xref: /xsrc/external/mit/xf86-video-intel/dist/src/sna/sna_transform.c

/*
 * Copyright 1998-1999 Precision Insight, Inc., Cedar Park, Texas.  All Rights Reserved.
 * Copyright (c) 2005 Jesse Barnes <jbarnes@virtuousgeek.org>
 * Copyright © 2010 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Authors:
 *    Jesse Barns <jbarnes@virtuousgeek.org>
 *    Chris Wilson <chris@chris-wilson.co.uk>
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "sna.h"

/**
 * Returns whether the provided transform is affine.
 *
 * transform may be null.
 */
bool sna_transform_is_affine(const PictTransform *t)
{
	if (t == NULL)
		return true;

	return t->matrix[2][0] == 0 && t->matrix[2][1] == 0;
}

bool
sna_transform_is_translation(const PictTransform *t,
			     pixman_fixed_t *tx,
			     pixman_fixed_t *ty)
{
	if (t == NULL) {
		*tx = *ty = 0;
		return true;
	}

	if (t->matrix[0][0] != IntToxFixed(1) ||
	    t->matrix[0][1] != 0 ||
	    t->matrix[1][0] != 0 ||
	    t->matrix[1][1] != IntToxFixed(1) ||
	    t->matrix[2][0] != 0 ||
	    t->matrix[2][1] != 0 ||
	    t->matrix[2][2] != IntToxFixed(1))
		return false;

	*tx = t->matrix[0][2];
	*ty = t->matrix[1][2];
	return true;
}

bool
sna_transform_is_integer_translation(const PictTransform *t, int16_t *tx, int16_t *ty)
{
	if (t == NULL) {
		*tx = *ty = 0;
		return true;
	}

	if (t->matrix[0][0] != IntToxFixed(1) ||
	    t->matrix[0][1] != 0 ||
	    t->matrix[1][0] != 0 ||
	    t->matrix[1][1] != IntToxFixed(1) ||
	    t->matrix[2][0] != 0 ||
	    t->matrix[2][1] != 0 ||
	    t->matrix[2][2] != IntToxFixed(1))
		return false;

	if (pixman_fixed_fraction(t->matrix[0][2]) ||
	    pixman_fixed_fraction(t->matrix[1][2]))
		return false;

	*tx = pixman_fixed_to_int(t->matrix[0][2]);
	*ty = pixman_fixed_to_int(t->matrix[1][2]);
	return true;
}

bool
sna_transform_is_imprecise_integer_translation(const PictTransform *t,
					       int filter, bool precise,
					       int16_t *tx, int16_t *ty)
{
	if (t == NULL) {
		DBG(("%s: no transform\n", __FUNCTION__));
		*tx = *ty = 0;
		return true;
	}

	DBG(("%s: FilterNearest?=%d, precise?=%d, transform=[%f %f %f, %f %f %f, %f %f %f]\n",
	     __FUNCTION__, filter==PictFilterNearest, precise,
	     t->matrix[0][0]/65536., t->matrix[0][1]/65536., t->matrix[0][2]/65536.,
	     t->matrix[1][0]/65536., t->matrix[1][1]/65536., t->matrix[1][2]/65536.,
	     t->matrix[2][0]/65536., t->matrix[2][1]/65536., t->matrix[2][2]/65536.));

	if (t->matrix[0][0] != IntToxFixed(1) ||
	    t->matrix[0][1] != 0 ||
	    t->matrix[1][0] != 0 ||
	    t->matrix[1][1] != IntToxFixed(1) ||
	    t->matrix[2][0] != 0 ||
	    t->matrix[2][1] != 0 ||
	    t->matrix[2][2] != IntToxFixed(1)) {
		DBG(("%s: not unity scaling\n", __FUNCTION__));
		return false;
	}

	if (filter != PictFilterNearest) {
		if (precise) {
			if (pixman_fixed_fraction(t->matrix[0][2]) ||
			    pixman_fixed_fraction(t->matrix[1][2])) {
				DBG(("%s: precise, fractional translation\n", __FUNCTION__));
				return false;
			}
		} else {
			int f;

			f = pixman_fixed_fraction(t->matrix[0][2]);
			if (f > IntToxFixed(1)/4 && f < IntToxFixed(3)/4) {
				DBG(("%s: imprecise, fractional translation X: %x\n", __FUNCTION__, f));
				return false;
			}

			f = pixman_fixed_fraction(t->matrix[1][2]);
			if (f > IntToxFixed(1)/4 && f < IntToxFixed(3)/4) {
				DBG(("%s: imprecise, fractional translation Y: %x\n", __FUNCTION__, f));
				return false;
			}
		}
	}

	*tx = pixman_fixed_to_int(t->matrix[0][2] + IntToxFixed(1)/2);
	*ty = pixman_fixed_to_int(t->matrix[1][2] + IntToxFixed(1)/2);
	return true;
}

/**
 * Returns the floating-point coordinates transformed by the given transform.
 */
void
sna_get_transformed_coordinates(int x, int y,
			       	const PictTransform *transform,
				float *x_out, float *y_out)
{
	if (transform == NULL) {
		*x_out = x;
		*y_out = y;
	} else
		_sna_get_transformed_coordinates(x, y, transform, x_out, y_out);
}

/**
 * Returns the un-normalized floating-point coordinates transformed by the given transform.
 */
void
sna_get_transformed_coordinates_3d(int x, int y,
				   const PictTransform *transform,
				   float *x_out, float *y_out, float *w_out)
{
	if (transform == NULL) {
		*x_out = x;
		*y_out = y;
		*w_out = 1;
	} else {
		int64_t result[3];

		if (_sna_transform_point(transform, x, y, result)) {
			*x_out = result[0] / 65536.;
			*y_out = result[1] / 65536.;
			*w_out = result[2] / 65536.;
		} else {
			*x_out = *y_out = 0;
			*w_out = 1.;
		}
	}
}