SpotShadow.h revision f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_HWUI_SPOT_SHADOW_H
18#define ANDROID_HWUI_SPOT_SHADOW_H
19
20#include "Debug.h"
21#include "Vector.h"
22#include "VertexBuffer.h"
23
24namespace android {
25namespace uirenderer {
26
27class SpotShadow {
28public:
29    static void createSpotShadow(const Vector3* poly, int polyLength,
30            const Vector3& lightCenter, float lightSize, int lightVertexCount,
31            int rays, int layers, float strength, VertexBuffer& retStrips);
32
33private:
34    static void computeSpotShadow(const Vector3* lightPoly, int lightPolyLength,
35            const Vector3& lightCenter, const Vector3* poly, int polyLength,
36            int rays, int layers, float strength, VertexBuffer& retstrips);
37
38    static void computeLightPolygon(int points, const Vector3& lightCenter,
39            float size, Vector3* ret);
40
41    static int  getStripSize(int rays, int layers);
42    static void smoothPolygon(int level, int rays, float* rayDist);
43    static float calculateOpacity(float jf, float deltaDist);
44    static float rayIntersectPoly(const Vector2* poly, int polyLength,
45            const Vector2& point, float dx, float dy);
46
47    static Vector2 centroid2d(const Vector2* poly, int polyLength);
48
49    static void xsort(Vector2* points, int pointsLength);
50    static int hull(Vector2* points, int pointsLength, Vector2* retPoly);
51    static bool ccw(double ax, double ay, double bx, double by, double cx, double cy);
52    static int intersection(Vector2* poly1, int poly1length, Vector2* poly2, int poly2length);
53    static void sort(Vector2* poly, int polyLength, const Vector2& center);
54
55    static float angle(const Vector2& point, const Vector2& center);
56    static void swap(Vector2* points, int i, int j);
57    static void quicksortCirc(Vector2* points, int low, int high, const Vector2& center);
58    static void quicksortX(Vector2* points, int low, int high);
59
60    static bool testPointInsidePolygon(const Vector2 testPoint, const Vector2* poly, int len);
61    static void makeClockwise(Vector2* polygon, int len);
62    static bool isClockwise(Vector2* polygon, int len);
63    static void reverse(Vector2* polygon, int len);
64    static inline bool lineIntersection(double x1, double y1, double x2, double y2,
65            double x3, double y3, double x4, double y4, Vector2& ret);
66
67    static void generateTriangleStrip(const Vector2* penumbra, int penumbraLength,
68            const Vector2* umbra, int umbraLength, int rays, int layers,
69            float strength, VertexBuffer& retstrips);
70
71    static const double EPSILON = 1e-7;
72
73#if DEBUG_SHADOW
74    // Verification utility function.
75    static bool testConvex(const Vector2* polygon, int polygonLength,
76            const char* name);
77    static void testIntersection(const Vector2* poly1, int poly1Length,
78        const Vector2* poly2, int poly2Length,
79        const Vector2* intersection, int intersectionLength);
80    static void updateBound(const Vector2 inVector, Vector2& lowerBound, Vector2& upperBound );
81#endif
82
83}; // SpotShadow
84
85}; // namespace uirenderer
86}; // namespace android
87
88#endif // ANDROID_HWUI_SPOT_SHADOW_H
89