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/*
% Copyright (C) 2003 - 2019 GraphicsMagick Group
% Copyright (C) 2003 ImageMagick Studio
% Copyright 1991-1999 E. I. du Pont de Nemours and Company
%
% This program is covered by multiple licenses, which are described in
% Copyright.txt. You should have received a copy of Copyright.txt with this
% package; otherwise see http://www.graphicsmagick.org/www/Copyright.html.
%
% GraphicsMagick Gradient Image Methods.
%
*/
/*
Include declarations.
*/
#include "magick/studio.h"
#include "magick/alpha_composite.h"
#include "magick/color.h"
#include "magick/gradient.h"
#include "magick/monitor.h"
#include "magick/pixel_cache.h"
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
+ G r a d i e n t I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GradientImage() applies a continuously smooth color transitions along a
% vector from one color to another.
%
% Note, the interface of this method will change in the future to support
% more than one transistion.
%
% The format of the GradientImage method is:
%
% MagickPassFail GradientImage(Image *image,
% const PixelPacket *start_color,
% const PixelPacket *stop_color)
%
% A description of each parameter follows:
%
% o image: The image.
%
% o start_color: The start color.
%
% o stop_color: The stop color.
%
%
*/
#define GradientImageText "[%s] Gradient..."
MagickExport MagickPassFail GradientImage(Image *restrict image,
const PixelPacket *start_color,
const PixelPacket *stop_color)
{
const unsigned long
image_rows=image->rows,
image_columns=image->columns;
long
y;
unsigned long
row_count=0;
MagickBool
monitor_active;
MagickPassFail
status=MagickPass;
/*
Determine (Hue, Saturation, Brightness) gradient.
*/
assert(image != (const Image *) NULL);
assert(image->signature == MagickSignature);
assert(start_color != (const PixelPacket *) NULL);
assert(stop_color != (const PixelPacket *) NULL);
monitor_active=MagickMonitorActive();
/*
Generate gradient pixels.
*/
#if defined(HAVE_OPENMP)
# pragma omp parallel for shared(row_count, status)
#endif
for (y=0; y < (long) image->rows; y++)
{
MagickPassFail
thread_status;
register long
x;
register PixelPacket
*q;
thread_status=status;
if (thread_status == MagickFail)
continue;
q=SetImagePixelsEx(image,0,y,image->columns,1,&image->exception);
if (q == (PixelPacket *) NULL)
thread_status=MagickFail;
if (q != (PixelPacket *) NULL)
{
for (x=0; x < (long) image->columns; x++)
{
BlendCompositePixel(&q[x],start_color,stop_color,(double)
MaxRGB*(y*image_columns+x)/(image_columns*image_rows));
}
if (!SyncImagePixelsEx(image,&image->exception))
thread_status=MagickFail;
}
if (monitor_active)
{
unsigned long
thread_row_count;
#if defined(HAVE_OPENMP)
# pragma omp atomic
#endif
row_count++;
#if defined(HAVE_OPENMP)
# pragma omp flush (row_count)
#endif
thread_row_count=row_count;
if (QuantumTick(thread_row_count,image->rows))
if (!MagickMonitorFormatted(thread_row_count,image->rows,&image->exception,
GradientImageText,image->filename))
thread_status=MagickFail;
}
if (thread_status == MagickFail)
{
status=MagickFail;
#if defined(HAVE_OPENMP)
# pragma omp flush (status)
#endif
}
}
if (IsGray(*start_color) && IsGray(*stop_color))
image->is_grayscale=MagickTrue;
if (IsMonochrome(*start_color) && ColorMatch(start_color,stop_color))
image->is_monochrome=MagickTrue;
return(status);
}
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