        mCachedValidDrawModes;
 };
 
 class Context final : public egl::LabeledObject, angle::NonCopyable, public angle::ObserverInterface