xenocara/xserver/randr/rrtransform.c

/*
 * Copyright © 2007 Keith Packard
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#include "randrstr.h"
#include "rrtransform.h"

void
RRTransformInit (RRTransformPtr transform)
{
    pixman_transform_init_identity (&transform->transform);
    pixman_f_transform_init_identity (&transform->f_transform);
    pixman_f_transform_init_identity (&transform->f_inverse);
    transform->filter = NULL;
    transform->params = NULL;
    transform->nparams = 0;
}

void
RRTransformFini (RRTransformPtr transform)
{
    free(transform->params);
}

Bool
RRTransformEqual (RRTransformPtr a, RRTransformPtr b)
{
    if (a && pixman_transform_is_identity (&a->transform))
	a = NULL;
    if (b && pixman_transform_is_identity (&b->transform))
	b = NULL;
    if (a == NULL && b == NULL)
	return TRUE;
    if (a == NULL || b == NULL)
	return FALSE;
    if (memcmp (&a->transform, &b->transform, sizeof (a->transform)) != 0)
	return FALSE;
    if (a->filter != b->filter)
	return FALSE;
    if (a->nparams != b->nparams)
	return FALSE;
    if (memcmp (a->params, b->params, a->nparams * sizeof (xFixed)) != 0)
	return FALSE;
    return TRUE;
}

Bool
RRTransformSetFilter (RRTransformPtr	dst,
		      PictFilterPtr	filter,
		      xFixed		*params,
		      int		nparams,
		      int		width,
		      int		height)
{
    xFixed  *new_params;

    if (nparams)
    {
	new_params = malloc(nparams * sizeof (xFixed));
	if (!new_params)
	    return FALSE;
	memcpy (new_params, params, nparams * sizeof (xFixed));
    }
    else
	new_params = NULL;
    free(dst->params);
    dst->filter = filter;
    dst->params = new_params;
    dst->nparams = nparams;
    dst->width = width;
    dst->height = height;
    return TRUE;
}

Bool
RRTransformCopy (RRTransformPtr dst, RRTransformPtr src)
{
    if (src && pixman_transform_is_identity (&src->transform))
	src = NULL;

    if (src)
    {
	if (!RRTransformSetFilter (dst, src->filter,
				   src->params, src->nparams, src->width, src->height))
	    return FALSE;
	dst->transform = src->transform;
	dst->f_transform = src->f_transform;
	dst->f_inverse = src->f_inverse;
    }
    else
    {
	if (!RRTransformSetFilter (dst, NULL, NULL, 0, 0, 0))
	    return FALSE;
	pixman_transform_init_identity (&dst->transform);
	pixman_f_transform_init_identity (&dst->f_transform);
	pixman_f_transform_init_identity (&dst->f_inverse);
    }
    return TRUE;
}

#define F(x)	IntToxFixed(x)

static void
RRTransformRescale(struct pixman_f_transform *f_transform, double limit)
{
    double max = 0, v, scale;
    int i, j;

    for (j = 0; j < 3; j++)
	for (i = 0; i < 3; i++)
	    if ((v = abs (f_transform->m[j][i])) > max)
		max = v;
    scale = limit / max;
    for (j = 0; j < 3; j++)
	for (i = 0; i < 3; i++)
	    f_transform->m[j][i] *= scale;
}

/*
 * Compute the complete transformation matrix including
 * client-specified transform, rotation/reflection values and the crtc 
 * offset.
 *
 * Return TRUE if the resulting transform is not a simple translation.
 */
Bool
RRTransformCompute (int			    x,
		    int			    y,
		    int			    width,
		    int			    height,
		    Rotation		    rotation,
		    RRTransformPtr	    rr_transform,

		    PictTransformPtr	    transform,
		    struct pixman_f_transform *f_transform,
		    struct pixman_f_transform *f_inverse)
{
    PictTransform	    t_transform, inverse;
    struct pixman_f_transform tf_transform, tf_inverse;
    Bool		    overflow = FALSE;

    if (!transform) transform = &t_transform;
    if (!f_transform) f_transform = &tf_transform;
    if (!f_inverse) f_inverse = &tf_inverse;

    pixman_transform_init_identity (transform);
    pixman_transform_init_identity (&inverse);
    pixman_f_transform_init_identity (f_transform);
    pixman_f_transform_init_identity (f_inverse);
    if (rotation != RR_Rotate_0)
    {
	double	f_rot_cos, f_rot_sin, f_rot_dx, f_rot_dy;
	double	f_scale_x, f_scale_y, f_scale_dx, f_scale_dy;
	xFixed	rot_cos, rot_sin, rot_dx, rot_dy;
	xFixed	scale_x, scale_y, scale_dx, scale_dy;

	/* rotation */
	switch (rotation & 0xf) {
	default:
	case RR_Rotate_0:
	    f_rot_cos = 1;	    f_rot_sin = 0;
	    f_rot_dx  = 0;	    f_rot_dy  = 0;
	    rot_cos = F ( 1);	    rot_sin = F ( 0);
	    rot_dx  = F ( 0);	    rot_dy  = F ( 0);
	    break;
	case RR_Rotate_90:
	    f_rot_cos = 0;	    f_rot_sin = 1;
	    f_rot_dx  = height;	    f_rot_dy  = 0;
	    rot_cos = F ( 0);	    rot_sin = F ( 1);
	    rot_dx =  F ( height);  rot_dy  = F (0);
	    break;
	case RR_Rotate_180:
	    f_rot_cos = -1;	    f_rot_sin = 0;
	    f_rot_dx  = width;	    f_rot_dy  = height;
	    rot_cos = F (-1);	    rot_sin = F ( 0);
	    rot_dx  = F (width);   rot_dy  = F ( height);
	    break;
	case RR_Rotate_270:
	    f_rot_cos = 0;	    f_rot_sin = -1;
	    f_rot_dx  = 0;	    f_rot_dy  = width;
	    rot_cos = F ( 0);	    rot_sin = F (-1);
	    rot_dx  = F ( 0);	    rot_dy  = F ( width);
	    break;
	}
	
	pixman_transform_rotate (transform, &inverse, rot_cos, rot_sin);
	pixman_transform_translate (transform, &inverse, rot_dx, rot_dy);
	pixman_f_transform_rotate (f_transform, f_inverse, f_rot_cos, f_rot_sin);
	pixman_f_transform_translate (f_transform, f_inverse, f_rot_dx, f_rot_dy);

	/* reflection */
	f_scale_x = 1;
	f_scale_dx = 0;
	f_scale_y = 1;
	f_scale_dy = 0;
	scale_x = F (1);
	scale_dx = 0;
	scale_y = F (1);
	scale_dy = 0;
	if (rotation & RR_Reflect_X)
	{
	    f_scale_x = -1;
	    scale_x = F(-1);
	    if (rotation & (RR_Rotate_0|RR_Rotate_180)) {
		f_scale_dx = width;
		scale_dx = F(width);
	    } else {
		f_scale_dx = height;
		scale_dx = F(height);
	    }
	}
	if (rotation & RR_Reflect_Y)
	{
	    f_scale_y = -1;
	    scale_y = F(-1);
	    if (rotation & (RR_Rotate_0|RR_Rotate_180)) {
		f_scale_dy = height;
		scale_dy = F(height);
	    } else {
		f_scale_dy = width;
		scale_dy = F(width);
	    }
	}
	
	pixman_transform_scale (transform, &inverse, scale_x, scale_y);
	pixman_f_transform_scale (f_transform, f_inverse, f_scale_x, f_scale_y);
	pixman_transform_translate (transform, &inverse, scale_dx, scale_dy);
	pixman_f_transform_translate (f_transform, f_inverse, f_scale_dx, f_scale_dy);
    }
    
#ifdef RANDR_12_INTERFACE
    if (rr_transform)
    {
        if (!pixman_transform_multiply (transform, &rr_transform->transform, transform))
	    overflow = TRUE;
	pixman_f_transform_multiply (f_transform, &rr_transform->f_transform, f_transform);
	pixman_f_transform_multiply (f_inverse, f_inverse, &rr_transform->f_inverse);
    }
#endif
    /*
     * Compute the class of the resulting transform
     */
    if (!overflow && pixman_transform_is_identity (transform))
    {
	pixman_transform_init_translate (transform, F ( x), F ( y));

	pixman_f_transform_init_translate (f_transform,  x,  y);
	pixman_f_transform_init_translate (f_inverse,   -x, -y);
	return FALSE;
    }
    else
    {
	pixman_f_transform_translate (f_transform, f_inverse, x, y);
	if (!pixman_transform_translate (transform, &inverse, F(x), F(y)))
	    overflow = TRUE;
	if (overflow)
	{
	    struct pixman_f_transform f_scaled;
	    f_scaled = *f_transform;
	    RRTransformRescale(&f_scaled, 16384.0);
	    pixman_transform_from_pixman_f_transform(transform, &f_scaled);
	}
	return TRUE;
    }
}