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39
40#ifndef QCOLORTRCLUT_P_H
41#define QCOLORTRCLUT_P_H
42
43//
44// W A R N I N G
45// -------------
46//
47// This file is not part of the Qt API. It exists purely as an
48// implementation detail. This header file may change from version to
49// version without notice, or even be removed.
50//
51// We mean it.
52//
53
54#include <QtGui/private/qtguiglobal_p.h>
55#include <QtCore/qsharedpointer.h>
56#include <QtGui/qrgb.h>
57#include <QtGui/qrgba64.h>
58
59#include <cmath>
60
61#if defined(__SSE2__)
62#include <emmintrin.h>
63#elif defined(__ARM_NEON__) || defined(__ARM_NEON)
64#include <arm_neon.h>
65#endif
66
67QT_BEGIN_NAMESPACE
68
69class QColorTransferFunction;
70class QColorTransferTable;
71
72class Q_GUI_EXPORT QColorTrcLut : public QEnableSharedFromThis<QColorTrcLut>
73{
74public:
75 static QColorTrcLut *fromGamma(qreal gamma);
76 static QColorTrcLut *fromTransferFunction(const QColorTransferFunction &transfn);
77 static QColorTrcLut *fromTransferTable(const QColorTransferTable &transTable);
78
79 // The following methods all convert opaque or unpremultiplied colors:
80
81 QRgba64 toLinear64(QRgb rgb32) const
82 {
83#if defined(__SSE2__)
84 __m128i v = _mm_cvtsi32_si128(a: rgb32);
85 v = _mm_unpacklo_epi8(a: v, b: _mm_setzero_si128());
86 const __m128i vidx = _mm_slli_epi16(a: v, count: 4);
87 const int ridx = _mm_extract_epi16(vidx, 2);
88 const int gidx = _mm_extract_epi16(vidx, 1);
89 const int bidx = _mm_extract_epi16(vidx, 0);
90 v = _mm_slli_epi16(a: v, count: 8); // a * 256
91 v = _mm_insert_epi16(v, m_toLinear[ridx], 0);
92 v = _mm_insert_epi16(v, m_toLinear[gidx], 1);
93 v = _mm_insert_epi16(v, m_toLinear[bidx], 2);
94 v = _mm_add_epi16(a: v, b: _mm_srli_epi16(a: v, count: 8));
95 QRgba64 rgba64;
96 _mm_storel_epi64(p: reinterpret_cast<__m128i *>(&rgba64), a: v);
97 return rgba64;
98#elif (defined(__ARM_NEON__) || defined(__ARM_NEON)) && Q_BYTE_ORDER == Q_LITTLE_ENDIAN
99 uint8x8_t v8 = vreinterpret_u8_u32(vmov_n_u32(rgb32));
100 uint16x4_t v16 = vget_low_u16(vmovl_u8(v8));
101 const uint16x4_t vidx = vshl_n_u16(v16, 4);
102 const int ridx = vget_lane_u16(vidx, 2);
103 const int gidx = vget_lane_u16(vidx, 1);
104 const int bidx = vget_lane_u16(vidx, 0);
105 v16 = vshl_n_u16(v16, 8); // a * 256
106 v16 = vset_lane_u16(m_toLinear[ridx], v16, 0);
107 v16 = vset_lane_u16(m_toLinear[gidx], v16, 1);
108 v16 = vset_lane_u16(m_toLinear[bidx], v16, 2);
109 v16 = vadd_u16(v16, vshr_n_u16(v16, 8));
110 return QRgba64::fromRgba64(vget_lane_u64(vreinterpret_u64_u16(v16), 0));
111#else
112 uint r = m_toLinear[qRed(rgb32) << 4];
113 uint g = m_toLinear[qGreen(rgb32) << 4];
114 uint b = m_toLinear[qBlue(rgb32) << 4];
115 r = r + (r >> 8);
116 g = g + (g >> 8);
117 b = b + (b >> 8);
118 return QRgba64::fromRgba64(r, g, b, qAlpha(rgb32) * 257);
119#endif
120 }
121
122 QRgb toLinear(QRgb rgb32) const
123 {
124 return convertWithTable(rgb32, table: m_toLinear);
125 }
126
127 QRgba64 toLinear(QRgba64 rgb64) const
128 {
129 return convertWithTable(rgb64, table: m_toLinear);
130 }
131
132 float u8ToLinearF32(int c) const
133 {
134 ushort v = m_toLinear[c << 4];
135 return v * (1.0f / (255*256));
136 }
137
138 float u16ToLinearF32(int c) const
139 {
140 c -= (c >> 8);
141 ushort v = m_toLinear[c >> 4];
142 return v * (1.0f / (255*256));
143 }
144
145 float toLinear(float f) const
146 {
147 ushort v = m_toLinear[(int)(f * (255 * 16) + 0.5f)];
148 return v * (1.0f / (255*256));
149 }
150
151 QRgb fromLinear64(QRgba64 rgb64) const
152 {
153#if defined(__SSE2__)
154 __m128i v = _mm_loadl_epi64(p: reinterpret_cast<const __m128i *>(&rgb64));
155 v = _mm_sub_epi16(a: v, b: _mm_srli_epi16(a: v, count: 8));
156 const __m128i vidx = _mm_srli_epi16(a: v, count: 4);
157 const int ridx = _mm_extract_epi16(vidx, 0);
158 const int gidx = _mm_extract_epi16(vidx, 1);
159 const int bidx = _mm_extract_epi16(vidx, 2);
160 v = _mm_insert_epi16(v, m_fromLinear[ridx], 2);
161 v = _mm_insert_epi16(v, m_fromLinear[gidx], 1);
162 v = _mm_insert_epi16(v, m_fromLinear[bidx], 0);
163 v = _mm_add_epi16(a: v, b: _mm_set1_epi16(w: 0x80));
164 v = _mm_srli_epi16(a: v, count: 8);
165 v = _mm_packus_epi16(a: v, b: v);
166 return _mm_cvtsi128_si32(a: v);
167#elif (defined(__ARM_NEON__) || defined(__ARM_NEON)) && Q_BYTE_ORDER == Q_LITTLE_ENDIAN
168 uint16x4_t v = vreinterpret_u16_u64(vmov_n_u64(rgb64));
169 v = vsub_u16(v, vshr_n_u16(v, 8));
170 const uint16x4_t vidx = vshr_n_u16(v, 4);
171 const int ridx = vget_lane_u16(vidx, 0);
172 const int gidx = vget_lane_u16(vidx, 1);
173 const int bidx = vget_lane_u16(vidx, 2);
174 v = vset_lane_u16(m_fromLinear[ridx], v, 2);
175 v = vset_lane_u16(m_fromLinear[gidx], v, 1);
176 v = vset_lane_u16(m_fromLinear[bidx], v, 0);
177 uint8x8_t v8 = vrshrn_n_u16(vcombine_u16(v, v), 8);
178 return vget_lane_u32(vreinterpret_u32_u8(v8), 0);
179#else
180 uint a = rgb64.alpha();
181 uint r = rgb64.red();
182 uint g = rgb64.green();
183 uint b = rgb64.blue();
184 a = a - (a >> 8);
185 r = r - (r >> 8);
186 g = g - (g >> 8);
187 b = b - (b >> 8);
188 a = (a + 0x80) >> 8;
189 r = (m_fromLinear[r >> 4] + 0x80) >> 8;
190 g = (m_fromLinear[g >> 4] + 0x80) >> 8;
191 b = (m_fromLinear[b >> 4] + 0x80) >> 8;
192 return (a << 24) | (r << 16) | (g << 8) | b;
193#endif
194 }
195
196 QRgb fromLinear(QRgb rgb32) const
197 {
198 return convertWithTable(rgb32, table: m_fromLinear);
199 }
200
201 QRgba64 fromLinear(QRgba64 rgb64) const
202 {
203 return convertWithTable(rgb64, table: m_fromLinear);
204 }
205
206 int u8FromLinearF32(float f) const
207 {
208 ushort v = m_fromLinear[(int)(f * (255 * 16) + 0.5f)];
209 return (v + 0x80) >> 8;
210 }
211 int u16FromLinearF32(float f) const
212 {
213 ushort v = m_fromLinear[(int)(f * (255 * 16) + 0.5f)];
214 return v + (v >> 8);
215 }
216 float fromLinear(float f) const
217 {
218 ushort v = m_fromLinear[(int)(f * (255 * 16) + 0.5f)];
219 return v * (1.0f / (255*256));
220 }
221
222 // We translate to 0-65280 (255*256) instead to 0-65535 to make simple
223 // shifting an accurate conversion.
224 // We translate from 0-4080 (255*16) for the same speed up, and to keep
225 // the tables small enough to fit in most inner caches.
226 ushort m_toLinear[(255 * 16) + 1]; // [0-4080] -> [0-65280]
227 ushort m_fromLinear[(255 * 16) + 1]; // [0-4080] -> [0-65280]
228
229private:
230 QColorTrcLut() { }
231
232 Q_ALWAYS_INLINE static QRgb convertWithTable(QRgb rgb32, const ushort *table)
233 {
234 const int r = (table[qRed(rgb: rgb32) << 4] + 0x80) >> 8;
235 const int g = (table[qGreen(rgb: rgb32) << 4] + 0x80) >> 8;
236 const int b = (table[qBlue(rgb: rgb32) << 4] + 0x80) >> 8;
237 return (rgb32 & 0xff000000) | (r << 16) | (g << 8) | b;
238 }
239 Q_ALWAYS_INLINE static QRgba64 convertWithTable(QRgba64 rgb64, const ushort *table)
240 {
241#if defined(__SSE2__)
242 __m128i v = _mm_loadl_epi64(p: reinterpret_cast<const __m128i *>(&rgb64));
243 v = _mm_sub_epi16(a: v, b: _mm_srli_epi16(a: v, count: 8));
244 const __m128i vidx = _mm_srli_epi16(a: v, count: 4);
245 const int ridx = _mm_extract_epi16(vidx, 2);
246 const int gidx = _mm_extract_epi16(vidx, 1);
247 const int bidx = _mm_extract_epi16(vidx, 0);
248 v = _mm_insert_epi16(v, table[ridx], 2);
249 v = _mm_insert_epi16(v, table[gidx], 1);
250 v = _mm_insert_epi16(v, table[bidx], 0);
251 v = _mm_add_epi16(a: v, b: _mm_srli_epi16(a: v, count: 8));
252 QRgba64 rgba64;
253 _mm_storel_epi64(p: reinterpret_cast<__m128i *>(&rgba64), a: v);
254 return rgba64;
255#elif (defined(__ARM_NEON__) || defined(__ARM_NEON)) && Q_BYTE_ORDER == Q_LITTLE_ENDIAN
256 uint16x4_t v = vreinterpret_u16_u64(vmov_n_u64(rgb64));
257 v = vsub_u16(v, vshr_n_u16(v, 8));
258 const uint16x4_t vidx = vshr_n_u16(v, 4);
259 const int ridx = vget_lane_u16(vidx, 2);
260 const int gidx = vget_lane_u16(vidx, 1);
261 const int bidx = vget_lane_u16(vidx, 0);
262 v = vset_lane_u16(table[ridx], v, 2);
263 v = vset_lane_u16(table[gidx], v, 1);
264 v = vset_lane_u16(table[bidx], v, 0);
265 v = vadd_u16(v, vshr_n_u16(v, 8));
266 return QRgba64::fromRgba64(vget_lane_u64(vreinterpret_u64_u16(v), 0));
267#else
268 ushort r = rgb64.red();
269 ushort g = rgb64.green();
270 ushort b = rgb64.blue();
271 r = r - (r >> 8);
272 g = g - (g >> 8);
273 b = b - (b >> 8);
274 r = table[r >> 4];
275 g = table[g >> 4];
276 b = table[b >> 4];
277 r = r + (r >> 8);
278 g = g + (g >> 8);
279 b = b + (b >> 8);
280 return QRgba64::fromRgba64(r, g, b, rgb64.alpha());
281#endif
282 }
283};
284
285QT_END_NAMESPACE
286
287#endif // QCOLORTRCLUT_P_H
288

source code of qtbase/src/gui/painting/qcolortrclut_p.h