nesemu/gui/pattern_display.c

//
// Created by william on 12/07/24.
//

#include <assert.h>
#include "pattern_display.h"

#define PATTERN_BYTES (PATTERN_SIZE * 2)

void pattern_display_init(PatternDisplay *display, SDL_Renderer *renderer, int tiles_x, int tiles_y, int display_type) {
    assert(tiles_x > 0);
    assert(tiles_y > 0);

    display->width = tiles_x;
    display->height = tiles_y;

    display->texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888, display_type,
                                         pattern_display_get_size(tiles_x),
                                         pattern_display_get_size(tiles_y));
}

void pattern_display_uninit(PatternDisplay *display) {
    SDL_DestroyTexture(display->texture);
}

void pattern_display_draw_borders(unsigned int *buffer, int win_width, int win_height) {
    assert(buffer != NULL);

    for (int x = 0; x < win_width; x++) {
        buffer[x] = PATTERN_BORDER_COLOR;
    }

    for (int y = 1; y < win_height; y++) {
        buffer[y * win_width] = PATTERN_BORDER_COLOR;
    }
}

void pattern_display_build_table(PatternTile *tile_table, int tile_count, read_func read_func,
                                 void *read_func_data) {
    for (int tile_index = 0; tile_index < tile_count; tile_index++) {
        PatternTile *tile = &tile_table[tile_index];

        address tile_addr = tile_index * PATTERN_BYTES;
        memcpy(tile->data_low, read_func(tile_addr, read_func_data), 8);
        memcpy(tile->data_high, read_func(tile_addr + 8, read_func_data), 8);
    }
}

void pattern_display_draw_tile_borders(int tile_addr, pixel *buffer, int win_width) {
    assert(buffer != NULL);

    for (int by = 0; by < PATTERN_DRAW_SIZE; by++) {
        address pixel_addr = tile_addr + (by * win_width) + PATTERN_DRAW_SIZE - 1;
        buffer[pixel_addr] = PATTERN_BORDER_COLOR;
    }

    for (int bx = 0; bx < PATTERN_DRAW_SIZE; bx++) {
        address pixel_addr = tile_addr + ((PATTERN_DRAW_SIZE - 1) * win_width) + bx;
        buffer[pixel_addr] = PATTERN_BORDER_COLOR;
    }
}

void pattern_display_draw_tile(PatternTile *tile, pixel *buffer, int tile_addr, int win_width) {
    assert(buffer != NULL);

    for (int fine_y = 0; fine_y < PATTERN_SIZE; fine_y++) {
        byte data_high = tile->data_high[fine_y];
        byte data_low = tile->data_low[fine_y];

        for (int fine_x = 0; fine_x < PATTERN_SIZE; fine_x++) {
            byte bitmask = 1 << (PATTERN_SIZE - fine_x - 1);
            byte bit_high = data_high & bitmask;
            byte bit_low = data_low & bitmask;

            int pixel_addr = tile_addr + fine_x + fine_y * win_width;
            pixel *pixel = &buffer[pixel_addr];

            // TODO: Use palette colors
            if (bit_high && bit_low) {
                *pixel = 0xffffffff;
            } else if (bit_low) {
                *pixel = 0xffff0000;
            } else if (bit_high) {
                *pixel = 0xff00ffff;
            } else {
                *pixel = 0xff000000;
            }
        }
    }

    pattern_display_draw_tile_borders(tile_addr, buffer, win_width);
}

void pattern_display_build(PatternDisplay *display, read_func read_func, void *read_func_data) {
    int tile_count = display->width * display->height;
    PatternTile *tile_table = malloc(tile_count * sizeof(PatternTile));
    pattern_display_build_table(tile_table, tile_count, read_func, read_func_data);

    int win_width = pattern_display_get_size(display->width);
    int win_height = pattern_display_get_size(display->height);
    pixel *buffer = malloc(win_width * win_height * sizeof(pixel));

    pattern_display_draw_borders(buffer, win_width, win_height);

    for (int x = 0; x < display->width; x++) {
        for (int y = 0; y < display->height; y++) {
            PatternTile *tile = &tile_table[x + y * display->width];
            address row_addr = (y * PATTERN_DRAW_SIZE + PATTERN_BORDER_WIDTH) * win_width;
            address tile_addr = row_addr + (x * PATTERN_DRAW_SIZE + PATTERN_BORDER_WIDTH);

            pattern_display_draw_tile(tile, buffer, tile_addr, win_width);
        }
    }

    SDL_UpdateTexture(display->texture, NULL, buffer, win_width * sizeof(pixel));

    free(tile_table);
    free(buffer);
}

void pattern_display_render(PatternDisplay *display, SDL_Renderer *renderer) {
    SDL_RenderCopy(renderer, display->texture, NULL, NULL);
}