How can I fill a primitive with an image using DrawingWand

[fisheggs]

The convert command

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convert -size 64x64 xc:blue -tile tile_weave.gif -draw 'circle 32,32 8,32' out.png

Will make an image like this: How can I do the same using the MagickWand/DrawingWand API?

The "-size 64x64 xc:blue" and "-draw 'circle 32,32 8,32'" bits are easy, it's the "-tile tile_weave.gif" I'm having problems with.

[el_supremo]

I've never used it but I think it's MagickTextureImage:

MagickWand *MagickTextureImage(MagickWand *wand, const MagickWand *texture_wand)
% MagickTextureImage() repeatedly tiles the texture image across and down the
% image canvas.

Pete

[fisheggs]

Thanks for the suggestion Pete,

but that tiles on the canvas, rather than fill-tiling on the primitive so I get
rather than

It looks like MagickTextureImage() is the equivalent to the "-texture" operator, eg

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montage -texture tile_weave.gif rose: out.png

looks like

[el_supremo]

I figured out how to do it but, as far as I can determine, there isn't a way to do it directly with Magick/DrawingWand.

I used different filenames, colours, sizes, etc. and this code is a mixture of MagickCore and Magick/DrawingWand but I think it does what you want:

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#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <wand/magick_wand.h>
#include <wand/magick-wand-private.h>

void test_wand(LPTSTR lpCmdLine)
{
	MagickWand *m_wand = NULL;
	PixelWand *p_wand;
	DrawingWand *d_wand;

	ImageInfo *read_info;

	DrawInfo *draw_info;

	ExceptionInfo exception;

	GetExceptionInfo(&exception);
//	unsigned long i_num;
//	char msg[512];

	MagickWandGenesis();

	m_wand = NewMagickWand();
	p_wand = NewPixelWand();
	d_wand = NewDrawingWand();

// Create a new image
	PixelSetColor(p_wand,"blue");
	MagickNewImage(m_wand,640,640,p_wand);

// Draw the circle
	DrawCircle(d_wand,320,320,320,600);

// Now "peek" at the wand
	draw_info = PeekDrawingWand(d_wand);
	read_info=CloneImageInfo(NULL);

// Put the name of the tile into the read_info
    (void) CopyMagickString(read_info->filename,"zssa_p015_tile.png",MaxTextExtent);

// and then read the tile in to the fill_pattern
	draw_info->fill_pattern = ReadImage(read_info,&exception);
	read_info=DestroyImageInfo(read_info);

// Now draw the whole thing 
	DrawImage(m_wand->images,draw_info);

	MagickWriteImage(m_wand,"zssa_tile_c.png");

	/* Destroy everything */
	DestroyExceptionInfo(&exception);
	m_wand = DestroyMagickWand(m_wand);
	p_wand = DestroyPixelWand(p_wand);
	d_wand = DestroyDrawingWand(d_wand);
	MagickWandTerminus();
}

Pete

[fisheggs]

Thanks Pete,
you pointed me to the right place to look.

I have found out how to do it with just the MagickWand API (and without touching <wand/magick-wand-private.h>).

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# without declarations or error checks

i_wand=NewMagickWand()  # base image
t_wand=NewMagickWand()  # image to tile with
d_wand=NewDrawingWand()
p_wand=NewPixelWand()

PixelSetColor(p_wand, "blue")
MagickNewImage(i_wand, 64, 64, p_wand)      # base image, 64x64 blue
MagickReadImage(t_wand, "tile_weave.gif")   # tile image

#
# *THIS* is the bit I couldn't figure out
#
DrawPushPattern(d_wand, "pick-a-name-any-name", 0, 0, 16, 16)  # tile_weave is 16x16
DrawComposite(d_wand, SrcOverCompositeOp, 0, 0, 0, 0, t_wand)
DrawPopPattern(d_wand)
DrawSetFillPatternURL(d_wand, "#pick-a-name-any-name")  # as above but with a '#'

# now draw circle
DrawCircle(d_wand, 32, 32, 8, 32)
MagickDrawImage(i_wand, d_wand)

# and write image
MagickWriteImages(i_wand, "64x64_blue_tile_wand_circle.png", 1)

I think I overlooked DrawSetFillPatternURL() because of the 'URL' in the name.

Anyway the result is compared to the convert generated so I'm happy.

(And off to log a bug against DrawSetFillPatternURL() which ALLWAYS returns MagickFalse.)

Thanks again

[el_supremo]

Well done
I tried DrawSetFillPatternURL but couldn't get it to work.

Pete