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Text.c
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47 lines (38 loc) · 1.21 KB
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// This file is part of the CircuitPython project: https://circuitpython.org
//
// SPDX-FileCopyrightText: Copyright (c) 2017 Radomir Dopieralski
//
// SPDX-License-Identifier: MIT
#include "Text.h"
#include "__init__.h"
// Get the color of the pixel on the text.
uint16_t get_text_pixel(text_obj_t *text, int16_t x, int16_t y) {
// Shift by the text's position offset.
x -= text->x;
y -= text->y;
// Bounds check.
if ((x < 0) || (x >= text->width << 3) ||
(y < 0) || (y >= text->height << 3)) {
return TRANSPARENT;
}
// Get the tile from the grid location or from sprite frame.
uint8_t tx = x >> 3;
uint8_t ty = y >> 3;
uint8_t c = text->chars[ty * text->width + tx];
uint8_t color_offset = 0;
if (c & 0x80) {
color_offset = 4;
}
c &= 0x7f;
if (!c) {
return TRANSPARENT;
}
// Get the position within the char.
x &= 0x07;
y &= 0x07;
// Get the value of the pixel.
uint8_t pixel = text->font[(c << 4) + (y << 1) + (x >> 2)];
pixel = ((pixel >> ((x & 0x03) << 1)) & 0x03) + color_offset;
// Convert to 16-bit color using the palette.
return text->palette[pixel << 1] | text->palette[(pixel << 1) + 1] << 8;
}