ui_rect_util.h File Reference

Utility functions to handle rectangles. More...

#include <stddef.h>
#include "ui_rect.h"
#include "ui_util.h"

Go to the source code of this file.

Macros
#define	UI_RECT_EMPTY   { 1u, 1u, 0u, 0u }
	The initializer of an empty rectangle: its end (x2,y2) is before its start (x1,y1).

Functions
ui_rect_t	UI_RECT_get_minimum_bounding_rect (const ui_rect_t rects[], const size_t count)
	Computes the minimum bounding rectangle of an array of rectangles. More...
uint32_t	UI_RECT_union (ui_rect_t output[3], const ui_rect_t *first, const ui_rect_t *second)
	Computes the union of two rectangles. More...
uint32_t	UI_RECT_subtract (ui_rect_t output[4], const ui_rect_t *first, const ui_rect_t *second)
	Computes the difference between two rectangles. More...

Detailed Description

Utility functions to handle rectangles.

See also

ui_rect_t

Author

MicroEJ Developer Team

Version

14.5.5

Definition in file ui_rect_util.h.

Function Documentation

UI_RECT_get_minimum_bounding_rect()

ui_rect_t UI_RECT_get_minimum_bounding_rect	(	const ui_rect_t	rects[],
		const size_t	count
	)

Computes the minimum bounding rectangle of an array of rectangles.

The behavior is undefined if the array is empty.

Parameters

[in]	rects	the array of rectangles
[in]	count	the length of the array

Returns

the minimum bounding rectangle

Definition at line 32 of file ui_rect_util.c.

                                                                                         {
    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;
}

UI_RECT_subtract()

uint32_t UI_RECT_subtract	(	ui_rect_t	output[4],
		const ui_rect_t *	first,
		const ui_rect_t *	second
	)

Computes the difference between two rectangles.

Parameters

[out]	output	the rectangles defining the difference between the parameters
[in]	first	the original rectangle
[in]	second	the rectangle that will be removed from the original one

Returns

the number of resulting rectangles. Some of them may be empty.

Definition at line 89 of file ui_rect_util.c.

                                                                                                {
    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;
}

UI_RECT_union()

uint32_t UI_RECT_union	(	ui_rect_t	output[3],
		const ui_rect_t *	first,
		const ui_rect_t *	second
	)

Computes the union of two rectangles.

Parameters

[out]	output	rectangles defining the union of the parameters
[in]	first	the first rectangle
[in]	second	the second rectangle

Returns

the number of resulting rectangles. Some of them may be empty.

Definition at line 42 of file ui_rect_util.c.

                                                                                             {
    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;
}