1 | // Copyright (C) 2023 The Qt Company Ltd. |
2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
3 | |
4 | #include "qsggradientcache_p.h" |
5 | |
6 | #include <QtGui/private/qdrawhelper_p.h> |
7 | #include <QtGui/rhi/qrhi.h> |
8 | |
9 | #include <QtQuick/qsgtexture.h> |
10 | #include <QtQuick/private/qsgplaintexture_p.h> |
11 | |
12 | QT_BEGIN_NAMESPACE |
13 | |
14 | static void generateGradientColorTable(const QSGGradientCacheKey &gradient, |
15 | uint *colorTable, int size, float opacity) |
16 | { |
17 | int pos = 0; |
18 | const QGradientStops &s = gradient.stops; |
19 | Q_ASSERT(!s.isEmpty()); |
20 | const bool colorInterpolation = true; |
21 | |
22 | uint alpha = qRound(f: opacity * 256); |
23 | uint current_color = ARGB_COMBINE_ALPHA(s[0].second.rgba(), alpha); |
24 | qreal incr = 1.0 / qreal(size); |
25 | qreal fpos = 1.5 * incr; |
26 | colorTable[pos++] = ARGB2RGBA(x: qPremultiply(x: current_color)); |
27 | |
28 | while (fpos <= s.first().first) { |
29 | colorTable[pos] = colorTable[pos - 1]; |
30 | pos++; |
31 | fpos += incr; |
32 | } |
33 | |
34 | if (colorInterpolation) |
35 | current_color = qPremultiply(x: current_color); |
36 | |
37 | const int sLast = s.size() - 1; |
38 | for (int i = 0; i < sLast; ++i) { |
39 | qreal delta = 1/(s[i+1].first - s[i].first); |
40 | uint next_color = ARGB_COMBINE_ALPHA(s[i + 1].second.rgba(), alpha); |
41 | if (colorInterpolation) |
42 | next_color = qPremultiply(x: next_color); |
43 | |
44 | while (fpos < s[i+1].first && pos < size) { |
45 | int dist = int(256 * ((fpos - s[i].first) * delta)); |
46 | int idist = 256 - dist; |
47 | if (colorInterpolation) |
48 | colorTable[pos] = ARGB2RGBA(x: INTERPOLATE_PIXEL_256(x: current_color, a: idist, y: next_color, b: dist)); |
49 | else |
50 | colorTable[pos] = ARGB2RGBA(x: qPremultiply(x: INTERPOLATE_PIXEL_256(x: current_color, a: idist, y: next_color, b: dist))); |
51 | ++pos; |
52 | fpos += incr; |
53 | } |
54 | current_color = next_color; |
55 | } |
56 | |
57 | uint last_color = ARGB2RGBA(x: qPremultiply(ARGB_COMBINE_ALPHA(s[sLast].second.rgba(), alpha))); |
58 | for ( ; pos < size; ++pos) |
59 | colorTable[pos] = last_color; |
60 | |
61 | colorTable[size-1] = last_color; |
62 | } |
63 | |
64 | QSGGradientCache::~QSGGradientCache() |
65 | { |
66 | qDeleteAll(c: m_textures); |
67 | } |
68 | |
69 | QSGGradientCache *QSGGradientCache::cacheForRhi(QRhi *rhi) |
70 | { |
71 | static QHash<QRhi *, QSGGradientCache *> caches; |
72 | auto it = caches.constFind(key: rhi); |
73 | if (it != caches.constEnd()) |
74 | return *it; |
75 | |
76 | QSGGradientCache *cache = new QSGGradientCache; |
77 | rhi->addCleanupCallback(callback: [cache](QRhi *rhi) { |
78 | caches.remove(key: rhi); |
79 | delete cache; |
80 | }); |
81 | caches.insert(key: rhi, value: cache); |
82 | return cache; |
83 | } |
84 | |
85 | QSGTexture *QSGGradientCache::get(const QSGGradientCacheKey &grad) |
86 | { |
87 | QSGPlainTexture *tx = m_textures[grad]; |
88 | if (!tx) { |
89 | static const int W = 1024; // texture size is 1024x1 |
90 | QImage gradTab(W, 1, QImage::Format_RGBA8888_Premultiplied); |
91 | if (!grad.stops.isEmpty()) |
92 | generateGradientColorTable(gradient: grad, colorTable: reinterpret_cast<uint *>(gradTab.bits()), size: W, opacity: 1.0f); |
93 | else |
94 | gradTab.fill(color: Qt::black); |
95 | tx = new QSGPlainTexture; |
96 | tx->setImage(gradTab); |
97 | switch (grad.spread) { |
98 | case QGradient::PadSpread: |
99 | tx->setHorizontalWrapMode(QSGTexture::ClampToEdge); |
100 | tx->setVerticalWrapMode(QSGTexture::ClampToEdge); |
101 | break; |
102 | case QGradient::RepeatSpread: |
103 | tx->setHorizontalWrapMode(QSGTexture::Repeat); |
104 | tx->setVerticalWrapMode(QSGTexture::Repeat); |
105 | break; |
106 | case QGradient::ReflectSpread: |
107 | tx->setHorizontalWrapMode(QSGTexture::MirroredRepeat); |
108 | tx->setVerticalWrapMode(QSGTexture::MirroredRepeat); |
109 | break; |
110 | default: |
111 | qWarning(msg: "Unknown gradient spread mode %d" , grad.spread); |
112 | break; |
113 | } |
114 | tx->setFiltering(QSGTexture::Linear); |
115 | m_textures[grad] = tx; |
116 | } |
117 | return tx; |
118 | } |
119 | |
120 | |
121 | QT_END_NAMESPACE |
122 | |