atmega-geiger/src/framebuffer.c

//
// Created by MightyPork on 2022/11/12.
//

#include "user_interface.h"
#include "framebuffer.h"
#include "ssd1306.h"

/* Tiny framebuffer */
#define FBW DISPLAY_W
#define FBH DISPLAY_H

#define MIN(a,b) ((a)>(b)?(b):(a))
#define MAX(a,b) ((a)>(b)?(a):(b))

static uint8_t fb[(FBH/8)*FBW];

/** Fill with a vertical pattern, 1 byte */
void fb_fill(uint8_t pattern) {
    memset(fb, pattern, sizeof(fb));
}

void fb_clear() {
    fb_fill(0);
}

void fb_px(uint8_t x, uint8_t y, uint8_t color) {
    if (x >= FBW || y >= FBH) return;
    const uint8_t row = y / 8;
    const uint8_t rowrem = y % 8;
    const uint16_t cell = (uint16_t) x + (uint16_t) row * FBW;
    if (color) {
        fb[cell] |= (1 << rowrem);
    } else {
        fb[cell] &= ~(1 << rowrem);
    }
}

void fb_hline(uint8_t x, uint8_t y, uint8_t w, uint8_t color) {
    if (x >= FBW || y >= FBH) return;
    w = MIN(FBW - x, w);
    const uint8_t row = y / 8;
    const uint8_t rowrem = y % 8;
    uint16_t cell = (uint16_t) x + (uint16_t) row * FBW;
    for(uint8_t i = 0; i < w; i++) {
        if (color) {
            fb[cell] |= (1 << rowrem);
        } else {
            fb[cell] &= ~(1 << rowrem);
        }
        cell++;
    }
}

void fb_vline(uint8_t x, uint8_t y, uint8_t h, uint8_t color) {
    if (x >= FBW || y >= FBH) return;
    h = MIN(FBH - y - 1, h);
    const uint8_t row = y / 8;
    const uint8_t rowrem = y % 8;
    uint16_t cell = (uint16_t) x + (uint16_t) row * FBW;

    if (rowrem + h < 8) {
        // all within one cell
        uint8_t mask = (0xFF << rowrem) & (0xFF >> (h-rowrem));
        if (color) {
            fb[cell] |= mask;
        } else {
            fb[cell] &= ~mask;
        }
        return;
    } else {
        // First
        uint8_t mask = (0xFF << rowrem);
        if (color) {
            fb[cell] |= mask;
        } else {
            fb[cell] &= ~mask;
        }
        h -= rowrem;

        uint8_t whole_cells = h / 8;
        h -= whole_cells * 8;
        for(uint8_t i = 0; i < whole_cells; i++) {
            cell += FBW;
            if (color) {
                fb[cell] = 0xFF;
            } else {
                fb[cell] = 0;
            }
        }

        // last
        mask = (0xFF >> (8-h));
        if (color) {
            fb[cell] |= mask;
        } else {
            fb[cell] &= ~mask;
        }
    }
}

void fb_rect(uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t color) {
    if (x >= FBW || y >= FBH) return;
    w = MIN(FBW - x - 1, w);
    h = MIN(FBH - y - 1, h);
    const uint8_t row = y / 8;
    const uint8_t rowrem = y % 8;
    uint16_t cell = (uint16_t) x + (uint16_t) row * FBW;

    if (rowrem + h <= 8) {
        // all within one cell
        uint8_t mask = (0xFF << rowrem) & (0xFF >> (8 - (h - rowrem)));

        for(uint8_t i = 0; i < w; i++) {
            if (color) {
                fb[cell + i] |= mask;
            } else {
                fb[cell + i] &= ~mask;
            }
        }
        return;
    } else {
        // First
        uint8_t mask = (0xFF << rowrem);
        for(uint8_t i = 0; i < w; i++) {
            if (color) {
                fb[cell + i] |= mask;
            } else {
                fb[cell + i] &= ~mask;
            }
        }
        h -= 8 - rowrem;

        uint8_t whole_cells = h / 8;
        h -= whole_cells * 8;
        for(uint8_t j = 0; j < whole_cells; j++) {
            cell += FBW;
            for(uint8_t i = 0; i < w; i++) {
                if (color) {
                    fb[cell + i] = 0xFF;
                } else {
                    fb[cell + i] = 0;
                }
            }
        }

        cell += FBW;

        // last
        mask = (0xFF >> (8-h));
        for(uint8_t i = 0; i < w; i++) {
            if (color) {
                fb[cell + i] |= mask;
            } else {
                fb[cell + i] &= ~mask;
            }
        }
    }
}

void fb_bitmap(uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *map, uint8_t color) {
    if (x >= FBW || y >= FBH) return;
    const uint8_t w0 = w;
    const uint8_t h0 = h;
    w = MIN(FBW - x - 1, w);
    h = MIN(FBH - y - 1, h);
    const uint8_t row = y / 8;
    const uint8_t rowrem = y % 8;
    uint16_t cell = (uint16_t) x + (uint16_t) row * FBW;

    if (rowrem + h <= 8) {
        for(uint8_t i = 0; i < w; i++) {
            // all within one cell
            uint8_t mask = (map[i] & (0xFF >> (8-h))) << rowrem;
            if (color) {
                fb[cell + i] |= mask;
            } else {
                fb[cell + i] &= ~mask;
            }
        }
        return;
    } else if (rowrem == 0) {
        // Optimization
        uint8_t mapc0 = 0;

        // First
        for(uint8_t i = 0; i < w; i++) {
            uint8_t mask = map[i];
            if (color) {
                fb[cell + i] |= mask;
            } else {
                fb[cell + i] &= ~mask;
            }
        }
        h -= 8;

        // Middle
        uint8_t whole_cells = h / 8;
        h -= whole_cells * 8;
        for(uint8_t j = 0; j < whole_cells; j++) {
            cell += FBW;
            mapc0 += w0;
            for(uint8_t i = 0; i < w; i++) {
                uint8_t mask = map[i + mapc0];
                if (color) {
                    fb[cell + i] |= mask;
                } else {
                    fb[cell + i] &= ~mask;
                }
            }
        }

        // last
        mapc0 += w0;
        cell += FBW;

        // last
        for(uint8_t i = 0; i < w; i++) {
            uint8_t mask = map[i + mapc0] & (0xFF >> (8-h));
            if (color) {
                fb[cell + i] |= mask;
            } else {
                fb[cell + i] &= ~mask;
            }
        }

    } else {
        uint8_t mapc0 = 0;

        while (h > 0) {
            // First
            for (uint8_t i = 0; i < w; i++) {
                uint8_t mask = (map[i + mapc0] & (0xFF >> (rowrem))) << rowrem;
                if (color) {
                    fb[cell + i] |= mask;
                } else {
                    fb[cell + i] &= ~mask;
                }
            }

            //mapc0 += w0;
            cell += FBW;

            // leftover of the first row in map

            // last
            for (uint8_t i = 0; i < w; i++) {
                uint8_t mask = map[i + mapc0] >> (8 - rowrem);
                if (color) {
                    fb[cell + i] |= mask;
                } else {
                    fb[cell + i] &= ~mask;
                }
            }

            if (h > 8) {
                h -= 8;
            } else {
                break;
            }
            mapc0 += w0;
        }

#if 0
        // Middle
        uint8_t whole_cells = h / 8;
        h -= whole_cells * 8;
        for(uint8_t j = 0; j < whole_cells; j++) {
            cell += FBW;
            mapc0 += w0;
            for(uint8_t i = 0; i < w; i++) {
                uint8_t mask = map[i + mapc0];
                if (color) {
                    fb[cell + i] |= mask;
                } else {
                    fb[cell + i] &= ~mask;
                }
            }
        }

        // last
        mapc0 += w0;
        cell += FBW;

        // last
        for(uint8_t i = 0; i < w; i++) {
            uint8_t mask = map[i + mapc0] & (0xFF >> (8-h));
            if (color) {
                fb[cell + i] |= mask;
            } else {
                fb[cell + i] &= ~mask;
            }
        }
#endif
    }
}


void fb_blit() {
    ssd1306_drawBuffer(0, 0, FBW, FBH, fb);
}