MagickExport MagickBooleanType GradientImage(Image *image,
const GradientType type,const SpreadMethod method,
const PixelPacket *start_color,const PixelPacket *stop_color)
{
DrawInfo
*draw_info;
GradientInfo
*gradient;
MagickBooleanType
status;
register ssize_t
i;
/*
Set gradient start-stop end points.
*/
assert(image != (const Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(start_color != (const PixelPacket *) NULL);
assert(stop_color != (const PixelPacket *) NULL);
draw_info=AcquireDrawInfo();
gradient=(&draw_info->gradient);
gradient->type=type;
gradient->bounding_box.width=image->columns;
gradient->bounding_box.height=image->rows;
gradient->gradient_vector.x2=(double) image->columns-1.0;
gradient->gradient_vector.y2=(double) image->rows-1.0;
if ((type == LinearGradient) && (gradient->gradient_vector.y2 != 0.0))
gradient->gradient_vector.x2=0.0;
gradient->center.x=(double) gradient->gradient_vector.x2/2.0;
gradient->center.y=(double) gradient->gradient_vector.y2/2.0;
gradient->radius=MagickMax(gradient->center.x,gradient->center.y);
gradient->spread=method;
/*
Define the gradient to fill between the stops.
*/
gradient->number_stops=2;
gradient->stops=(StopInfo *) AcquireQuantumMemory(gradient->number_stops,
sizeof(*gradient->stops));
if (gradient->stops == (StopInfo *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
(void) ResetMagickMemory(gradient->stops,0,gradient->number_stops*
sizeof(*gradient->stops));
for (i=0; i < (ssize_t) gradient->number_stops; i++)
GetMagickPixelPacket(image,&gradient->stops[i].color);
SetMagickPixelPacket(image,start_color,(IndexPacket *) NULL,
&gradient->stops[0].color);
gradient->stops[0].offset=0.0;
SetMagickPixelPacket(image,stop_color,(IndexPacket *) NULL,
&gradient->stops[1].color);
gradient->stops[1].offset=1.0;
/*
Draw a gradient on the image.
*/
status=DrawGradientImage(image,draw_info);
draw_info=DestroyDrawInfo(draw_info);
if ((start_color->opacity == OpaqueOpacity) &&
(stop_color->opacity == OpaqueOpacity))
image->matte=MagickFalse;
if ((IsGrayPixel(start_color) != MagickFalse) &&
(IsGrayPixel(stop_color) != MagickFalse))
image->type=GrayscaleType;
return(status);
}
MagickExport MagickBooleanType GradientImage(Image *image,
const GradientType type,const SpreadMethod method,const StopInfo *stops,
const size_t number_stops,ExceptionInfo *exception)
{
const char
*artifact;
DrawInfo
*draw_info;
GeometryInfo
geometry_info;
GradientInfo
*gradient;
MagickBooleanType
status;
MagickStatusType
flags;
/*
Set gradient start-stop end points.
*/
assert(image != (const Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(stops != (const StopInfo *) NULL);
assert(number_stops > 0);
draw_info=AcquireDrawInfo();
gradient=(&draw_info->gradient);
gradient->type=type;
gradient->bounding_box.width=image->columns;
gradient->bounding_box.height=image->rows;
artifact=GetImageArtifact(image,"gradient:bounding-box");
if (artifact != (const char *) NULL)
(void) ParseAbsoluteGeometry(artifact,&gradient->bounding_box);
gradient->gradient_vector.x2=(double) image->columns-1.0;
gradient->gradient_vector.y2=(double) image->rows-1.0;
if ((type == LinearGradient) && (gradient->gradient_vector.y2 != 0.0))
gradient->gradient_vector.x2=0.0;
artifact=GetImageArtifact(image,"gradient:vector");
if (artifact != (const char *) NULL)
{
flags=ParseGeometry(artifact,&geometry_info);
gradient->gradient_vector.x1=geometry_info.rho;
if ((flags & SigmaValue) != 0)
gradient->gradient_vector.y1=geometry_info.sigma;
if ((flags & XiValue) != 0)
gradient->gradient_vector.x2=geometry_info.xi;
if ((flags & PsiValue) != 0)
gradient->gradient_vector.y2=geometry_info.psi;
}
gradient->center.x=(double) gradient->gradient_vector.x2/2.0;
gradient->center.y=(double) gradient->gradient_vector.y2/2.0;
artifact=GetImageArtifact(image,"gradient:center");
if (artifact != (const char *) NULL)
{
flags=ParseGeometry(artifact,&geometry_info);
gradient->center.x=geometry_info.rho;
if ((flags & SigmaValue) != 0)
gradient->center.y=geometry_info.sigma;
}
gradient->radius=MagickMax(gradient->center.x,gradient->center.y);
artifact=GetImageArtifact(image,"gradient:radius");
if (artifact != (const char *) NULL)
gradient->radius=StringToDouble(artifact,(char **) NULL);
gradient->spread=method;
/*
Define the gradient to fill between the stops.
*/
gradient->number_stops=number_stops;
gradient->stops=(StopInfo *) AcquireQuantumMemory(gradient->number_stops,
sizeof(*gradient->stops));
if (gradient->stops == (StopInfo *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
(void) CopyMagickMemory(gradient->stops,stops,(size_t) number_stops*
sizeof(*stops));
/*
Draw a gradient on the image.
*/
status=DrawGradientImage(image,draw_info,exception);
draw_info=DestroyDrawInfo(draw_info);
return(status);
}
