render.hh

// (C) 2026 Lumisetiq

#ifndef RENDER_HH
#define RENDER_HH

#include <cmath>

class Renderer {
public:
  uint8_t canvas[8][8];

  Renderer() {
    clearFrame();
  }

  void clearFrame() {
    memset(canvas, 0, sizeof(canvas));
  }

  void setPixel(int x, int y, bool on) {
    if (x < 0 || x >= 20 || y < 0 || y >= 16) return;
    uint8_t charIdx = (x / 5) + (y / 8) * 4;
    uint8_t rowIdx = y % 8;
    uint8_t bitIdx = 4 - (x % 5);
    if (on) canvas[charIdx][rowIdx] |= (1 << bitIdx);
    else canvas[charIdx][rowIdx] &= ~(1 << bitIdx);
  }

  void drawLine(int x0, int y0, int x1, int y1) {
    int dx = abs(x1 - x0), sx = x0 < x1 ? 1 : -1;
    int dy = -abs(y1 - y0), sy = y0 < y1 ? 1 : -1;
    int err = dx + dy, e2;
    while (true) {
      setPixel(x0, y0, true);
      if (x0 == x1 && y0 == y1) break;
      e2 = 2 * err;
      if (e2 >= dy) { err += dy; x0 += sx; }
      if (e2 <= dx) { err += dx; y0 += sy; }
    }
  }

  void renderCompass(float degrees) {
    clearFrame();
    int cx = 10, cy = 7, r = 7;
    float rad = (degrees - 90.0f) * M_PI / 180.0f;
    int tx = cx + (int)(cos(rad) * r);
    int ty = cy + (int)(sin(rad) * r);
    
    setPixel(10, 0, true);
    setPixel(10, 15, true);
    setPixel(0, 7, true);
    setPixel(19, 7, true);
    
    drawLine(cx, cy, tx, ty);
  }
};

#endif