pimoroni-pico/libraries/pico_graphics/pico_graphics_pen_3bit.cpp

139 lines
5.0 KiB
C++

#include "pico_graphics.hpp"
namespace pimoroni {
PicoGraphics_Pen3Bit::PicoGraphics_Pen3Bit(uint16_t width, uint16_t height, void *frame_buffer)
: PicoGraphics(width, height, frame_buffer) {
this->pen_type = PEN_3BIT;
if(this->frame_buffer == nullptr) {
this->frame_buffer = (void *)(new uint8_t[buffer_size(width, height)]);
}
cache_built = false;
}
void PicoGraphics_Pen3Bit::_set_pixel(const Point &p, uint col) {
uint offset = (bounds.w * bounds.h) / 8;
uint8_t *buf = (uint8_t *)frame_buffer;
uint bo = 7 - (p.x & 0b111);
uint8_t *bufA = &buf[(p.x / 8) + (p.y * bounds.w / 8)];
uint8_t *bufB = bufA + offset;
uint8_t *bufC = bufA + offset + offset;
uint8_t cA = (col & 0b100) >> 2;
*bufA &= ~(1U << bo);
*bufA |= (cA << bo);
uint8_t cB = (col & 0b010) >> 1;
*bufB &= ~(1U << bo);
*bufB |= (cB << bo);
uint8_t cC = (col & 0b001);
*bufC &= ~(1U << bo);
*bufC |= (cC << bo);
}
void PicoGraphics_Pen3Bit::set_pen(uint c) {
color = c;
}
void PicoGraphics_Pen3Bit::set_pen(uint8_t r, uint8_t g, uint8_t b) {
color = RGB(r, g, b).to_rgb888() | 0x7f000000;
}
int PicoGraphics_Pen3Bit::create_pen(uint8_t r, uint8_t g, uint8_t b) {
return RGB(r, g, b).to_rgb888() | 0x7f000000;
}
int PicoGraphics_Pen3Bit::create_pen_hsv(float h, float s, float v) {
return RGB::from_hsv(h, s, v).to_rgb888() | 0x7f000000;
}
void PicoGraphics_Pen3Bit::set_thickness(uint t) {
thickness = t;
}
void PicoGraphics_Pen3Bit::set_pixel(const Point &p) {
if ((color & 0x7f000000) == 0x7f000000) {
set_pixel_dither(p, RGB(color));
} else {
_set_pixel(p, color);
}
}
void PicoGraphics_Pen3Bit::set_pixel_span(const Point &p, uint l) {
Point lp = p;
while(l--) {
if ((color & 0x7f000000) == 0x7f000000) {
set_pixel_dither(lp, RGB(color));
} else {
_set_pixel(lp, color);
}
lp.x++;
}
}
void PicoGraphics_Pen3Bit::get_dither_candidates(const RGB &col, const RGB *palette, size_t len, std::array<uint8_t, 16> &candidates) {
RGB error;
for(size_t i = 0; i < candidates.size(); i++) {
candidates[i] = (col + error).closest(palette, len);
error += (col - palette[candidates[i]]);
}
// sort by a rough approximation of luminance, this ensures that neighbouring
// pixels in the dither matrix are at extreme opposites of luminence
// giving a more balanced output
std::sort(candidates.begin(), candidates.end(), [palette](int a, int b) {
return palette[a].luminance() > palette[b].luminance();
});
}
void PicoGraphics_Pen3Bit::set_pixel_dither(const Point &p, const RGB &c) {
if(!bounds.contains(p)) return;
if(!cache_built) {
for(uint i = 0; i < 512; i++) {
uint r = (i & 0x1c0) >> 1;
uint g = (i & 0x38) << 2;
uint b = (i & 0x7) << 5;
RGB cache_col(
r | (r >> 3) | (r >> 6),
g | (g >> 3) | (g >> 6),
b | (b >> 3) | (b >> 6)
);
get_dither_candidates(cache_col, palette, palette_size, candidate_cache[i]);
}
cache_built = true;
}
uint cache_key = ((c.r & 0xE0) << 1) | ((c.g & 0xE0) >> 2) | ((c.b & 0xE0) >> 5);
//get_dither_candidates(c, palette, 256, candidates);
// find the pattern coordinate offset
uint pattern_index = (p.x & 0b11) | ((p.y & 0b11) << 2);
// set the pixel
//color = candidates[pattern[pattern_index]];
_set_pixel(p, candidate_cache[cache_key][dither16_pattern[pattern_index]]);
}
void PicoGraphics_Pen3Bit::frame_convert(PenType type, conversion_callback_func callback) {
if(type == PEN_P4) {
uint8_t row_buf[bounds.w / 2];
uint offset = (bounds.w * bounds.h) / 8;
uint8_t *buf = (uint8_t *)frame_buffer;
for(auto y = 0; y < bounds.h; y++) {
for(auto x = 0; x < bounds.w; x++) {
uint bo = 7 - (x & 0b111);
uint8_t *bufA = &buf[(x / 8) + (y * bounds.w / 8)];
uint8_t *bufB = bufA + offset;
uint8_t *bufC = bufA + offset + offset;
uint8_t nibble = (*bufA >> bo) & 1U;
nibble <<= 1;
nibble |= (*bufB >> bo) & 1U;
nibble <<= 1;
nibble |= (*bufC >> bo) & 1U;
nibble <<= (x & 0b1) ? 0 : 4;
row_buf[x / 2] &= (x & 0b1) ? 0b11110000 : 0b00001111;
row_buf[x / 2] |= nibble;
}
callback(row_buf, bounds.w / 2);
}
}
}
}