libs/hwui/PathTessellator.h

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ANDROID_HWUI_PATH_TESSELLATOR_H
#define ANDROID_HWUI_PATH_TESSELLATOR_H

#include <utils/Vector.h>

#include "Matrix.h"
#include "Rect.h"
#include "Vertex.h"
#include "VertexBuffer.h"

namespace android {
namespace uirenderer {

class PathTessellator {
public:
    static void expandBoundsForStroke(SkRect& bounds, const SkPaint* paint);

    static void tessellatePath(const SkPath& path, const SkPaint* paint,
            const mat4& transform, VertexBuffer& vertexBuffer);

    static void tessellatePoints(const float* points, int count, const SkPaint* paint,
            const mat4& transform, SkRect& bounds, VertexBuffer& vertexBuffer);

    static void tessellateLines(const float* points, int count, const SkPaint* paint,
            const mat4& transform, SkRect& bounds, VertexBuffer& vertexBuffer);

private:
    static bool approximatePathOutlineVertices(const SkPath &path, bool forceClose,
        float sqrInvScaleX, float sqrInvScaleY, Vector<Vertex> &outputVertices);

/*
  endpoints a & b,
  control c
 */
    static void recursiveQuadraticBezierVertices(
            float ax, float ay,
            float bx, float by,
            float cx, float cy,
            float sqrInvScaleX, float sqrInvScaleY,
            Vector<Vertex> &outputVertices);

/*
  endpoints p1, p2
  control c1, c2
 */
    static void recursiveCubicBezierVertices(
            float p1x, float p1y,
            float c1x, float c1y,
            float p2x, float p2y,
            float c2x, float c2y,
            float sqrInvScaleX, float sqrInvScaleY,
            Vector<Vertex> &outputVertices);
};

}; // namespace uirenderer
}; // namespace android

#endif // ANDROID_HWUI_PATH_TESSELLATOR_H