Add default for arguments of draw and drawIndirect. (gpuweb#632)

Kangz · kainino0x · web-flow · commit 1abc267071dd · 2020-03-30T15:11:05.000-07:00
Co-authored-by: Kai Ninomiya &lt;kainino@chromium.org&gt;
diff --git a/spec/index.bs b/spec/index.bs
@@ -2575,10 +2575,12 @@ interface mixin GPURenderEncoderBase {
     void setIndexBuffer(GPUBuffer buffer, optional GPUSize64 offset = 0, optional GPUSize64 size = 0);
     void setVertexBuffer(GPUIndex32 slot, GPUBuffer buffer, optional GPUSize64 offset = 0, optional GPUSize64 size = 0);
 
-    void draw(GPUSize32 vertexCount, GPUSize32 instanceCount,
-              GPUSize32 firstVertex, GPUSize32 firstInstance);
-    void drawIndexed(GPUSize32 indexCount, GPUSize32 instanceCount,
-                     GPUSize32 firstIndex, GPUSignedOffset32 baseVertex, GPUSize32 firstInstance);
+    void draw(GPUSize32 vertexCount, optional GPUSize32 instanceCount = 1,
+              optional GPUSize32 firstVertex = 0, optional GPUSize32 firstInstance = 0);
+    void drawIndexed(GPUSize32 indexCount, optional GPUSize32 instanceCount = 1,
+                     optional GPUSize32 firstIndex = 0,
+                     optional GPUSignedOffset32 baseVertex = 0,
+                     optional GPUSize32 firstInstance = 0);
 
     void drawIndirect(GPUBuffer indirectBuffer, GPUSize64 indirectOffset);
     void drawIndexedIndirect(GPUBuffer indirectBuffer, GPUSize64 indirectOffset);
