source: mainline/uspace/lib/draw/source.c@ a35b458

/*
 * Copyright (c) 2012 Petr Koupy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup draw
 * @{
 */
/**
 * @file
 */

#include <assert.h>

#include "source.h"

void source_init(source_t *source)
{
        transform_identity(&source->transform);
        source->filter = filter_nearest;

        source->color = PIXEL(0, 0, 0, 0);
        source->texture = NULL;
        source->texture_extend = PIXELMAP_EXTEND_TRANSPARENT_BLACK;

        source->alpha = PIXEL(255, 0, 0, 0);
        source->mask = NULL;
        source->mask_extend = PIXELMAP_EXTEND_TRANSPARENT_BLACK;
}

void source_set_transform(source_t *source, transform_t transform)
{
        source->transform = transform;
        transform_invert(&source->transform);
}

void source_reset_transform(source_t *source)
{
        transform_identity(&source->transform);
}

void source_set_filter(source_t *source, filter_t filter)
{
        source->filter = filter;
}

void source_set_color(source_t *source, pixel_t color)
{
        source->color = color;
}

void source_set_texture(source_t *source, surface_t *texture,
    pixelmap_extend_t extend)
{
        source->texture = texture;
        source->texture_extend = extend;
}

void source_set_alpha(source_t *source, pixel_t alpha)
{
        source->alpha = alpha;
}

void source_set_mask(source_t *source, surface_t *mask,
    pixelmap_extend_t extend)
{
        source->mask = mask;
        source->mask_extend = extend;
}

bool source_is_fast(source_t *source)
{
        return ((source->mask == NULL) &&
            (source->alpha == (pixel_t) PIXEL(255, 0, 0, 0)) &&
            (source->texture != NULL) &&
            (transform_is_fast(&source->transform)));
}

pixel_t *source_direct_access(source_t *source, double x, double y)
{
        assert(source_is_fast(source));

        long _x = (long) (x + source->transform.matrix[0][2]);
        long _y = (long) (y + source->transform.matrix[1][2]);

        return pixelmap_pixel_at(
            surface_pixmap_access(source->texture), (sysarg_t) _x, (sysarg_t) _y);
}

pixel_t source_determine_pixel(source_t *source, double x, double y)
{
        if (source->mask || source->texture) {
                transform_apply_affine(&source->transform, &x, &y);
        }

        pixel_t mask_pix;
        if (source->mask) {
                mask_pix = source->filter(
                    surface_pixmap_access(source->mask),
                    x, y, source->mask_extend);
        } else {
                mask_pix = source->alpha;
        }

        if (!ALPHA(mask_pix)) {
                return 0;
        }

        pixel_t texture_pix;
        if (source->texture) {
                texture_pix = source->filter(
                    surface_pixmap_access(source->texture),
                    x, y, source->texture_extend);
        } else {
                texture_pix = source->color;
        }

        if (ALPHA(mask_pix) < 255) {
                double ratio = ((double) ALPHA(mask_pix)) / 255.0;
                double res_a = ratio * ((double) ALPHA(texture_pix));
                return PIXEL((unsigned) res_a,
                    RED(texture_pix), GREEN(texture_pix), BLUE(texture_pix));
        } else {
                return texture_pix;
        }
}

/** @}
 */