gtk/gdk-pixbuf/gdk-pixbuf.c

/*
 * gdk-pixbuf.c: Resource management.
 *
 * Authors:
 *    Miguel de Icaza (miguel@gnu.org)
 *    Mark Crichton (crichton@gimp.org)
 */

#include <config.h>
#include <glib.h>
#include <math.h>
#include <libart_lgpl/art_misc.h>
#include <libart_lgpl/art_affine.h>
#include <libart_lgpl/art_pixbuf.h>
#include <libart_lgpl/art_rgb_pixbuf_affine.h>
#include <libart_lgpl/art_alphagamma.h>
#include "gdk-pixbuf.h"


void
gdk_pixbuf_destroy (GdkPixBuf *pixbuf)
{
     art_pixbuf_free (pixbuf->art_pixbuf);
     pixbuf->art_pixbuf = NULL;
     g_free (pixbuf);
}

GdkPixBuf *
gdk_pixbuf_new (ArtPixBuf          *art_pixbuf,
		GdkPixBufUnrefFunc *unref_fn)
{
	GdkPixBuf *pixbuf;

	if (!art_pixbuf)
		return NULL;

	pixbuf             = g_new (GdkPixBuf, 1);
	pixbuf->ref_count  = 1;
	pixbuf->unref_fn   = unref_fn;
	pixbuf->art_pixbuf = art_pixbuf;

	return pixbuf;
}

void
gdk_pixbuf_ref (GdkPixBuf *pixbuf)
{
     g_return_if_fail (pixbuf != NULL);
     g_return_if_fail (pixbuf->ref_count > 0);

     pixbuf->ref_count++;
}

void
gdk_pixbuf_unref (GdkPixBuf *pixbuf)
{
    g_return_if_fail (pixbuf != NULL);
    g_return_if_fail (pixbuf->ref_count > 0);

    pixbuf->ref_count--;

    if (pixbuf->ref_count == 0)
	gdk_pixbuf_destroy (pixbuf);
}

GdkPixBuf *
gdk_pixbuf_scale (const GdkPixBuf *pixbuf, gint w, gint h)
{
    art_u8 *pixels;
    gint rowstride;
    double affine[6];
    ArtAlphaGamma *alphagamma;
    ArtPixBuf *art_pixbuf = NULL;
    GdkPixBuf *copy = NULL;

    alphagamma = NULL;

    affine[1] = affine[2] = affine[4] = affine[5] = 0;

    affine[0] = w / (double)(pixbuf->art_pixbuf->width);
    affine[3] = h / (double)(pixbuf->art_pixbuf->height);

    /*    rowstride = w * pixbuf->art_pixbuf->n_channels; */
    rowstride = w * 3;

    pixels = art_alloc (h * rowstride);
    art_rgb_pixbuf_affine (pixels, 0, 0, w, h, rowstride,
			   pixbuf->art_pixbuf,
			   affine, ART_FILTER_NEAREST, alphagamma);

    if (pixbuf->art_pixbuf->has_alpha)
	    /* should be rgba */
	    art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, rowstride);
    else
	    art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, rowstride);

    copy = gdk_pixbuf_new (art_pixbuf, NULL);

    if (!copy)
	    art_free (pixels);
    
    return copy;
}

GdkPixBuf *
gdk_pixbuf_duplicate (const GdkPixBuf *pixbuf)
{
	GdkPixBuf *copy  = g_new (GdkPixBuf, 1);

	copy->ref_count  = 1;
	copy->unref_fn   = pixbuf->unref_fn;
	copy->art_pixbuf = art_pixbuf_duplicate (pixbuf->art_pixbuf);

	return copy;
}

GdkPixBuf *
gdk_pixbuf_rotate (GdkPixBuf *pixbuf, gdouble angle)
{
     art_u8 *pixels;
     gint rowstride, w, h;
     gdouble rad;
     double rot[6], trans[6], affine[6];
     ArtAlphaGamma *alphagamma = NULL;
     ArtPixBuf *art_pixbuf = NULL;

     w = pixbuf->art_pixbuf->width;
     h = pixbuf->art_pixbuf->height;

     rad = (M_PI * angle / 180.0);

     rot[0] = cos(rad);
     rot[1] = sin(rad);
     rot[2] = -sin(rad);
     rot[3] = cos(rad);
     rot[4] = rot[5] = 0;

     trans[0] = trans[3] = 1;
     trans[1] = trans[2] = 0;
     trans[4] = -(double)w / 2.0;
     trans[5] = -(double)h / 2.0;

     art_affine_multiply(rot, trans, rot);

     trans[0] = trans[3] = 1;
     trans[1] = trans[2] = 0;
     trans[4] = (double)w / 2.0;
     trans[5] = (double)h / 2.0;

     art_affine_multiply(affine, rot, trans);

     g_print("Affine: %e %e %e %e %e %e\n", affine[0], affine[1], affine[2],
	     affine[3], affine[4], affine[5]);

     /* rowstride = w * pixbuf->art_pixbuf->n_channels; */
     rowstride = w * 3;

     pixels = art_alloc (h * rowstride);
     art_rgb_pixbuf_affine (pixels, 0, 0, w, h, rowstride,
			    pixbuf->art_pixbuf,
			    affine, ART_FILTER_NEAREST, alphagamma);
     if (pixbuf->art_pixbuf->has_alpha)
	  /* should be rgba */
	  art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, rowstride);
     else
	  art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, rowstride);

     art_pixbuf_free (pixbuf->art_pixbuf);
     pixbuf->art_pixbuf = art_pixbuf;

     return pixbuf;
}