ui_rect_util.c

/*
 * C
 *
 * Copyright 2024-2025 MicroEJ Corp. All rights reserved.
 * MicroEJ Corp. PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
 
/*
 * @file
 * @brief Utility functions to handle rectangles
 *
 * @see ui_rect_t
 *
 * @author MicroEJ Developer Team
 * @version 14.5.5
 */
 
// --------------------------------------------------------------------------------
// Includes
// --------------------------------------------------------------------------------
 
#include <assert.h>
 
#include "ui_util.h"
#include "ui_rect_util.h"
 
// --------------------------------------------------------------------------------
// Functions
// --------------------------------------------------------------------------------
 
// See the header file for the function documentation
ui_rect_t UI_RECT_get_minimum_bounding_rect(const ui_rect_t rects[], const size_t count) {
    assert(count > 0u);
    ui_rect_t result = rects[0];
    for (size_t i = 1; i < count; i++) {
        result = UI_RECT_get_minimum_bounding_rect_two_rects(&result, &rects[i]);
    }
    return result;
}
 
// See the header file for the function documentation
uint32_t UI_RECT_union(ui_rect_t output[3], const ui_rect_t *first, const ui_rect_t *second) {
    uint32_t ret;
    if (UI_RECT_contains_rect(first, second)) {
        output[0] = *first;
        UI_RECT_mark_empty(&output[1]);
        UI_RECT_mark_empty(&output[2]);
        ret = 1u;
    } else if (UI_RECT_contains_rect(second, first)) {
        output[0] = *second;
        UI_RECT_mark_empty(&output[1]);
        UI_RECT_mark_empty(&output[2]);
        ret = 1u;
    } else if (!UI_RECT_intersects_rect(first, second)) {
        output[0] = *first;
        output[1] = *second;
        UI_RECT_mark_empty(&output[2]);
        ret = 2u;
    } else {
        const ui_rect_t *top_above = (first->y1 < second->y1) ? first : second;
        const ui_rect_t *top_below = (first->y1 < second->y1) ? second : first;
        const ui_rect_t *bottom_below = (first->y2 > second->y2) ? first : second;
        const ui_rect_t *bottom_above = (first->y2 > second->y2) ? second : first;
 
        uint32_t count = 0u;
 
        output[count] = UI_RECT_new_xyxy(top_above->x1, top_above->y1, top_above->x2, top_below->y1 - 1);
        if (!UI_RECT_is_empty(output)) {
            count++;
        }
 
        output[count] = UI_RECT_new_xyxy(MIN(first->x1, second->x1), top_below->y1, MAX(first->x2, second->x2),
                                         bottom_above->y2);
        if (!UI_RECT_is_empty(output)) {
            count++;
        }
 
        output[count] = UI_RECT_new_xyxy(bottom_below->x1, bottom_above->y2 + 1, bottom_below->x2, bottom_below->y2);
        if (!UI_RECT_is_empty(output)) {
            count++;
        }
 
        ret = count;
    }
    return ret;
}
 
// See the header file for the function documentation
uint32_t UI_RECT_subtract(ui_rect_t output[4], const ui_rect_t *first, const ui_rect_t *second) {
    uint32_t ret;
    if (UI_RECT_contains_rect(first, second)) {
        output[0] = UI_RECT_new_xyxy(first->x1, first->y1, first->x2, second->y1 - 1); // Top
        output[1] = UI_RECT_new_xyxy(first->x1, second->y1, second->x1 - 1, second->y2); // Left
        output[2] = UI_RECT_new_xyxy(second->x2 + 1, second->y1, first->x2, second->y2); // Right
        output[3] = UI_RECT_new_xyxy(first->x1, second->y2 + 1, first->x2, first->y2); // Bottom
        ret = 4u;
    } else if (UI_RECT_contains_rect(second, first)) {
        UI_RECT_mark_empty(&output[0]);
        UI_RECT_mark_empty(&output[1]);
        UI_RECT_mark_empty(&output[2]);
        UI_RECT_mark_empty(&output[3]);
        ret = 0u;
    } else if (!UI_RECT_intersects_rect(first, second)) {
        output[0] = *first;
        UI_RECT_mark_empty(&output[1]);
        UI_RECT_mark_empty(&output[2]);
        UI_RECT_mark_empty(&output[3]);
        ret = 1u;
    } else {
        output[0] = UI_RECT_new_xyxy(first->x1, first->y1, first->x2, second->y1 - 1); // Top
        output[1] = UI_RECT_new_xyxy(first->x1, MAX(first->y1, second->y1), second->x1 - 1, MIN(first->y2, second->y2)); // Left
        output[2] = UI_RECT_new_xyxy(second->x2 + 1, MAX(first->y1, second->y1), first->x2, MIN(first->y2, second->y2)); // Right
        output[3] = UI_RECT_new_xyxy(first->x1, second->y2 + 1, first->x2, first->y2); // Bottom
        ret = 4u;
    }
    return ret;
}