Optimize tesselated path renderer

Two optimizations for the tesselated path renderer:

1)  If the path contains a single convex subpath, and we're not using inverted fill modes, skip the tesselation and draw the interpolated path as a triangle fan directly.
2)  Use GrDrawTarget.set*SourceToArray(), rather than creating a new AutoReleaseGeometry, saving a copy of the vertex and index data.

[bsalomon, 2011-03-29 16:14:08]

LGTM

On Tue, Mar 29, 2011 at 9:02 AM, <senorblanco@chromium.org> wrote:

> Reviewers: bsalomon, reed,
>
> Description:
> Two optimizations for the tesselated path renderer:
>
> 1)  If the path contains a single convex subpath, and we're not using
> inverted fill modes, skip the tesselation and draw the interpolated path
> as a triangle fan directly.
> 2)  Use GrDrawTarget.set*SourceToArray(), rather than creating a new
> AutoReleaseGeometry, saving a copy of the vertex and index data.
>
> Please review this at http://codereview.appspot.com/4280076/
>
> Affected files:
>  gpu/src/GrTesselatedPathRenderer.cpp
>
>
> Index: gpu/src/GrTesselatedPathRenderer.cpp
> ===================================================================
> --- gpu/src/GrTesselatedPathRenderer.cpp        (revision 1013)
> +++ gpu/src/GrTesselatedPathRenderer.cpp        (working copy)
> @@ -205,6 +205,13 @@
>
>     size_t count = vert - base;
>
> +    if (subpathCnt == 1 && !inverted && path->convexHint() ==
> kConvex_ConvexHint) {
> +        target->setVertexSourceToArray(layout, base, count);
> +        target->drawNonIndexed(kTriangleFan_PrimitiveType, 0, count);
> +        delete[] base;
> +        return;
> +    }
> +
>     // FIXME:  This copy could be removed if we had (templated?) versions
> of
>     // generate_*_point above that wrote directly into doubles.
>     double* inVertices = new double[count * 3];
> @@ -243,15 +250,9 @@
>     internal_gluTessEndPolygon(tess);
>     internal_gluDeleteTess(tess);
>
> -    // FIXME:  If we could figure out the maxIndices before running the
> -    // tesselator, we could allocate the geometry upfront, rather than
> making
> -    // yet another copy.
> -    GrDrawTarget::AutoReleaseGeometry geom(target, layout,
> vertices.count(), indices.count());
> -
> -    memcpy(geom.vertices(), vertices.begin(), vertices.count() *
> sizeof(GrPoint));
> -    memcpy(geom.indices(), indices.begin(), indices.count() *
> sizeof(short));
> -
>     if (indices.count() > 0) {
> +        target->setVertexSourceToArray(layout, vertices.begin(),
> vertices.count());
> +        target->setIndexSourceToArray(indices.begin(), indices.count());
>         target->drawIndexed(kTriangles_PrimitiveType,
>                             0,
>                             0,
>
>
>

[Stephen White, 2011-03-29 17:43:06]

Landed as http://code.google.com/p/skia/source/detail?r=1014.  Closing.