circuitpython/shared-module/displayio/Shape.c

/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2019 Scott Shawcroft for Adafruit Industries
 *
 * 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 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.
 */

#include "shared-bindings/displayio/Shape.h"

#include <string.h>

#include "py/runtime.h"
#include "py/misc.h"

void common_hal_displayio_shape_construct(displayio_shape_t *self, uint32_t width,
    uint32_t height, bool mirror_x, bool mirror_y) {
    self->mirror_x = mirror_x;
    self->mirror_y = mirror_y;
    self->width = width;
    if (self->mirror_x) {
        width /= 2;
        width += self->width % 2;
    }
    self->half_width = width;

    self->height = height;
    if (self->mirror_y) {
        height /= 2;
        height += self->height % 2;
    }
    self->half_height = height;

    self->data = m_malloc(height * sizeof(uint32_t));

    for (uint16_t i = 0; i < height; i++) {
        self->data[2 * i] = 0;
        self->data[2 * i + 1] = width;
    }

    self->dirty_area.x1 = 0;
    self->dirty_area.x2 = width;
    self->dirty_area.y1 = 0;
    self->dirty_area.y2 = height;
}

void common_hal_displayio_shape_set_boundary(displayio_shape_t *self, uint16_t y, uint16_t start_x, uint16_t end_x) {
    uint16_t max_y = self->height - 1;
    if (self->mirror_y) {
        max_y = self->half_height - 1;
    }
    mp_arg_validate_int_range(y, 0, max_y, MP_QSTR_y);
    uint16_t max_x = self->width - 1;
    if (self->mirror_x) {
        max_x = self->half_width - 1;
    }
    mp_arg_validate_int_range(start_x, 0, max_x, MP_QSTR_start_x);
    mp_arg_validate_int_range(end_x, 0, max_x, MP_QSTR_end_x);

    uint16_t lower_x, upper_x, lower_y, upper_y;

    // find x-boundaries for updating based on current data and start_x, end_x, and mirror_x
    lower_x = MIN(start_x, self->data[2 * y]);

    if (self->mirror_x) {
        upper_x = self->width - lower_x + 1; // dirty rectangles are treated with max value exclusive
    } else {
        upper_x = MAX(end_x, self->data[2 * y + 1]) + 1; // dirty rectangles are treated with max value exclusive
    }

    // find y-boundaries based on y and mirror_y
    lower_y = y;

    if (self->mirror_y) {
        upper_y = self->height - lower_y + 1; // dirty rectangles are treated with max value exclusive
    } else {
        upper_y = y + 1; // dirty rectangles are treated with max value exclusive
    }

    self->data[2 * y] = start_x; // update the data array with the new boundaries
    self->data[2 * y + 1] = end_x;

    if (self->dirty_area.x1 == self->dirty_area.x2) { // Dirty region is empty
        self->dirty_area.x1 = lower_x;
        self->dirty_area.x2 = upper_x;
        self->dirty_area.y1 = lower_y;
        self->dirty_area.y2 = upper_y;

    } else { // Dirty region is not empty
        self->dirty_area.x1 = MIN(lower_x, self->dirty_area.x1);
        self->dirty_area.x2 = MAX(upper_x, self->dirty_area.x2);

        self->dirty_area.y1 = MIN(lower_y, self->dirty_area.y1);
        self->dirty_area.y2 = MAX(upper_y, self->dirty_area.y2);
    }
}

uint32_t common_hal_displayio_shape_get_pixel(void *obj, int16_t x, int16_t y) {
    displayio_shape_t *self = obj;
    if (x >= self->width || x < 0 || y >= self->height || y < 0) {
        return 0;
    }
    if (self->mirror_x && x >= self->half_width) {
        x = self->width - x - 1;
    }
    if (self->mirror_y && y >= self->half_height) {
        y = self->height - y - 1;
    }
    uint16_t start_x = self->data[2 * y];
    uint16_t end_x = self->data[2 * y + 1];
    if (x < start_x || x > end_x) {
        return 0;
    }
    return 1;
}

displayio_area_t *displayio_shape_get_refresh_areas(displayio_shape_t *self, displayio_area_t *tail) {
    if (self->dirty_area.x1 == self->dirty_area.x2) {
        return tail;
    }
    self->dirty_area.next = tail;
    return &self->dirty_area;
}

void displayio_shape_finish_refresh(displayio_shape_t *self) {
    self->dirty_area.x1 = 0;
    self->dirty_area.x2 = 0;
}