1 /*
2  * Copyright (C) 2015 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 #include "Canvas.h"
18 
19 #include "MinikinUtils.h"
20 #include "Paint.h"
21 #include "Properties.h"
22 #include "RenderNode.h"
23 #include "Typeface.h"
24 #include "pipeline/skia/SkiaRecordingCanvas.h"
25 
26 #include "hwui/PaintFilter.h"
27 
28 #include <SkFontMetrics.h>
29 
30 namespace android {
31 
create_recording_canvas(int width,int height,uirenderer::RenderNode * renderNode)32 Canvas* Canvas::create_recording_canvas(int width, int height, uirenderer::RenderNode* renderNode) {
33     return new uirenderer::skiapipeline::SkiaRecordingCanvas(renderNode, width, height);
34 }
35 
drawStroke(SkScalar left,SkScalar right,SkScalar top,SkScalar thickness,const Paint & paint,Canvas * canvas)36 static inline void drawStroke(SkScalar left, SkScalar right, SkScalar top, SkScalar thickness,
37                               const Paint& paint, Canvas* canvas) {
38     const SkScalar strokeWidth = fmax(thickness, 1.0f);
39     const SkScalar bottom = top + strokeWidth;
40     canvas->drawRect(left, top, right, bottom, paint);
41 }
42 
drawTextDecorations(float x,float y,float length,const Paint & paint)43 void Canvas::drawTextDecorations(float x, float y, float length, const Paint& paint) {
44     // paint has already been filtered by our caller, so we can ignore any filter
45     const bool strikeThru = paint.isStrikeThru();
46     const bool underline = paint.isUnderline();
47     if (strikeThru || underline) {
48         const SkScalar left = x;
49         const SkScalar right = x + length;
50         const float textSize = paint.getSkFont().getSize();
51         if (underline) {
52             SkFontMetrics metrics;
53             paint.getSkFont().getMetrics(&metrics);
54             SkScalar position;
55             if (!metrics.hasUnderlinePosition(&position)) {
56                 position = textSize * Paint::kStdUnderline_Top;
57             }
58             SkScalar thickness;
59             if (!metrics.hasUnderlineThickness(&thickness)) {
60                 thickness = textSize * Paint::kStdUnderline_Thickness;
61             }
62             const SkScalar top = y + position;
63             drawStroke(left, right, top, thickness, paint, this);
64         }
65         if (strikeThru) {
66             const float position = textSize * Paint::kStdStrikeThru_Top;
67             const SkScalar thickness = textSize * Paint::kStdStrikeThru_Thickness;
68             const SkScalar top = y + position;
69             drawStroke(left, right, top, thickness, paint, this);
70         }
71     }
72 }
73 
simplifyPaint(int color,Paint * paint)74 static void simplifyPaint(int color, Paint* paint) {
75     paint->setColor(color);
76     paint->setShader(nullptr);
77     paint->setColorFilter(nullptr);
78     paint->setLooper(nullptr);
79     paint->setStrokeWidth(4 + 0.04 * paint->getSkFont().getSize());
80     paint->setStrokeJoin(SkPaint::kRound_Join);
81     paint->setLooper(nullptr);
82 }
83 
84 class DrawTextFunctor {
85 public:
DrawTextFunctor(const minikin::Layout & layout,Canvas * canvas,const Paint & paint,float x,float y,minikin::MinikinRect & bounds,float totalAdvance)86     DrawTextFunctor(const minikin::Layout& layout, Canvas* canvas, const Paint& paint, float x,
87                     float y, minikin::MinikinRect& bounds, float totalAdvance)
88             : layout(layout)
89             , canvas(canvas)
90             , paint(paint)
91             , x(x)
92             , y(y)
93             , bounds(bounds)
94             , totalAdvance(totalAdvance) {}
95 
operator ()(size_t start,size_t end)96     void operator()(size_t start, size_t end) {
97         auto glyphFunc = [&](uint16_t* text, float* positions) {
98             for (size_t i = start, textIndex = 0, posIndex = 0; i < end; i++) {
99                 text[textIndex++] = layout.getGlyphId(i);
100                 positions[posIndex++] = x + layout.getX(i);
101                 positions[posIndex++] = y + layout.getY(i);
102             }
103         };
104 
105         size_t glyphCount = end - start;
106 
107         if (CC_UNLIKELY(canvas->isHighContrastText() && paint.getAlpha() != 0)) {
108             // high contrast draw path
109             int color = paint.getColor();
110             int channelSum = SkColorGetR(color) + SkColorGetG(color) + SkColorGetB(color);
111             bool darken = channelSum < (128 * 3);
112 
113             // outline
114             Paint outlinePaint(paint);
115             simplifyPaint(darken ? SK_ColorWHITE : SK_ColorBLACK, &outlinePaint);
116             outlinePaint.setStyle(SkPaint::kStrokeAndFill_Style);
117             canvas->drawGlyphs(glyphFunc, glyphCount, outlinePaint, x, y, bounds.mLeft, bounds.mTop,
118                                bounds.mRight, bounds.mBottom, totalAdvance);
119 
120             // inner
121             Paint innerPaint(paint);
122             simplifyPaint(darken ? SK_ColorBLACK : SK_ColorWHITE, &innerPaint);
123             innerPaint.setStyle(SkPaint::kFill_Style);
124             canvas->drawGlyphs(glyphFunc, glyphCount, innerPaint, x, y, bounds.mLeft, bounds.mTop,
125                                bounds.mRight, bounds.mBottom, totalAdvance);
126         } else {
127             // standard draw path
128             canvas->drawGlyphs(glyphFunc, glyphCount, paint, x, y, bounds.mLeft, bounds.mTop,
129                                bounds.mRight, bounds.mBottom, totalAdvance);
130         }
131     }
132 
133 private:
134     const minikin::Layout& layout;
135     Canvas* canvas;
136     const Paint& paint;
137     float x;
138     float y;
139     minikin::MinikinRect& bounds;
140     float totalAdvance;
141 };
142 
drawText(const uint16_t * text,int textSize,int start,int count,int contextStart,int contextCount,float x,float y,minikin::Bidi bidiFlags,const Paint & origPaint,const Typeface * typeface,minikin::MeasuredText * mt)143 void Canvas::drawText(const uint16_t* text, int textSize, int start, int count, int contextStart,
144                       int contextCount, float x, float y, minikin::Bidi bidiFlags,
145                       const Paint& origPaint, const Typeface* typeface, minikin::MeasuredText* mt) {
146     // minikin may modify the original paint
147     Paint paint(origPaint);
148 
149     // interpret 'linear metrics' flag as 'linear', forcing no-hinting when drawing
150     if (paint.getSkFont().isLinearMetrics()) {
151         paint.getSkFont().setHinting(SkFontHinting::kNone);
152     }
153 
154     minikin::Layout layout = MinikinUtils::doLayout(&paint, bidiFlags, typeface, text, textSize,
155                                                     start, count, contextStart, contextCount, mt);
156 
157     x += MinikinUtils::xOffsetForTextAlign(&paint, layout);
158 
159     minikin::MinikinRect bounds;
160     layout.getBounds(&bounds);
161 
162     // Set align to left for drawing, as we don't want individual
163     // glyphs centered or right-aligned; the offset above takes
164     // care of all alignment.
165     paint.setTextAlign(Paint::kLeft_Align);
166 
167     DrawTextFunctor f(layout, this, paint, x, y, bounds, layout.getAdvance());
168     MinikinUtils::forFontRun(layout, &paint, f);
169 }
170 
drawDoubleRoundRectXY(float outerLeft,float outerTop,float outerRight,float outerBottom,float outerRx,float outerRy,float innerLeft,float innerTop,float innerRight,float innerBottom,float innerRx,float innerRy,const Paint & paint)171 void Canvas::drawDoubleRoundRectXY(float outerLeft, float outerTop, float outerRight,
172                             float outerBottom, float outerRx, float outerRy, float innerLeft,
173                             float innerTop, float innerRight, float innerBottom, float innerRx,
174                             float innerRy, const Paint& paint) {
175     if (CC_UNLIKELY(paint.nothingToDraw())) return;
176     SkRect outer = SkRect::MakeLTRB(outerLeft, outerTop, outerRight, outerBottom);
177     SkRect inner = SkRect::MakeLTRB(innerLeft, innerTop, innerRight, innerBottom);
178 
179     SkRRect outerRRect;
180     outerRRect.setRectXY(outer, outerRx, outerRy);
181 
182     SkRRect innerRRect;
183     innerRRect.setRectXY(inner, innerRx, innerRy);
184     drawDoubleRoundRect(outerRRect, innerRRect, paint);
185 }
186 
drawDoubleRoundRectRadii(float outerLeft,float outerTop,float outerRight,float outerBottom,const float * outerRadii,float innerLeft,float innerTop,float innerRight,float innerBottom,const float * innerRadii,const Paint & paint)187 void Canvas::drawDoubleRoundRectRadii(float outerLeft, float outerTop, float outerRight,
188                             float outerBottom, const float* outerRadii, float innerLeft,
189                             float innerTop, float innerRight, float innerBottom,
190                             const float* innerRadii, const Paint& paint) {
191     static_assert(sizeof(SkVector) == sizeof(float) * 2);
192     if (CC_UNLIKELY(paint.nothingToDraw())) return;
193     SkRect outer = SkRect::MakeLTRB(outerLeft, outerTop, outerRight, outerBottom);
194     SkRect inner = SkRect::MakeLTRB(innerLeft, innerTop, innerRight, innerBottom);
195 
196     SkRRect outerRRect;
197     const SkVector* outerSkVector = reinterpret_cast<const SkVector*>(outerRadii);
198     outerRRect.setRectRadii(outer, outerSkVector);
199 
200     SkRRect innerRRect;
201     const SkVector* innerSkVector = reinterpret_cast<const SkVector*>(innerRadii);
202     innerRRect.setRectRadii(inner, innerSkVector);
203     drawDoubleRoundRect(outerRRect, innerRRect, paint);
204 }
205 
206 class DrawTextOnPathFunctor {
207 public:
DrawTextOnPathFunctor(const minikin::Layout & layout,Canvas * canvas,float hOffset,float vOffset,const Paint & paint,const SkPath & path)208     DrawTextOnPathFunctor(const minikin::Layout& layout, Canvas* canvas, float hOffset,
209                           float vOffset, const Paint& paint, const SkPath& path)
210             : layout(layout)
211             , canvas(canvas)
212             , hOffset(hOffset)
213             , vOffset(vOffset)
214             , paint(paint)
215             , path(path) {}
216 
operator ()(size_t start,size_t end)217     void operator()(size_t start, size_t end) {
218         canvas->drawLayoutOnPath(layout, hOffset, vOffset, paint, path, start, end);
219     }
220 
221 private:
222     const minikin::Layout& layout;
223     Canvas* canvas;
224     float hOffset;
225     float vOffset;
226     const Paint& paint;
227     const SkPath& path;
228 };
229 
drawTextOnPath(const uint16_t * text,int count,minikin::Bidi bidiFlags,const SkPath & path,float hOffset,float vOffset,const Paint & origPaint,const Typeface * typeface)230 void Canvas::drawTextOnPath(const uint16_t* text, int count, minikin::Bidi bidiFlags,
231                             const SkPath& path, float hOffset, float vOffset,
232                             const Paint& origPaint, const Typeface* typeface) {
233     // minikin may modify the original paint
234     Paint paint(origPaint);
235 
236     // interpret 'linear metrics' flag as 'linear', forcing no-hinting when drawing
237     if (paint.getSkFont().isLinearMetrics()) {
238         paint.getSkFont().setHinting(SkFontHinting::kNone);
239     }
240 
241     minikin::Layout layout =
242             MinikinUtils::doLayout(&paint, bidiFlags, typeface, text, count,  // text buffer
243                                    0, count,                                  // draw range
244                                    0, count,                                  // context range
245                                    nullptr);
246     hOffset += MinikinUtils::hOffsetForTextAlign(&paint, layout, path);
247 
248     // Set align to left for drawing, as we don't want individual
249     // glyphs centered or right-aligned; the offset above takes
250     // care of all alignment.
251     paint.setTextAlign(Paint::kLeft_Align);
252 
253     DrawTextOnPathFunctor f(layout, this, hOffset, vOffset, paint, path);
254     MinikinUtils::forFontRun(layout, &paint, f);
255 }
256 
257 int Canvas::sApiLevel = 1;
258 
setCompatibilityVersion(int apiLevel)259 void Canvas::setCompatibilityVersion(int apiLevel) {
260     sApiLevel = apiLevel;
261 }
262 
263 }  // namespace android
264