kc3-lang/angle

2016-12-19T14:19:10

ES31: Implement DrawArraysIndirect D3D part There are four buffer types for vertex attribute storage in D3D11: DIRECT STATIC DYNAMIC CURRENT_VALUE When drawing, it will call applyVertexBuffer to bind the right type buffers in D3D11. DIRECT uses the gl buffer directly without any translation. CURRENT_VALUE uses a single value for the attribute. STATIC translates the whole vertex buffer once. So it doesn't need the first, count and instance informations since it always translates the whole buffer. DYNAMIC translates the data every frame. To improve the performance, in implementation, it only translates 'count' vertexes from 'first' location in vertex buffer with one drawing for non-instanced vertices. 'first' and 'count' are got from draw parameter list. And for the translated vertex buffer, when drawing, the first vertex location is 0. From above analysis, we can see that if all attribute storages are non-dynamic, we can directly use the indirect buffer to draw. But for dynamic storages, we have to calculate the first, count, and instances from indirect buffer and apply them to translate the dynamic type buffers. Meanwhile, we have to set the first to 0 (see above description)when drawing. DrawArrysIndirect implementation is like below: 1. Check whether all vertex attributes are non-dynamic 2. If yes, applyVertexBuffer and DrawInstancedIndirect 3. If no, 1) calculate first, count, and instances from indirect buffer. 2) applyVertexBuffer with these parameters. 4) Use DrawInstanced instead of DrawInstancedIndirect. BUG=angleproject:1595 TEST=dEQP-GLES31.functional.draw_indirect.draw_arrays_indirect* Change-Id: I36431f416443279d51de523b07ce60727914cbbf Reviewed-on: https://chromium-review.googlesource.com/446690 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>