office-gobmx/include/basegfx/utils/gradienttools.hxx
Gabor Kelemen 7ac978c4d1 tdf#146619 Recheck include/basegfx with IWYU
Change-Id: I08dad6ceeaa9e5470491c09f06d819c4c27ec5f3
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/156983
Tested-by: Jenkins
Reviewed-by: Gabor Kelemen <kelemeng@ubuntu.com>
2023-09-21 08:53:31 +02:00

526 lines
18 KiB
C++

/* -*- 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 .
*/
#pragma once
#include <config_options.h>
#include <basegfx/point/b2dpoint.hxx>
#include <basegfx/vector/b2dvector.hxx>
#include <basegfx/matrix/b2dhommatrix.hxx>
#include <basegfx/color/bcolor.hxx>
#include <utility>
#include <basegfx/basegfxdllapi.h>
#include <basegfx/utils/bgradient.hxx>
#include <osl/endian.h>
namespace basegfx { class B2DRange; }
namespace
{
/* Internal helper to convert ::Color from tools::color.hxx to BColor
without the need to link against tools library. Be on the
safe side by using the same union
*/
struct ColorToBColorConverter
{
union {
sal_uInt32 mValue;
struct {
#ifdef OSL_BIGENDIAN
sal_uInt8 T;
sal_uInt8 R;
sal_uInt8 G;
sal_uInt8 B;
#else
sal_uInt8 B;
sal_uInt8 G;
sal_uInt8 R;
sal_uInt8 T;
#endif
};
};
ColorToBColorConverter GetRGBColor() const
{
return {R, G, B};
}
ColorToBColorConverter(sal_uInt32 nColor)
: mValue(nColor)
{ T=0; }
constexpr ColorToBColorConverter(sal_uInt8 nRed, sal_uInt8 nGreen, sal_uInt8 nBlue)
: mValue(sal_uInt32(nBlue) | (sal_uInt32(nGreen) << 8) | (sal_uInt32(nRed) << 16))
{}
explicit ColorToBColorConverter(const basegfx::BColor& rBColor)
: ColorToBColorConverter(
sal_uInt8(std::lround(rBColor.getRed() * 255.0)),
sal_uInt8(std::lround(rBColor.getGreen() * 255.0)),
sal_uInt8(std::lround(rBColor.getBlue() * 255.0)))
{}
basegfx::BColor getBColor() const
{
return basegfx::BColor(R / 255.0, G / 255.0, B / 255.0);
}
constexpr explicit operator sal_Int32() const
{
return sal_Int32(mValue);
}
constexpr explicit operator sal_uInt32() const
{
return mValue;
}
};
}
namespace basegfx
{
/** Gradient definition as used in ODF 1.2
This struct collects all data necessary for rendering ODF
1.2-compatible gradients. Use the createXXXODFGradientInfo()
methods below for initializing from ODF attributes.
*/
class UNLESS_MERGELIBS(BASEGFX_DLLPUBLIC) ODFGradientInfo
{
private:
/** transformation mapping from [0,1]^2 texture coordinate
space to [0,1]^2 shape coordinate space
*/
B2DHomMatrix maTextureTransform;
/** transformation mapping from [0,1]^2 shape coordinate space
to [0,1]^2 texture coordinate space. This is the
transformation commonly used to create gradients from a
scanline rasterizer (put shape u/v coordinates into it, get
texture s/t coordinates out of it)
*/
B2DHomMatrix maBackTextureTransform;
/** Aspect ratio of the gradient. Only used in drawinglayer
for generating nested gradient polygons currently. Already
catered for in the transformations above.
*/
double mfAspectRatio;
/** Requested gradient steps to render. See the
implementations of the getXXXGradientAlpha() methods below,
the semantic differs slightly for the different gradient
types.
*/
sal_uInt32 mnRequestedSteps;
public:
ODFGradientInfo()
: mfAspectRatio(1.0),
mnRequestedSteps(0)
{
}
ODFGradientInfo(
B2DHomMatrix aTextureTransform,
double fAspectRatio,
sal_uInt32 nRequestedSteps)
: maTextureTransform(std::move(aTextureTransform)),
mfAspectRatio(fAspectRatio),
mnRequestedSteps(nRequestedSteps)
{
}
ODFGradientInfo(const ODFGradientInfo& rODFGradientInfo)
: maTextureTransform(rODFGradientInfo.getTextureTransform()),
maBackTextureTransform(rODFGradientInfo.maBackTextureTransform),
mfAspectRatio(rODFGradientInfo.getAspectRatio()),
mnRequestedSteps(rODFGradientInfo.getRequestedSteps())
{
}
ODFGradientInfo& operator=(const ODFGradientInfo& rODFGradientInfo)
{
maTextureTransform = rODFGradientInfo.getTextureTransform();
maBackTextureTransform = rODFGradientInfo.maBackTextureTransform;
mfAspectRatio = rODFGradientInfo.getAspectRatio();
mnRequestedSteps = rODFGradientInfo.getRequestedSteps();
return *this;
}
// compare operator
bool operator==(const ODFGradientInfo& rGeoTexSvx) const;
const B2DHomMatrix& getTextureTransform() const { return maTextureTransform; }
const B2DHomMatrix& getBackTextureTransform() const;
double getAspectRatio() const { return mfAspectRatio; }
sal_uInt32 getRequestedSteps() const { return mnRequestedSteps; }
void setTextureTransform(const B2DHomMatrix& rNew)
{
maTextureTransform = rNew;
maBackTextureTransform.identity();
}
};
namespace utils
{
/* Tooling method to extract data from given BGradient
to ColorStops, doing some corrections, partially based
on given SingleColor.
This is used for export preparations in case these exports
do neither support Start/EndIntensity nor Border settings,
both will be eliminated if possible (see below).
The BGradient rGradient and BColorStops& rColorStops
are both return parameters and may be changed.
This will do quite some preparations for the gradient
as follows:
- It will check for single color (resetting rSingleColor when
this is the case) and return with empty ColorStops
- It will blend ColorStops to Intensity if StartIntensity/
EndIntensity != 100 is set in BGradient, so applying
that value(s) to the gradient directly
- It will adapt to Border if Border != 0 is set at the
given BGradient, so applying that value to the gradient
directly
*/
BASEGFX_DLLPUBLIC void prepareColorStops(
const basegfx::BGradient& rGradient,
BColorStops& rColorStops,
BColor& rSingleColor);
/* Tooling method to synchronize the given ColorStops.
The intention is that a color GradientStops and an
alpha/transparence GradientStops gets synchronized
for export.
For the corrections the single values for color and
alpha may be used, e.g. when ColorStops is given
and not empty, but AlphaStops is empty, it will get
synchronized so that it will have the same number and
offsets in AlphaStops as in ColorStops, but with
the given SingleAlpha as value.
At return it guarantees that both have the same
number of entries with the same StopOffsets, so
that synchronized pair of ColorStops can e.g. be used
to export a Gradient with defined/adapted alpha
being 'coupled' indirectly using the
'FillTransparenceGradient' method (at import time).
*/
BASEGFX_DLLPUBLIC void synchronizeColorStops(
BColorStops& rColorStops,
BColorStops& rAlphaStops,
const BColor& rSingleColor,
const BColor& rSingleAlpha);
/* Helper to calculate numberOfSteps needed to represent
gradient for the given two colors:
- to define only based on color distance, give 0 == nRequestedSteps
as wanted value, so color distance will be used
- if a wanted value of nRequestedSteps is given, it gets synched
against the maximum number of steps defined by the color
distance of the two colors
- a minimum result of 1 is returned which means a single
step -> no real gradient
*/
BASEGFX_DLLPUBLIC sal_uInt32 calculateNumberOfSteps(
sal_uInt32 nRequestedSteps,
const BColor& rStart,
const BColor& rEnd);
/** Create matrix for ODF's linear gradient definition
Note that odf linear gradients are varying in y direction.
@param o_rGradientInfo
Receives the calculated texture transformation matrix (for
use with standard [0,1]x[0,1] texture coordinates)
@param rTargetArea
Output area, needed for aspect ratio calculations and
texture transformation
@param nRequestedSteps
Number of gradient steps (from ODF)
@param fBorder
Width of gradient border (from ODF)
@param fAngle
Gradient angle (from ODF)
*/
BASEGFX_DLLPUBLIC ODFGradientInfo createLinearODFGradientInfo(
const B2DRange& rTargetArea,
sal_uInt32 nRequestedSteps,
double fBorder,
double fAngle);
/** Calculate linear gradient blend value
This method generates you the lerp alpha value for
blending linearly between gradient start and end color,
according to the formula (startCol*(1.0-alpha) + endCol*alpha)
@param rUV
Current uv coordinate. Values outside [0,1] will be
clamped. Assumes gradient color varies along the y axis.
@param rGradInfo
Gradient info, for transformation and number of steps
*/
BASEGFX_DLLPUBLIC double getLinearGradientAlpha(const B2DPoint& rUV,
const ODFGradientInfo& rGradInfo);
/** Create matrix for ODF's axial gradient definition
Note that odf axial gradients are varying in y
direction. Note further that you can map the axial
gradient to a linear gradient (in case you want or need to
avoid an extra gradient renderer), by using
createLinearODFGradientInfo() instead, shifting the
resulting texture transformation by 0.5 to the top and
appending the same stop colors again, but mirrored.
@param o_rGradientInfo
Receives the calculated texture transformation matrix (for
use with standard [0,1]x[0,1] texture coordinates)
@param rTargetArea
Output area, needed for aspect ratio calculations and
texture transformation
@param nRequestedSteps
Number of gradient steps (from ODF)
@param fBorder
Width of gradient border (from ODF)
@param fAngle
Gradient angle (from ODF)
*/
BASEGFX_DLLPUBLIC ODFGradientInfo createAxialODFGradientInfo(
const B2DRange& rTargetArea,
sal_uInt32 nRequestedSteps,
double fBorder,
double fAngle);
/** Calculate axial gradient blend value
This method generates you the lerp alpha value for
blending linearly between gradient start and end color,
according to the formula (startCol*(1.0-alpha) + endCol*alpha)
@param rUV
Current uv coordinate. Values outside [0,1] will be
clamped. Assumes gradient color varies along the y axis.
@param rGradInfo
Gradient info, for transformation and number of steps
*/
BASEGFX_DLLPUBLIC double getAxialGradientAlpha(const B2DPoint& rUV,
const ODFGradientInfo& rGradInfo);
/** Create matrix for ODF's radial gradient definition
@param o_rGradientInfo
Receives the calculated texture transformation matrix (for
use with standard [0,1]x[0,1] texture coordinates)
@param rTargetArea
Output area, needed for aspect ratio calculations and
texture transformation
@param rOffset
Gradient offset value (from ODF)
@param nRequestedSteps
Number of gradient steps (from ODF)
@param fBorder
Width of gradient border (from ODF)
@param fAngle
Gradient angle (from ODF)
*/
BASEGFX_DLLPUBLIC ODFGradientInfo createRadialODFGradientInfo(
const B2DRange& rTargetArea,
const B2DVector& rOffset,
sal_uInt32 nRequestedSteps,
double fBorder);
/** Calculate radial gradient blend value
This method generates you the lerp alpha value for
blending linearly between gradient start and end color,
according to the formula (startCol*(1.0-alpha) + endCol*alpha)
@param rUV
Current uv coordinate. Values outside [0,1] will be
clamped.
@param rGradInfo
Gradient info, for transformation and number of steps
*/
BASEGFX_DLLPUBLIC double getRadialGradientAlpha(const B2DPoint& rUV,
const ODFGradientInfo& rGradInfo);
/** Create matrix for ODF's elliptical gradient definition
@param o_rGradientInfo
Receives the calculated texture transformation matrix (for
use with standard [0,1]x[0,1] texture coordinates)
@param rTargetArea
Output area, needed for aspect ratio calculations and
texture transformation
@param rOffset
Gradient offset value (from ODF)
@param nRequestedSteps
Number of gradient steps (from ODF)
@param fBorder
Width of gradient border (from ODF)
@param fAngle
Gradient angle (from ODF)
*/
BASEGFX_DLLPUBLIC ODFGradientInfo createEllipticalODFGradientInfo(
const B2DRange& rTargetArea,
const B2DVector& rOffset,
sal_uInt32 nRequestedSteps,
double fBorder,
double fAngle);
/** Calculate elliptical gradient blend value
This method generates you the lerp alpha value for
blending linearly between gradient start and end color,
according to the formula (startCol*(1.0-alpha) + endCol*alpha)
@param rUV
Current uv coordinate. Values outside [0,1] will be
clamped.
@param rGradInfo
Gradient info, for transformation and number of steps
*/
BASEGFX_DLLPUBLIC double getEllipticalGradientAlpha(const B2DPoint& rUV,
const ODFGradientInfo& rGradInfo);
/** Create matrix for ODF's square gradient definition
@param o_rGradientInfo
Receives the calculated texture transformation matrix (for
use with standard [0,1]x[0,1] texture coordinates)
@param rTargetArea
Output area, needed for aspect ratio calculations and
texture transformation
@param rOffset
Gradient offset value (from ODF)
@param nRequestedSteps
Number of gradient steps (from ODF)
@param fBorder
Width of gradient border (from ODF)
@param fAngle
Gradient angle (from ODF)
*/
BASEGFX_DLLPUBLIC ODFGradientInfo createSquareODFGradientInfo(
const B2DRange& rTargetArea,
const B2DVector& rOffset,
sal_uInt32 nRequestedSteps,
double fBorder,
double fAngle);
/** Calculate square gradient blend value
This method generates you the lerp alpha value for
blending linearly between gradient start and end color,
according to the formula (startCol*(1.0-alpha) + endCol*alpha)
@param rUV
Current uv coordinate. Values outside [0,1] will be
clamped.
@param rGradInfo
Gradient info, for transformation and number of steps
*/
BASEGFX_DLLPUBLIC double getSquareGradientAlpha(const B2DPoint& rUV,
const ODFGradientInfo& rGradInfo);
/** Create matrix for ODF's rectangular gradient definition
@param o_rGradientInfo
Receives the calculated texture transformation matrix (for
use with standard [0,1]x[0,1] texture coordinates)
@param rTargetArea
Output area, needed for aspect ratio calculations and
texture transformation
@param rOffset
Gradient offset value (from ODF)
@param nRequestedSteps
Number of gradient steps (from ODF)
@param fBorder
Width of gradient border (from ODF)
@param fAngle
Gradient angle (from ODF)
*/
BASEGFX_DLLPUBLIC ODFGradientInfo createRectangularODFGradientInfo(
const B2DRange& rTargetArea,
const B2DVector& rOffset,
sal_uInt32 nRequestedSteps,
double fBorder,
double fAngle);
/** Calculate rectangular gradient blend value
This method generates you the lerp alpha value for
blending linearly between gradient start and end color,
according to the formula (startCol*(1.0-alpha) + endCol*alpha)
@param rUV
Current uv coordinate. Values outside [0,1] will be
clamped.
@param rGradInfo
Gradient info, for transformation and number of steps
*/
BASEGFX_DLLPUBLIC double getRectangularGradientAlpha(const B2DPoint& rUV,
const ODFGradientInfo& rGradInfo);
}
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */