summaryrefslogtreecommitdiff
path: root/vcl/opengl/scale.cxx
blob: 98f0f5ea76b81b8454b724e3cc2c65f8c9a0e727 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#include <sal/config.h>
#include <sal/log.hxx>

#include <cmath>

#include <vcl/opengl/OpenGLHelper.hxx>

#include <vcl/bitmap.hxx>

#include <opengl/zone.hxx>
#include <opengl/salbmp.hxx>
#include <opengl/program.hxx>
#include <opengl/texture.hxx>
#include <opengl/RenderState.hxx>

#include <ResampleKernel.hxx>

using vcl::Kernel;
using vcl::Lanczos3Kernel;

bool OpenGLSalBitmap::ImplScaleFilter(
    const rtl::Reference< OpenGLContext > &xContext,
    const double& rScaleX,
    const double& rScaleY,
    GLenum        nFilter )
{
    OpenGLFramebuffer* pFramebuffer;
    OpenGLProgram* pProgram;
    GLenum nOldFilter;
    int nNewWidth( mnWidth * rScaleX );
    int nNewHeight( mnHeight * rScaleY );

    pProgram = xContext->UseProgram( "textureVertexShader",
                                     "textureFragmentShader" );
    if( !pProgram )
        return false;

    OpenGLTexture aNewTex(nNewWidth, nNewHeight);
    pFramebuffer = xContext->AcquireFramebuffer( aNewTex );

    pProgram->SetTexture( "sampler", maTexture );
    nOldFilter = maTexture.GetFilter();
    maTexture.SetFilter( nFilter );
    pProgram->ApplyMatrix(mnWidth, mnHeight);
    pProgram->DrawTexture( maTexture );
    maTexture.SetFilter( nOldFilter );
    pProgram->Clean();

    OpenGLContext::ReleaseFramebuffer( pFramebuffer );

    mnWidth = nNewWidth;
    mnHeight = nNewHeight;
    maTexture = aNewTex;

    CHECK_GL_ERROR();
    return true;
}

void OpenGLSalBitmap::ImplCreateKernel(
    const double& fScale,
    const Kernel& rKernel,
    GLfloat*& pWeights,
    sal_uInt32& aKernelSize )
{
    const double fSamplingRadius(rKernel.GetWidth());
    const double fScaledRadius((fScale < 1.0) ? fSamplingRadius / fScale : fSamplingRadius);
    const double fFilterFactor(std::min(fScale, 1.0));
    int aNumberOfContributions;
    double aSum( 0 );

    aNumberOfContributions = (static_cast< sal_uInt32 >(fabs(ceil(fScaledRadius))) * 2) + 1 - 6;
    aKernelSize = aNumberOfContributions / 2 + 1;

    // avoid a crash for now; re-think me.
    if (aKernelSize > 16)
        aKernelSize = 16;

    pWeights = new GLfloat[16];
    memset( pWeights, 0, 16 * sizeof( GLfloat ) );

    for( sal_uInt32 i(0); i < aKernelSize; i++ )
    {
        const GLfloat aWeight( rKernel.Calculate( fFilterFactor * i ) );
        if( fabs( aWeight ) >= 0.0001 )
        {
            pWeights[i] = aWeight;
            aSum += i > 0 ? aWeight * 2 : aWeight;
        }
    }

    for( sal_uInt32 i(0); i < aKernelSize; i++ )
    {
        pWeights[i] /= aSum;
    }
}

bool OpenGLSalBitmap::ImplScaleConvolution(
    const rtl::Reference< OpenGLContext > &xContext,
    const double& rScaleX,
    const double& rScaleY,
    const Kernel& aKernel )
{
    OpenGLFramebuffer* pFramebuffer;
    OpenGLProgram* pProgram;
    GLfloat* pWeights( nullptr );
    sal_uInt32 nKernelSize;
    GLfloat aOffsets[32];
    int nNewWidth( mnWidth * rScaleX );
    int nNewHeight( mnHeight * rScaleY );

    // TODO Make sure the framebuffer is alright

    pProgram = xContext->UseProgram( "textureVertexShader",
                                      "convolutionFragmentShader" );
    if( pProgram == nullptr )
        return false;

    // horizontal scaling in scratch texture
    if( mnWidth != nNewWidth )
    {
        OpenGLTexture aScratchTex(nNewWidth, nNewHeight);

        pFramebuffer = xContext->AcquireFramebuffer( aScratchTex );

        for( sal_uInt32 i = 0; i < 16; i++ )
        {
            aOffsets[i * 2] = i / static_cast<double>(mnWidth);
            aOffsets[i * 2 + 1] = 0;
        }
        ImplCreateKernel( rScaleX, aKernel, pWeights, nKernelSize );
        pProgram->SetUniform1fv( "kernel", 16, pWeights );
        pProgram->SetUniform2fv( "offsets", 16, aOffsets );
        pProgram->SetTexture( "sampler", maTexture );
        pProgram->DrawTexture( maTexture );
        pProgram->Clean();

        maTexture = aScratchTex;
        OpenGLContext::ReleaseFramebuffer( pFramebuffer );
    }

    // vertical scaling in final texture
    if( mnHeight != nNewHeight )
    {
        OpenGLTexture aScratchTex(nNewWidth, nNewHeight);

        pFramebuffer = xContext->AcquireFramebuffer( aScratchTex );

        for( sal_uInt32 i = 0; i < 16; i++ )
        {
            aOffsets[i * 2] = 0;
            aOffsets[i * 2 + 1] = i / static_cast<double>(mnHeight);
        }
        ImplCreateKernel( rScaleY, aKernel, pWeights, nKernelSize );
        pProgram->SetUniform1fv( "kernel", 16, pWeights );
        pProgram->SetUniform2fv( "offsets", 16, aOffsets );
        pProgram->SetTexture( "sampler", maTexture );
        pProgram->DrawTexture( maTexture );
        pProgram->Clean();

        maTexture = aScratchTex;
        OpenGLContext::ReleaseFramebuffer( pFramebuffer );
    }

    mnWidth = nNewWidth;
    mnHeight = nNewHeight;

    CHECK_GL_ERROR();
    return true;
}

/*
 "Area" scaling algorithm, which seems to give better results for downscaling
 than other algorithms. The principle (taken from opencv, see resize.cl)
 is that each resulting pixel is the average of all the source pixel values
 it represents. Which is trivial in the case of exact multiples for downscaling,
 the generic case needs to also consider that some source pixels contribute
 only partially to their resulting pixels (because of non-integer multiples).
*/
bool OpenGLSalBitmap::ImplScaleArea( const rtl::Reference< OpenGLContext > &xContext,
                                     double rScaleX, double rScaleY )
{
    int nNewWidth( mnWidth * rScaleX );
    int nNewHeight( mnHeight * rScaleY );

    if( nNewWidth == mnWidth && nNewHeight == mnHeight )
        return true;

    double ixscale = 1 / rScaleX;
    double iyscale = 1 / rScaleY;
    bool fast = ( ixscale == std::trunc( ixscale ) && iyscale == std::trunc( iyscale )
        && int( nNewWidth * ixscale ) == mnWidth && int( nNewHeight * iyscale ) == mnHeight );

    bool bTwoPasses = false;

    // The generic case has arrays only up to 100 ratio downscaling, which is hopefully enough
    // in practice, but protect against buffer overflows in case such an extreme case happens
    // (and in such case the precision of the generic algorithm probably doesn't matter anyway).
    if( ixscale > 100 || iyscale > 100 )
    {
        fast = true;
    }
    else
    {
        if (ixscale > 16 || iyscale > 16)
        {
            ixscale = std::floor(std::sqrt(ixscale));
            iyscale = std::floor(std::sqrt(iyscale));
            nNewWidth = int(mnWidth / ixscale);
            rScaleX *= ixscale; // second pass x-scale factor
            nNewHeight = int(mnHeight / iyscale);
            rScaleY *= iyscale; // second pass y-scale factor
            bTwoPasses = true;
        }
    }

    // TODO Make sure the framebuffer is alright

    OString sUseReducedRegisterVariantDefine;
    if (xContext->getOpenGLCapabilitySwitch().mbLimitedShaderRegisters)
        sUseReducedRegisterVariantDefine = OString("#define USE_REDUCED_REGISTER_VARIANT\n");

    OpenGLProgram* pProgram = xContext->UseProgram( "textureVertexShader",
        fast ? OUString( "areaScaleFastFragmentShader" ) : OUString( "areaScaleFragmentShader" ),
        sUseReducedRegisterVariantDefine);

    if( pProgram == nullptr )
        return false;

    OpenGLTexture aScratchTex(nNewWidth, nNewHeight);

    OpenGLFramebuffer* pFramebuffer = xContext->AcquireFramebuffer( aScratchTex );

    // NOTE: This setup is also done in OpenGLSalGraphicsImpl::DrawTransformedTexture().
    if( fast )
    {
        pProgram->SetUniform1i( "xscale", ixscale );
        pProgram->SetUniform1i( "yscale", iyscale );
        // The shader operates on pixels in the surrounding area, so it's necessary
        // to know the step in texture coordinates to get to the next pixel.
        // With a texture atlas the "texture" is just a subtexture of a larger texture,
        // so while with a normal texture we'd map between <0.0,1.0> and <0,mnWidth>,
        // with a subtexture the texture coordinates range is smaller.
        GLfloat srcCoords[ 8 ];
        maTexture.GetWholeCoord( srcCoords );
        pProgram->SetUniform1f( "xstep", ( srcCoords[ 4 ] - srcCoords[ 0 ] ) / mnWidth );
        pProgram->SetUniform1f( "ystep", ( srcCoords[ 5 ] - srcCoords[ 1 ] ) / mnHeight );
        pProgram->SetUniform1f( "ratio", 1.0 / ( ixscale * iyscale ));
    }
    else
    {
        pProgram->SetUniform1f( "xscale", ixscale );
        pProgram->SetUniform1f( "yscale", iyscale );
        pProgram->SetUniform1i( "swidth", mnWidth );
        pProgram->SetUniform1i( "sheight", mnHeight );
        // The shader internally actually operates on pixel coordinates,
        // so it needs to know how to convert to those from the texture coordinates.
        // With a simple texture that would mean converting e.g. between
        // <0,mnWidth-1> and <0.0,1.0> coordinates.
        // However with a texture atlas the "texture" is just a subtexture
        // of a larger texture, so the texture coordinates need offset and ratio
        // conversion too.
        GLfloat srcCoords[ 8 ];
        maTexture.GetWholeCoord( srcCoords );
        pProgram->SetUniform1f( "xoffset", srcCoords[ 0 ] );
        pProgram->SetUniform1f( "yoffset", srcCoords[ 1 ] );
        pProgram->SetUniform1f( "xtopixelratio", nNewWidth / ( srcCoords[ 4 ] - srcCoords[ 0 ] ));
        pProgram->SetUniform1f( "ytopixelratio", nNewHeight / ( srcCoords[ 5 ] - srcCoords[ 1 ] ));
        pProgram->SetUniform1f( "xfrompixelratio", ( srcCoords[ 4 ] - srcCoords[ 0 ] ) / mnWidth );
        pProgram->SetUniform1f( "yfrompixelratio", ( srcCoords[ 5 ] - srcCoords[ 1 ] ) / mnHeight );
    }

    pProgram->SetTexture( "sampler", maTexture );
    pProgram->DrawTexture( maTexture );
    pProgram->Clean();

    OpenGLContext::ReleaseFramebuffer(pFramebuffer);

    CHECK_GL_ERROR();

    if (bTwoPasses)
    {
        mnWidth = nNewWidth;
        mnHeight = nNewHeight;

        nNewWidth = round(mnWidth * rScaleX);
        nNewHeight = round(mnHeight * rScaleY);

        ixscale = 1 / rScaleX;
        iyscale = 1 / rScaleY;

        pProgram = xContext->UseProgram("textureVertexShader", "areaScaleFragmentShader", sUseReducedRegisterVariantDefine);
        if (pProgram == nullptr)
            return false;

        OpenGLTexture aScratchTex2(nNewWidth, nNewHeight);

        pFramebuffer = xContext->AcquireFramebuffer(aScratchTex2);

        pProgram->SetUniform1f("xscale", ixscale);
        pProgram->SetUniform1f("yscale", iyscale);
        pProgram->SetUniform1i("swidth", mnWidth);
        pProgram->SetUniform1i("sheight", mnHeight);

        GLfloat srcCoords[ 8 ];
        aScratchTex.GetWholeCoord( srcCoords );
        pProgram->SetUniform1f( "xoffset", srcCoords[ 0 ] );
        pProgram->SetUniform1f( "yoffset", srcCoords[ 1 ] );
        pProgram->SetUniform1f( "xtopixelratio", nNewWidth / ( srcCoords[ 4 ] - srcCoords[ 0 ] ));
        pProgram->SetUniform1f( "ytopixelratio", nNewHeight / ( srcCoords[ 5 ] - srcCoords[ 1 ] ));
        pProgram->SetUniform1f( "xfrompixelratio", ( srcCoords[ 4 ] - srcCoords[ 0 ] ) / mnWidth );
        pProgram->SetUniform1f( "yfrompixelratio", ( srcCoords[ 5 ] - srcCoords[ 1 ] ) / mnHeight );

        pProgram->SetTexture("sampler", aScratchTex);
        pProgram->DrawTexture(aScratchTex);
        pProgram->Clean();

        OpenGLContext::ReleaseFramebuffer(pFramebuffer);

        CHECK_GL_ERROR();

        maTexture = aScratchTex2;
        mnWidth = nNewWidth;
        mnHeight = nNewHeight;
    }
    else
    {
        maTexture = aScratchTex;
        mnWidth = nNewWidth;
        mnHeight = nNewHeight;
    }

    return true;
}

void OpenGLSalBitmap::ImplScale( const double& rScaleX, const double& rScaleY, BmpScaleFlag nScaleFlag )
{
    VCL_GL_INFO( "::ImplScale" );

    mpUserBuffer.reset();
    OpenGLVCLContextZone aContextZone;
    rtl::Reference<OpenGLContext> xContext = OpenGLContext::getVCLContext();
    xContext->state().scissor().disable();
    xContext->state().stencil().disable();

    if (rScaleX <= 1 && rScaleY <= 1)
    {
        nScaleFlag = BmpScaleFlag::BestQuality;
    }

    if( nScaleFlag == BmpScaleFlag::Fast )
    {
        ImplScaleFilter( xContext, rScaleX, rScaleY, GL_NEAREST );
    }
    else if( nScaleFlag == BmpScaleFlag::BiLinear )
    {
        ImplScaleFilter( xContext, rScaleX, rScaleY, GL_LINEAR );
    }
    else if( nScaleFlag == BmpScaleFlag::Default )
    {
        const Lanczos3Kernel aKernel;

        ImplScaleConvolution( xContext, rScaleX, rScaleY, aKernel );
    }
    else if( nScaleFlag == BmpScaleFlag::BestQuality && rScaleX <= 1 && rScaleY <= 1 )
    { // Use area scaling for best quality, but only if downscaling.
        ImplScaleArea( xContext, rScaleX, rScaleY );
    }
    else if( nScaleFlag == BmpScaleFlag::Lanczos || nScaleFlag == BmpScaleFlag::BestQuality  )
    {
        const Lanczos3Kernel aKernel;

        ImplScaleConvolution( xContext, rScaleX, rScaleY, aKernel );
    }
    else
        SAL_WARN( "vcl.opengl", "Invalid flag for scaling operation" );
}

bool OpenGLSalBitmap::ScalingSupported() const
{
    return true;
}

bool OpenGLSalBitmap::Scale( const double& rScaleX, const double& rScaleY, BmpScaleFlag nScaleFlag )
{
    OpenGLVCLContextZone aContextZone;

    VCL_GL_INFO("::Scale " << int(nScaleFlag)
             << " from " << mnWidth << "x" << mnHeight
             << " to " << (mnWidth * rScaleX) << "x" << (mnHeight * rScaleY) );

    if( nScaleFlag == BmpScaleFlag::Fast ||
        nScaleFlag == BmpScaleFlag::BiLinear ||
        nScaleFlag == BmpScaleFlag::Lanczos ||
        nScaleFlag == BmpScaleFlag::Default ||
        nScaleFlag == BmpScaleFlag::BestQuality )
    {
        ImplScale( rScaleX, rScaleY, nScaleFlag );
        return true;
    }

    return false;
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */