#define __SP_GUIDELINE_C__

/*
 * Infinite horizontal/vertical line
 *
 * Author:
 *   Lauris Kaplinski <lauris@kaplinski.com>
 *
 * Copyright (C) 2000-2002 Lauris Kaplinski
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */

#include <math.h>

#include <libnr/nr-matrix.h>
#include <libnr/nr-pixops.h>

#include "sp-canvas-util.h"
#include "guideline.h"

static void sp_guideline_class_init (SPGuideLineClass *klass);
static void sp_guideline_init (SPGuideLine *guideline);
static void sp_guideline_destroy (GtkObject *object);

static void sp_guideline_update (SPCanvasItem *item, double *affine, unsigned int flags);
static void sp_guideline_render (SPCanvasItem *item, SPCanvasBuf *buf);

static double sp_guideline_point (SPCanvasItem *item, double x, double y, SPCanvasItem ** actual_item);

static SPCanvasItemClass *parent_class;

GType
sp_guideline_get_type (void)
{
	static GType guideline_type = 0;

	if (!guideline_type) {
		static const GTypeInfo guideline_info =
		{
			sizeof (SPGuideLineClass),
			NULL, NULL,
			(GClassInitFunc) sp_guideline_class_init,
			NULL, NULL,
			sizeof (SPGuideLine),
			16,
			(GInstanceInitFunc) sp_guideline_init,
			NULL,
		};
		guideline_type = g_type_register_static (SP_TYPE_CANVAS_ITEM, "SPGuideLine", &guideline_info, (GTypeFlags)0);
	}
	return guideline_type;
}

static void
sp_guideline_class_init (SPGuideLineClass *klass)
{
	GObjectClass *g_object_class;
	GtkObjectClass *object_class;
	SPCanvasItemClass *item_class;

	g_object_class = G_OBJECT_CLASS (klass);
	object_class = (GtkObjectClass *) klass;
	item_class = (SPCanvasItemClass *) klass;

	parent_class = (SPCanvasItemClass*)g_type_class_peek_parent (klass);

	object_class->destroy = sp_guideline_destroy;

	item_class->update = sp_guideline_update;
	item_class->render = sp_guideline_render;
	item_class->point = sp_guideline_point;
}

static void
sp_guideline_init (SPGuideLine *gl)
{
	gl->rgba = 0x0000ff7f;

	gl->vertical = 0;
	gl->sensitive = 0;
}

static void
sp_guideline_destroy (GtkObject *object)
{
	GTK_OBJECT_CLASS (parent_class)->destroy (object);
}

static void
sp_guideline_render (SPCanvasItem *item, SPCanvasBuf *buf)
{
	SPGuideLine *gl;
	unsigned int r, g, b, a;
	int p, p0, p1, step;
	unsigned char *d;

	gl = SP_GUIDELINE (item);

	sp_canvas_buf_ensure_buf (buf);
	buf->is_bg = FALSE;

	r = NR_RGBA32_R (gl->rgba);
	g = NR_RGBA32_G (gl->rgba);
	b = NR_RGBA32_B (gl->rgba);
	a = NR_RGBA32_A (gl->rgba);

	if (gl->vertical) {
		if (gl->position < buf->rect.x0) return;
		if (gl->position >= buf->rect.x1) return;
		p0 = buf->rect.y0;
		p1 = buf->rect.y1;
		step = buf->buf_rowstride;
		d = buf->buf + 3 * (gl->position - buf->rect.x0);
	} else {
		if (gl->position < buf->rect.y0) return;
		if (gl->position >= buf->rect.y1) return;
		p0 = buf->rect.x0;
		p1 = buf->rect.x1;
		step = 3;
		d = buf->buf + (gl->position - buf->rect.y0) * buf->buf_rowstride;
	}

	for (p = p0; p < p1; p++) {
		d[0] = NR_COMPOSEN11 (r, a, d[0]);
		d[1] = NR_COMPOSEN11 (g, a, d[1]);
		d[2] = NR_COMPOSEN11 (b, a, d[2]);
		d += step;
	}
}

static void
sp_guideline_update (SPCanvasItem *item, double *affine, unsigned int flags)
{
	SPGuideLine *gl;

	gl = SP_GUIDELINE (item);

	if (((SPCanvasItemClass *) parent_class)->update)
		((SPCanvasItemClass *) parent_class)->update (item, affine, flags);

	if (gl->vertical) {
		gl->position = (int) (affine[4] + 0.5);
		sp_canvas_update_bbox (item, gl->position, -1000000, gl->position + 1, 1000000);
	} else {
		gl->position = (int) (affine[5] + 0.5);
		sp_canvas_update_bbox (item, -1000000, gl->position, 1000000, gl->position + 1);
	}
}

static double
sp_guideline_point (SPCanvasItem *item, double x, double y, SPCanvasItem **actual_item)
{
	SPGuideLine *gl;

	gl = SP_GUIDELINE (item);

	if (!gl->sensitive) return 1e18;

	*actual_item = item;

	if (gl->vertical) {
		return fabs (gl->position - x);
	} else {
		return fabs (gl->position - y);
	}
}

SPCanvasItem *
sp_guideline_new (SPCanvasGroup *parent, double position, unsigned int vertical)
{
	SPCanvasItem *item;
	SPGuideLine *gl;

	item = sp_canvas_item_new (parent, SP_TYPE_GUIDELINE, NULL);

	gl = SP_GUIDELINE (item);

	gl->vertical = vertical;
	sp_guideline_set_position (gl, position);

	return item;
}

void
sp_guideline_set_position (SPGuideLine *gl, double position)
{
	NRMatrix i2b;

	nr_matrix_set_translate (&i2b, position, position);

	sp_canvas_item_affine_absolute (SP_CANVAS_ITEM (gl), NR_MATRIX_D_TO_DOUBLE (&i2b));
}

void
sp_guideline_set_color (SPGuideLine *gl, unsigned int rgba)
{
	gl->rgba = rgba;

	sp_canvas_item_request_update (SP_CANVAS_ITEM (gl));
}

void
sp_guideline_set_sensitive (SPGuideLine *gl, int sensitive)
{
	gl->sensitive = sensitive;
}
