#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_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 &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); } } } }