xref: /third_party/skia/src/gpu/geometry/GrRect.h (revision cb93a386)
1/*
2 * Copyright 2010 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef GrRect_DEFINED
9#define GrRect_DEFINED
10
11#include "include/core/SkMatrix.h"
12#include "include/core/SkRect.h"
13#include "include/core/SkTypes.h"
14#include "include/private/SkTo.h"
15
16struct GrIRect16 {
17    int16_t fLeft, fTop, fRight, fBottom;
18
19    static GrIRect16 SK_WARN_UNUSED_RESULT MakeEmpty() {
20        GrIRect16 r;
21        r.setEmpty();
22        return r;
23    }
24
25    static GrIRect16 SK_WARN_UNUSED_RESULT MakeWH(int16_t w, int16_t h) {
26        GrIRect16 r;
27        r.set(0, 0, w, h);
28        return r;
29    }
30
31    static GrIRect16 SK_WARN_UNUSED_RESULT MakeXYWH(int16_t x, int16_t y, int16_t w, int16_t h) {
32        GrIRect16 r;
33        r.set(x, y, x + w, y + h);
34        return r;
35    }
36
37    static GrIRect16 SK_WARN_UNUSED_RESULT Make(const SkIRect& ir) {
38        GrIRect16 r;
39        r.set(ir);
40        return r;
41    }
42
43    int width() const { return fRight - fLeft; }
44    int height() const { return fBottom - fTop; }
45    int area() const { return this->width() * this->height(); }
46    bool isEmpty() const { return fLeft >= fRight || fTop >= fBottom; }
47
48    void setEmpty() { memset(this, 0, sizeof(*this)); }
49
50    void set(int16_t left, int16_t top, int16_t right, int16_t bottom) {
51        fLeft = left;
52        fTop = top;
53        fRight = right;
54        fBottom = bottom;
55    }
56
57    void set(const SkIRect& r) {
58        fLeft   = SkToS16(r.fLeft);
59        fTop    = SkToS16(r.fTop);
60        fRight  = SkToS16(r.fRight);
61        fBottom = SkToS16(r.fBottom);
62    }
63
64    void offset(int16_t dx, int16_t dy) {
65        fLeft   += dx;
66        fTop    += dy;
67        fRight  += dx;
68        fBottom += dy;
69    }
70};
71
72/** Returns true if the rectangles have a nonzero area of overlap. It assumed that rects can be
73    infinitely small but not "inverted". */
74static inline bool GrRectsOverlap(const SkRect& a, const SkRect& b) {
75    // See skbug.com/6607 about the isFinite() checks.
76    SkASSERT(!a.isFinite() || (a.fLeft <= a.fRight && a.fTop <= a.fBottom));
77    SkASSERT(!b.isFinite() || (b.fLeft <= b.fRight && b.fTop <= b.fBottom));
78    return a.fRight > b.fLeft && a.fBottom > b.fTop && b.fRight > a.fLeft && b.fBottom > a.fTop;
79}
80
81/** Returns true if the rectangles overlap or share an edge or corner. It assumed that rects can be
82    infinitely small but not "inverted". */
83static inline bool GrRectsTouchOrOverlap(const SkRect& a, const SkRect& b) {
84    // See skbug.com/6607 about the isFinite() checks.
85    SkASSERT(!a.isFinite() || (a.fLeft <= a.fRight && a.fTop <= a.fBottom));
86    SkASSERT(!b.isFinite() || (b.fLeft <= b.fRight && b.fTop <= b.fBottom));
87    return a.fRight >= b.fLeft && a.fBottom >= b.fTop && b.fRight >= a.fLeft && b.fBottom >= a.fTop;
88}
89
90/**
91 * Apply the transform from 'inRect' to 'outRect' to each point in 'inPts', storing the mapped point
92 * into the parallel index of 'outPts'.
93 */
94static inline void GrMapRectPoints(const SkRect& inRect, const SkRect& outRect,
95                                   const SkPoint inPts[], SkPoint outPts[], int ptCount) {
96    SkMatrix::RectToRect(inRect, outRect).mapPoints(outPts, inPts, ptCount);
97}
98
99/**
100 * Clips the srcRect and the dstPoint to the bounds of the srcSize and dstSize respectively. Returns
101 * true if the srcRect and dstRect intersect the srcRect and dst rect (dstPoint with srcRect
102 * width/height). Returns false otherwise. The clipped values are returned in clippedSrcRect and
103 * clippedDstPoint.
104 */
105static inline bool GrClipSrcRectAndDstPoint(const SkISize& dstSize,
106                                            const SkISize& srcSize,
107                                            const SkIRect& srcRect,
108                                            const SkIPoint& dstPoint,
109                                            SkIRect* clippedSrcRect,
110                                            SkIPoint* clippedDstPoint) {
111    *clippedSrcRect = srcRect;
112    *clippedDstPoint = dstPoint;
113
114    // clip the left edge to src and dst bounds, adjusting dstPoint if necessary
115    if (clippedSrcRect->fLeft < 0) {
116        clippedDstPoint->fX -= clippedSrcRect->fLeft;
117        clippedSrcRect->fLeft = 0;
118    }
119    if (clippedDstPoint->fX < 0) {
120        clippedSrcRect->fLeft -= clippedDstPoint->fX;
121        clippedDstPoint->fX = 0;
122    }
123
124    // clip the top edge to src and dst bounds, adjusting dstPoint if necessary
125    if (clippedSrcRect->fTop < 0) {
126        clippedDstPoint->fY -= clippedSrcRect->fTop;
127        clippedSrcRect->fTop = 0;
128    }
129    if (clippedDstPoint->fY < 0) {
130        clippedSrcRect->fTop -= clippedDstPoint->fY;
131        clippedDstPoint->fY = 0;
132    }
133
134    // clip the right edge to the src and dst bounds.
135    if (clippedSrcRect->fRight > srcSize.width()) {
136        clippedSrcRect->fRight = srcSize.width();
137    }
138    if (clippedDstPoint->fX + clippedSrcRect->width() > dstSize.width()) {
139        clippedSrcRect->fRight = clippedSrcRect->fLeft + dstSize.width() - clippedDstPoint->fX;
140    }
141
142    // clip the bottom edge to the src and dst bounds.
143    if (clippedSrcRect->fBottom > srcSize.height()) {
144        clippedSrcRect->fBottom = srcSize.height();
145    }
146    if (clippedDstPoint->fY + clippedSrcRect->height() > dstSize.height()) {
147        clippedSrcRect->fBottom = clippedSrcRect->fTop + dstSize.height() - clippedDstPoint->fY;
148    }
149
150    // The above clipping steps may have inverted the rect if it didn't intersect either the src or
151    // dst bounds.
152    return !clippedSrcRect->isEmpty();
153}
154#endif
155