TestUtils.cpp revision d7448e65e243754f31890baef29dff187dc2e5e5 
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 "TestUtils.h"
18
19namespace android {
20namespace uirenderer {
21
22SkColor TestUtils::interpolateColor(float fraction, SkColor start, SkColor end) {
23    int startA = (start >> 24) & 0xff;
24    int startR = (start >> 16) & 0xff;
25    int startG = (start >> 8) & 0xff;
26    int startB = start & 0xff;
27
28    int endA = (end >> 24) & 0xff;
29    int endR = (end >> 16) & 0xff;
30    int endG = (end >> 8) & 0xff;
31    int endB = end & 0xff;
32
33    return (int)((startA + (int)(fraction * (endA - startA))) << 24)
34            | (int)((startR + (int)(fraction * (endR - startR))) << 16)
35            | (int)((startG + (int)(fraction * (endG - startG))) << 8)
36            | (int)((startB + (int)(fraction * (endB - startB))));
37}
38
39void TestUtils::drawTextToCanvas(TestCanvas* canvas, const char* text,
40        const SkPaint& paint, float x, float y) {
41    // drawing text requires GlyphID TextEncoding (which JNI layer would have done)
42    LOG_ALWAYS_FATAL_IF(paint.getTextEncoding() != SkPaint::kGlyphID_TextEncoding,
43            "must use glyph encoding");
44    SkSurfaceProps surfaceProps(0, kUnknown_SkPixelGeometry);
45    SkAutoGlyphCacheNoGamma autoCache(paint, &surfaceProps, &SkMatrix::I());
46
47    float totalAdvance = 0;
48    std::vector<glyph_t> glyphs;
49    std::vector<float> positions;
50    Rect bounds;
51    while (*text != '\0') {
52        SkUnichar unichar = SkUTF8_NextUnichar(&text);
53        glyph_t glyph = autoCache.getCache()->unicharToGlyph(unichar);
54        autoCache.getCache()->unicharToGlyph(unichar);
55
56        // push glyph and its relative position
57        glyphs.push_back(glyph);
58        positions.push_back(totalAdvance);
59        positions.push_back(0);
60
61        // compute bounds
62        SkGlyph skGlyph = autoCache.getCache()->getUnicharMetrics(unichar);
63        Rect glyphBounds(skGlyph.fWidth, skGlyph.fHeight);
64        glyphBounds.translate(totalAdvance + skGlyph.fLeft, skGlyph.fTop);
65        bounds.unionWith(glyphBounds);
66
67        // advance next character
68        SkScalar skWidth;
69        paint.getTextWidths(&glyph, sizeof(glyph), &skWidth, NULL);
70        totalAdvance += skWidth;
71    }
72
73    // apply alignment via x parameter (which JNI layer would have done)
74    if (paint.getTextAlign() == SkPaint::kCenter_Align) {
75        x -= totalAdvance / 2;
76    } else if (paint.getTextAlign() == SkPaint::kRight_Align) {
77        x -= totalAdvance;
78    }
79
80    bounds.translate(x, y);
81
82    // Force left alignment, since alignment offset is already baked in
83    SkPaint alignPaintCopy(paint);
84    alignPaintCopy.setTextAlign(SkPaint::kLeft_Align);
85    canvas->drawText(glyphs.data(), positions.data(), glyphs.size(), alignPaintCopy, x, y,
86                bounds.left, bounds.top, bounds.right, bounds.bottom, totalAdvance);
87}
88
89void TestUtils::drawTextToCanvas(TestCanvas* canvas, const char* text,
90        const SkPaint& paint, const SkPath& path) {
91    // drawing text requires GlyphID TextEncoding (which JNI layer would have done)
92    LOG_ALWAYS_FATAL_IF(paint.getTextEncoding() != SkPaint::kGlyphID_TextEncoding,
93            "must use glyph encoding");
94    SkSurfaceProps surfaceProps(0, kUnknown_SkPixelGeometry);
95    SkAutoGlyphCacheNoGamma autoCache(paint, &surfaceProps, &SkMatrix::I());
96
97    std::vector<glyph_t> glyphs;
98    while (*text != '\0') {
99        SkUnichar unichar = SkUTF8_NextUnichar(&text);
100        glyphs.push_back(autoCache.getCache()->unicharToGlyph(unichar));
101    }
102    canvas->drawTextOnPath(glyphs.data(), glyphs.size(), path, 0, 0, paint);
103}
104
105} /* namespace uirenderer */
106} /* namespace android */
107