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 
24 namespace android {
25 namespace uirenderer {
26 
27 class SpotShadow {
28 public:
29     static void createSpotShadow(bool isCasterOpaque, const Vector3& lightCenter,
30             float lightSize, const Vector3* poly, int polyLength,
31             const Vector3& polyCentroid, VertexBuffer& retstrips);
32 
33 private:
34     struct VertexAngleData;
35 
36     static float projectCasterToOutline(Vector2& outline,
37             const Vector3& lightCenter, const Vector3& polyVertex);
38 
39     static void computeLightPolygon(int points, const Vector3& lightCenter,
40             float size, Vector3* ret);
41 
42     static void smoothPolygon(int level, int rays, float* rayDist);
43     static float rayIntersectPoly(const Vector2* poly, int polyLength,
44             const Vector2& point, float dx, float dy);
45 
46     static void xsort(Vector2* points, int pointsLength);
47     static int hull(Vector2* points, int pointsLength, Vector2* retPoly);
48     static bool ccw(float ax, float ay, float bx, float by, float cx, float cy);
49     static void sort(Vector2* poly, int polyLength, const Vector2& center);
50 
51     static void swap(Vector2* points, int i, int j);
52     static void quicksortCirc(Vector2* points, int low, int high, const Vector2& center);
53     static void quicksortX(Vector2* points, int low, int high);
54 
55     static bool testPointInsidePolygon(const Vector2 testPoint, const Vector2* poly, int len);
56     static void makeClockwise(Vector2* polygon, int len);
57     static void reverse(Vector2* polygon, int len);
58 
59     static void generateTriangleStrip(bool isCasterOpaque, float shadowStrengthScale,
60             Vector2* penumbra, int penumbraLength, Vector2* umbra, int umbraLength,
61             const Vector3* poly, int polyLength, VertexBuffer& retstrips, const Vector2& centroid);
62 
63 #if DEBUG_SHADOW
64     static bool testConvex(const Vector2* polygon, int polygonLength,
65             const char* name);
66     static void testIntersection(const Vector2* poly1, int poly1Length,
67         const Vector2* poly2, int poly2Length,
68         const Vector2* intersection, int intersectionLength);
69     static void updateBound(const Vector2 inVector, Vector2& lowerBound, Vector2& upperBound );
70     static void dumpPolygon(const Vector2* poly, int polyLength, const char* polyName);
71     static void dumpPolygon(const Vector3* poly, int polyLength, const char* polyName);
72 #endif
73 
74 }; // SpotShadow
75 
76 }; // namespace uirenderer
77 }; // namespace android
78 
79 #endif // ANDROID_HWUI_SPOT_SHADOW_H
80