[ganesh] Apply buffer binding restriction

WebGL has buffer binding restriction that mixing index buffer and other data is
invalid.

src/gpu/ganesh/gl/GrGLBuffer.cpp

@@ -100,6 +100,37 @@ inline static GrGLenum gr_to_gl_access_pattern(GrGpuBufferType bufferType,
     return usageType(bufferType, accessPattern);
 }
 
+#ifdef SK_DEBUG
+bool GrGLBuffer::validBindingTarget(GrGLenum target) const {
+    if (!this->glCaps().bufferBindingRestriction()) {
+        return true;
+    }
+    /* This restriction implies that a given buffer object may contain
+     * either indices or other data, but not both.
+     */
+    if (GR_GL_ELEMENT_ARRAY_BUFFER == target) {
+        switch (this->fBindingCategory) {
+            case kUndefined_BindingCategory:
+                this->fBindingCategory = kIndexBuffer_BindingCategory;
+                [[fallthrough]];
+            case kIndexBuffer_BindingCategory:
+                return true;
+            default:
+                return false;
+        }
+    }
+    switch (this->fBindingCategory) {
+        case kUndefined_BindingCategory:
+            this->fBindingCategory = kOtherData_BindingCategory;
+            [[fallthrough]];
+        case kOtherData_BindingCategory:
+            return true;
+        default:
+            return false;
+    }
+}
+#endif // SK_DEBUG
+
 GrGLBuffer::GrGLBuffer(GrGLGpu* gpu,
                        size_t size,
                        GrGpuBufferType intendedType,

src/gpu/ganesh/gl/GrGLBuffer.h

@@ -31,6 +31,10 @@ class GrGLBuffer : public GrGpuBuffer {
     void setHasAttachedToTexture() { fHasAttachedToTexture = true; }
     bool hasAttachedToTexture() const { return fHasAttachedToTexture; }
 
+#ifdef SK_DEBUG
+    bool validBindingTarget(GrGLenum target) const;
+#endif // SK_DEBUG
+
 protected:
     GrGLBuffer(GrGLGpu*,
                size_t size,
@@ -59,6 +63,15 @@ class GrGLBuffer : public GrGpuBuffer {
     GrGLenum        fUsage;
     bool            fHasAttachedToTexture;
 
+#ifdef SK_DEBUG
+    enum BindingCategory {
+      kUndefined_BindingCategory,
+      kIndexBuffer_BindingCategory,
+      kOtherData_BindingCategory,
+    };
+    mutable BindingCategory fBindingCategory;
+#endif // SK_DEBUG
+
     using INHERITED = GrGpuBuffer;
 };
 

src/gpu/ganesh/gl/GrGLCaps.cpp

@@ -261,6 +261,12 @@ void GrGLCaps::init(const GrContextOptions& contextOptions,
         fClientCanDisableMultisample = false;
     }
 
+    if (GR_IS_GR_GL(standard) || GR_IS_GR_GL_ES(standard)) {
+        fBufferBindingRestriction = false;
+    } else if (GR_IS_GR_WEBGL(standard)) {
+        fBufferBindingRestriction = true;
+    }
+
     if (GR_IS_GR_GL(standard)) {
         // 3.1 has draw_instanced but not instanced_arrays, for the time being we only care about
         // instanced arrays, but we could make this more granular if we wanted

src/gpu/ganesh/gl/GrGLCaps.h

@@ -515,6 +515,9 @@ class GrGLCaps : public GrCaps {
 
     bool clientCanDisableMultisample() const { return fClientCanDisableMultisample; }
 
+    /* https://registry.khronos.org/webgl/specs/latest/2.0/#BUFFER_OBJECT_BINDING */
+    bool bufferBindingRestriction() const { return fBufferBindingRestriction; }
+
     GrBackendFormat getBackendFormatFromCompressionType(SkTextureCompressionType) const override;
 
     skgpu::Swizzle getWriteSwizzle(const GrBackendFormat&, GrColorType) const override;
@@ -630,6 +633,7 @@ class GrGLCaps : public GrCaps {
     bool fSRGBWriteControl : 1;
     bool fSkipErrorChecks : 1;
     bool fClientCanDisableMultisample : 1;
+    bool fBufferBindingRestriction: 1;
 
     // Driver workarounds
     bool fDoManualMipmapping : 1;

src/gpu/ganesh/gl/GrGLGpu.cpp

@@ -2158,6 +2158,7 @@ GrGLenum GrGLGpu::bindBuffer(GrGpuBufferType type, const GrBuffer* buffer) {
     } else if (static_cast<const GrGpuBuffer*>(buffer)->uniqueID() !=
                bufferState->fBoundBufferUniqueID) {
         const GrGLBuffer* glBuffer = static_cast<const GrGLBuffer*>(buffer);
+        SkASSERT(glBuffer->validBindingTarget(bufferState->fGLTarget));
         GL_CALL(BindBuffer(bufferState->fGLTarget, glBuffer->bufferID()));
         bufferState->fBufferZeroKnownBound = false;
         bufferState->fBoundBufferUniqueID = glBuffer->uniqueID();