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JUCE/modules/juce_graphics/effects/juce_StackShadowEffect.cpp
LukeSonnox 0945558925
Update juce_StackShadowEffect.cpp
Fixing order of transforms applied when drawing shadow
2022-10-21 11:40:16 +01:00

329 lines
11 KiB
C++

/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2020 - Raw Material Software Limited
JUCE is an open source library subject to commercial or open-source
licensing.
By using JUCE, you agree to the terms of both the JUCE 6 End-User License
Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
End User License Agreement: www.juce.com/juce-6-licence
Privacy Policy: www.juce.com/juce-privacy-policy
Or: You may also use this code under the terms of the GPL v3 (see
www.gnu.org/licenses).
JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
DISCLAIMED.
==============================================================================
*/
namespace juce
{
//=================================================================================
// Code below has been borrowed from the Gin (https://github.com/FigBug/Gin) project.
// Copyright(c) 2018, Roland Rabien
static unsigned short const stackblur_mul[255] =
{
512,512,456,512,328,456,335,512,405,328,271,456,388,335,292,512,
454,405,364,328,298,271,496,456,420,388,360,335,312,292,273,512,
482,454,428,405,383,364,345,328,312,298,284,271,259,496,475,456,
437,420,404,388,374,360,347,335,323,312,302,292,282,273,265,512,
497,482,468,454,441,428,417,405,394,383,373,364,354,345,337,328,
320,312,305,298,291,284,278,271,265,259,507,496,485,475,465,456,
446,437,428,420,412,404,396,388,381,374,367,360,354,347,341,335,
329,323,318,312,307,302,297,292,287,282,278,273,269,265,261,512,
505,497,489,482,475,468,461,454,447,441,435,428,422,417,411,405,
399,394,389,383,378,373,368,364,359,354,350,345,341,337,332,328,
324,320,316,312,309,305,301,298,294,291,287,284,281,278,274,271,
268,265,262,259,257,507,501,496,491,485,480,475,470,465,460,456,
451,446,442,437,433,428,424,420,416,412,408,404,400,396,392,388,
385,381,377,374,370,367,363,360,357,354,350,347,344,341,338,335,
332,329,326,323,320,318,315,312,310,307,304,302,299,297,294,292,
289,287,285,282,280,278,275,273,271,269,267,265,263,261,259
};
static unsigned char const stackblur_shr[255] =
{
9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17,
17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19,
19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,
20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24
};
// The Stack Blur Algorithm was invented by Mario Klingemann,
// mario@quasimondo.com and described here:
// http://incubator.quasimondo.com/processing/fast_blur_deluxe.php
// Stackblur algorithm by Mario Klingemann
// Details here:
// http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html
// C++ implemenation base from:
// https://gist.github.com/benjamin9999/3809142
// http://www.antigrain.com/__code/include/agg_blur.h.html
static void applyStackBlur (Image& img, unsigned int radius)
{
const unsigned int w = (unsigned int)img.getWidth();
const unsigned int h = (unsigned int)img.getHeight();
Image::BitmapData data (img, Image::BitmapData::readWrite);
radius = jlimit (2u, 254u, radius);
unsigned char stack[(254 * 2 + 1) * 1];
unsigned int x, y, xp, yp, i, sp, stack_start;
unsigned char* stack_ptr = nullptr;
unsigned char* src_ptr = nullptr;
unsigned char* dst_ptr = nullptr;
unsigned long sum, sum_in, sum_out;
unsigned int wm = w - 1;
unsigned int hm = h - 1;
unsigned int w1 = (unsigned int) data.lineStride;
unsigned int div = (unsigned int) (radius * 2) + 1;
unsigned int mul_sum = stackblur_mul[radius];
unsigned char shr_sum = stackblur_shr[radius];
for (y = 0; y < h; ++y)
{
sum = sum_in = sum_out = 0;
src_ptr = data.getLinePointer (int (y));
for (i = 0; i <= radius; ++i)
{
stack_ptr = &stack[i];
stack_ptr[0] = src_ptr[0];
sum += src_ptr[0] * (i + 1);
sum_out += src_ptr[0];
}
for (i = 1; i <= radius; ++i)
{
if (i <= wm)
src_ptr += 1;
stack_ptr = &stack[1 * (i + radius)];
stack_ptr[0] = src_ptr[0];
sum += src_ptr[0] * (radius + 1 - i);
sum_in += src_ptr[0];
}
sp = radius;
xp = radius;
if (xp > wm)
xp = wm;
src_ptr = data.getLinePointer (int (y)) + (unsigned int)data.pixelStride * xp;
dst_ptr = data.getLinePointer (int (y));
for (x = 0; x < w; ++x)
{
dst_ptr[0] = (unsigned char)((sum * mul_sum) >> shr_sum);
dst_ptr += 1;
sum -= sum_out;
stack_start = sp + div - radius;
if (stack_start >= div)
stack_start -= div;
stack_ptr = &stack[1 * stack_start];
sum_out -= stack_ptr[0];
if (xp < wm)
{
src_ptr += 1;
++xp;
}
stack_ptr[0] = src_ptr[0];
sum_in += src_ptr[0];
sum += sum_in;
++sp;
if (sp >= div)
sp = 0;
stack_ptr = &stack[sp*1];
sum_out += stack_ptr[0];
sum_in -= stack_ptr[0];
}
}
for (x = 0; x < w; ++x)
{
sum = sum_in = sum_out = 0;
src_ptr = data.getLinePointer (0) + (unsigned int)data.pixelStride * x;
for (i = 0; i <= radius; ++i)
{
stack_ptr = &stack[i * 1];
stack_ptr[0] = src_ptr[0];
sum += src_ptr[0] * (i + 1);
sum_out += src_ptr[0];
}
for (i = 1; i <= radius; ++i)
{
if (i <= hm)
src_ptr += w1;
stack_ptr = &stack[1 * (i + radius)];
stack_ptr[0] = src_ptr[0];
sum += src_ptr[0] * (radius + 1 - i);
sum_in += src_ptr[0];
}
sp = radius;
yp = radius;
if (yp > hm)
yp = hm;
src_ptr = data.getLinePointer (int (yp)) + (unsigned int)data.pixelStride * x;
dst_ptr = data.getLinePointer (0) + (unsigned int)data.pixelStride * x;
for (y = 0; y < h; ++y)
{
dst_ptr[0] = (unsigned char)((sum * mul_sum) >> shr_sum);
dst_ptr += w1;
sum -= sum_out;
stack_start = sp + div - radius;
if (stack_start >= div)
stack_start -= div;
stack_ptr = &stack[1 * stack_start];
sum_out -= stack_ptr[0];
if (yp < hm)
{
src_ptr += w1;
++yp;
}
stack_ptr[0] = src_ptr[0];
sum_in += src_ptr[0];
sum += sum_in;
++sp;
if (sp >= div)
sp = 0;
stack_ptr = &stack[sp * 1];
sum_out += stack_ptr[0];
sum_in -= stack_ptr[0];
}
}
}
//=================================================================================
StackShadow::StackShadow (Colour shadowColour, Point<int> o, const int b, const int s) noexcept
: colour (shadowColour), offset (o), blur (b), spread (s)
{
jassert (blur > 0);
}
void StackShadow::drawOuterShadowForPath (Graphics& g, const Path& path) const
{
jassert (blur > 0);
const auto pathArea = path.getBounds().getSmallestIntegerContainer();
auto area = (pathArea + offset)
.expanded (blur + 1)
.getIntersection (g.getClipBounds().expanded (blur + 1));
if (area.getWidth() > 2 && area.getHeight() > 2)
{
Image renderedPath (Image::SingleChannel, area.getWidth(), area.getHeight(), true);
{
Graphics g2 (renderedPath);
g2.setColour (Colours::white);
auto t = AffineTransform::translation (static_cast<float> (offset.x - area.getX()),
static_cast<float> (offset.y - area.getY()));
auto s = AffineTransform::scale (1.f + (static_cast<float> (spread) / static_cast<float> (pathArea.getWidth())),
1.f + (static_cast<float> (spread) / static_cast<float> (pathArea.getHeight())),
area.getCentreX(),
area.getCentreY());
g2.fillPath (path, s.followedBy (t));
}
applyStackBlur (renderedPath, blur);
g.setColour (colour);
g.drawImageAt (renderedPath, area.getX(), area.getY(), true);
}
}
void StackShadow::drawInnerShadowForPath (Graphics& g, const Path& path) const
{
jassert (blur > 0);
jassert (spread >= 0);
const auto pathArea = path.getBounds().getSmallestIntegerContainer();
auto area = (pathArea + offset)
.expanded (blur + 1)
.getIntersection (g.getClipBounds().expanded (blur + 1));
if (area.getWidth() > 2 && area.getHeight() > 2)
{
Image renderedPath (Image::SingleChannel, area.getWidth(), area.getHeight(), true);
{
Graphics g2 (renderedPath);
g2.setColour (Colours::white);
auto t = AffineTransform::translation (static_cast<float> (offset.x - area.getX()),
static_cast<float> (offset.y - area.getY()));
auto s = AffineTransform::scale (1.f - (static_cast<float> (spread) / static_cast<float> (pathArea.getWidth())),
1.f - (static_cast<float> (spread) / static_cast<float> (pathArea.getHeight())),
area.getCentreX(),
area.getCentreY());
g2.strokePath (path, PathStrokeType (static_cast<float> (2 * spread + 1)), s.followedBy(t));
}
applyStackBlur (renderedPath, blur);
Graphics::ScopedSaveState save (g);
g.reduceClipRegion (path);
g.setColour (colour);
g.drawImageAt (renderedPath, area.getX(), area.getY(), true);
}
}
} // namespace juce