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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2017 Radomir Dopieralski
*
* 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 "Layer.h"
#include "__init__.h"
// Get the color of the pixel on the layer.
uint16_t get_layer_pixel(layer_obj_t *layer, int16_t x, int16_t y) {
// Shift by the layer's position offset.
x -= layer->x;
y -= layer->y;
// Bounds check.
if ((x < 0) || (x >= layer->width << 4) ||
(y < 0) || (y >= layer->height << 4)) {
return TRANSPARENT;
}
// Get the tile from the grid location or from sprite frame.
uint8_t frame = layer->frame;
if (layer->map) {
uint8_t tx = x >> 4;
uint8_t ty = y >> 4;
frame = layer->map[(ty * layer->width + tx) >> 1];
if (tx & 0x01) {
frame &= 0x0f;
} else {
frame >>= 4;
}
}
// Get the position within the tile.
x &= 0x0f;
y &= 0x0f;
// Rotate the image.
uint8_t ty = y; // Temporary variable for swapping.
switch (layer->rotation) {
case 1: // 90 degrees clockwise
y = 15 - x;
x = ty;
break;
case 2: // 180 degrees
y = 15 - ty;
x = 15 - x;
break;
case 3: // 90 degrees counter-clockwise
y = x;
x = 15 - ty;
break;
case 4: // 0 degrees, mirrored
x = 15 - x;
break;
case 5: // 90 degrees clockwise, mirrored
y = x;
x = ty;
break;
case 6: // 180 degrees, mirrored
y = 15 - ty;
break;
case 7: // 90 degrees counter-clockwise, mirrored
y = 15 - x;
x = 15 - ty;
break;
default: // 0 degrees
break;
}
// Get the value of the pixel.
uint8_t pixel = layer->graphic[(frame << 7) + (y << 3) + (x >> 1)];
if (x & 0x01) {
pixel &= 0x0f;
} else {
pixel >>= 4;
}
// Convert to 16-bit color using the palette.
return layer->palette[pixel << 1] | layer->palette[(pixel << 1) + 1] << 8;
}
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