From b0a9477c8e07d4530f07c78a5d20b4cde0fe8d60 Mon Sep 17 00:00:00 2001 From: Arun Date: Mon, 23 Jan 2017 11:41:06 +0000 Subject: [PATCH] Reduce hwui CPU time by using glDrawRangeElements The CPU overhead of glDrawElements in the GPU driver is significant with client-side vertex data (unique per draw call) as the driver has to calculate the mininimum and maximum indices from the index buffer in order to evaluate the range of vertex data required. This can be avoided by keeping track of the min-max in hwui and passing it with glDrawRangeElements. This requires OpenGL ES3.0 support (which is already checked for elsewhere in hwui). Test: manual - visual inspection on fugu (nexus player) Change-Id: I57bb1ddd239a1032f74f1cd2683bbe0970e84bd9 --- libs/hwui/Glop.h | 1 + libs/hwui/GlopBuilder.cpp | 1 + libs/hwui/renderstate/RenderState.cpp | 16 +++++++++++++--- 3 files changed, 15 insertions(+), 3 deletions(-) diff --git a/libs/hwui/Glop.h b/libs/hwui/Glop.h index 6433c86908e7a..b95fd6311636e 100644 --- a/libs/hwui/Glop.h +++ b/libs/hwui/Glop.h @@ -112,6 +112,7 @@ public: } vertices; int elementCount; + int vertexCount; // only used for meshes (for glDrawRangeElements) TextureVertex mappedVertices[4]; } mesh; diff --git a/libs/hwui/GlopBuilder.cpp b/libs/hwui/GlopBuilder.cpp index e502725ddb099..8fcd1ea1f9fca 100644 --- a/libs/hwui/GlopBuilder.cpp +++ b/libs/hwui/GlopBuilder.cpp @@ -210,6 +210,7 @@ GlopBuilder& GlopBuilder::setMeshVertexBuffer(const VertexBuffer& vertexBuffer) alphaVertex ? kAlphaVertexStride : kVertexStride }; mOutGlop->mesh.elementCount = indices ? vertexBuffer.getIndexCount() : vertexBuffer.getVertexCount(); + mOutGlop->mesh.vertexCount = vertexBuffer.getVertexCount(); // used for glDrawRangeElements() return *this; } diff --git a/libs/hwui/renderstate/RenderState.cpp b/libs/hwui/renderstate/RenderState.cpp index 5e600644ca193..c4e8e4f2df6e7 100644 --- a/libs/hwui/renderstate/RenderState.cpp +++ b/libs/hwui/renderstate/RenderState.cpp @@ -364,18 +364,28 @@ void RenderState::render(const Glop& glop, const Matrix4& orthoMatrix) { const GLbyte* vertexData = static_cast(vertices.position); while (elementsCount > 0) { GLsizei drawCount = std::min(elementsCount, (GLsizei) kMaxNumberOfQuads * 6); + GLsizei vertexCount = (drawCount / 6) * 4; meshState().bindPositionVertexPointer(vertexData, vertices.stride); if (vertices.attribFlags & VertexAttribFlags::TextureCoord) { meshState().bindTexCoordsVertexPointer( vertexData + kMeshTextureOffset, vertices.stride); } - glDrawElements(mesh.primitiveMode, drawCount, GL_UNSIGNED_SHORT, nullptr); + if (mCaches->extensions().getMajorGlVersion() >= 3) { + glDrawRangeElements(mesh.primitiveMode, 0, vertexCount-1, drawCount, GL_UNSIGNED_SHORT, nullptr); + } else { + glDrawElements(mesh.primitiveMode, drawCount, GL_UNSIGNED_SHORT, nullptr); + } elementsCount -= drawCount; - vertexData += (drawCount / 6) * 4 * vertices.stride; + vertexData += vertexCount * vertices.stride; } } else if (indices.bufferObject || indices.indices) { - glDrawElements(mesh.primitiveMode, mesh.elementCount, GL_UNSIGNED_SHORT, indices.indices); + if (mCaches->extensions().getMajorGlVersion() >= 3) { + // use glDrawRangeElements to reduce CPU overhead (otherwise the driver has to determine the min/max index values) + glDrawRangeElements(mesh.primitiveMode, 0, mesh.vertexCount-1, mesh.elementCount, GL_UNSIGNED_SHORT, indices.indices); + } else { + glDrawElements(mesh.primitiveMode, mesh.elementCount, GL_UNSIGNED_SHORT, indices.indices); + } } else { glDrawArrays(mesh.primitiveMode, 0, mesh.elementCount); }