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wolf_dart/packages/wolf_3d_renderer/lib/ascii_rasterizer.dart
2026-03-16 01:01:45 +01:00

242 lines
7.8 KiB
Dart

import 'dart:math' as math;
import 'package:flutter/material.dart';
import 'package:wolf_3d_data_types/wolf_3d_data_types.dart';
import 'package:wolf_3d_engine/wolf_3d_engine.dart';
import 'package:wolf_3d_entities/wolf_3d_entities.dart';
class ColoredChar {
final String char;
final Color color;
ColoredChar(this.char, this.color);
}
class AsciiRasterizer {
static const String _charset = "@%#*+=-:. ";
// NEW: Helper to safely convert and artificially boost your raw memory colors
Color _vgaToColor(int vgaColor, {double brightnessBoost = 2.0}) {
int r = vgaColor & 0xFF;
int g = (vgaColor >> 8) & 0xFF;
int b = (vgaColor >> 16) & 0xFF;
// Apply the boost and clamp to 255 to prevent color overflow
r = (r * brightnessBoost).toInt().clamp(0, 255);
g = (g * brightnessBoost).toInt().clamp(0, 255);
b = (b * brightnessBoost).toInt().clamp(0, 255);
// Force Alpha to 255 (fully opaque)
return Color.fromARGB(255, r, g, b);
}
List<List<ColoredChar>> render(WolfEngine engine, FrameBuffer framebuffer) {
final int width = framebuffer.width;
final int height = framebuffer.height;
// Grab ceiling and floor colors from the original palette
final Color ceilingColor = _vgaToColor(ColorPalette.vga32Bit[25]);
final Color floorColor = _vgaToColor(ColorPalette.vga32Bit[29]);
final List<List<ColoredChar>> screen = List.generate(
height,
(_) => List.filled(width, ColoredChar(' ', ceilingColor)),
);
final List<double> zBuffer = List.filled(width, 0.0);
final Player player = engine.player;
final SpriteMap map = engine.currentLevel;
final List<Sprite> wallTextures = engine.data.walls;
final double fov = math.pi / 3;
Coordinate2D dir = Coordinate2D(
math.cos(player.angle),
math.sin(player.angle),
);
Coordinate2D plane = Coordinate2D(-dir.y, dir.x) * math.tan(fov / 2);
// 1. CAST WALLS
for (int x = 0; x < width; x++) {
double cameraX = 2 * x / width - 1.0;
Coordinate2D rayDir = dir + (plane * cameraX);
int mapX = player.x.toInt();
int mapY = player.y.toInt();
double deltaDistX = (rayDir.x == 0) ? 1e30 : (1.0 / rayDir.x).abs();
double deltaDistY = (rayDir.y == 0) ? 1e30 : (1.0 / rayDir.y).abs();
double sideDistX, sideDistY;
int stepX, stepY, side = 0, hitWallId = 0;
bool hit = false;
if (rayDir.x < 0) {
stepX = -1;
sideDistX = (player.x - mapX) * deltaDistX;
} else {
stepX = 1;
sideDistX = (mapX + 1.0 - player.x) * deltaDistX;
}
if (rayDir.y < 0) {
stepY = -1;
sideDistY = (player.y - mapY) * deltaDistY;
} else {
stepY = 1;
sideDistY = (mapY + 1.0 - player.y) * deltaDistY;
}
while (!hit) {
if (sideDistX < sideDistY) {
sideDistX += deltaDistX;
mapX += stepX;
side = 0;
} else {
sideDistY += deltaDistY;
mapY += stepY;
side = 1;
}
if (mapY < 0 ||
mapY >= map.length ||
mapX < 0 ||
mapX >= map[0].length) {
break;
}
if (map[mapY][mapX] > 0) {
hit = true;
hitWallId = map[mapY][mapX];
}
}
double perpWallDist = (side == 0)
? (sideDistX - deltaDistX)
: (sideDistY - deltaDistY);
if (perpWallDist < 0.1) perpWallDist = 0.1;
zBuffer[x] = perpWallDist;
double wallX = (side == 0)
? player.y + perpWallDist * rayDir.y
: player.x + perpWallDist * rayDir.x;
wallX -= wallX.floor();
int texX = (wallX * 64).toInt().clamp(0, 63);
int texNum = ((hitWallId - 1) * 2).clamp(0, wallTextures.length - 2);
if (side == 1) texNum += 1;
Sprite texture = wallTextures[texNum];
int columnHeight = (height / perpWallDist).toInt();
int drawStart = (-columnHeight ~/ 2 + height ~/ 2).clamp(0, height);
int drawEnd = (columnHeight ~/ 2 + height ~/ 2).clamp(0, height);
double brightness = (1.5 / (perpWallDist + 1.0)).clamp(0.0, 1.0);
String wallChar =
_charset[((1.0 - brightness) * (_charset.length - 1)).toInt().clamp(
0,
_charset.length - 1,
)];
for (int y = 0; y < height; y++) {
if (y >= drawStart && y < drawEnd) {
double relativeY = (y - drawStart) / (drawEnd - drawStart);
int texY = (relativeY * 64).toInt().clamp(0, 63);
int colorByte = texture.pixels[texX * 64 + texY];
// Use our new color conversion!
Color pixelColor = _vgaToColor(ColorPalette.vga32Bit[colorByte]);
// Optional: slightly darken the Y-side walls for a faux-lighting effect
// if (side == 1) {
// pixelColor = Color.fromARGB(
// 255,
// (pixelColor.r * 0.7).toInt(),
// (pixelColor.g * 0.7).toInt(),
// (pixelColor.b * 0.7).toInt(),
// );
// }
screen[y][x] = ColoredChar(wallChar, pixelColor);
} else if (y >= drawEnd) {
// Floor
screen[y][x] = ColoredChar('.', floorColor);
} else {
// Ceiling
screen[y][x] = ColoredChar(' ', ceilingColor);
}
}
}
// 2. CAST SPRITES (Enemies/Items)
final List<Entity> activeSprites = List.from(engine.entities);
activeSprites.sort((a, b) {
double distA = player.position.distanceTo(a.position);
double distB = player.position.distanceTo(b.position);
return distB.compareTo(distA);
});
for (Entity entity in activeSprites) {
Coordinate2D spritePos = entity.position - player.position;
double invDet = 1.0 / (plane.x * dir.y - dir.x * plane.y);
double transformX = invDet * (dir.y * spritePos.x - dir.x * spritePos.y);
double transformY =
invDet * (-plane.y * spritePos.x + plane.x * spritePos.y);
if (transformY > 0) {
int spriteScreenX = ((width / 2) * (1 + transformX / transformY))
.toInt();
int spriteHeight = (height / transformY).abs().toInt();
int spriteWidth = (spriteHeight * (width / height) * 0.6).toInt();
int drawStartY = -spriteHeight ~/ 2 + height ~/ 2;
int drawEndY = spriteHeight ~/ 2 + height ~/ 2;
int drawStartX = -spriteWidth ~/ 2 + spriteScreenX;
int drawEndX = spriteWidth ~/ 2 + spriteScreenX;
int clipStartX = math.max(0, drawStartX);
int clipEndX = math.min(width - 1, drawEndX);
int safeIndex = entity.spriteIndex.clamp(
0,
engine.data.sprites.length - 1,
);
Sprite spritePixels = engine.data.sprites[safeIndex];
double brightness = (1.5 / (transformY + 1.0)).clamp(0.0, 1.0);
String spriteChar =
_charset[((1.0 - brightness) * (_charset.length - 1)).toInt().clamp(
0,
_charset.length - 1,
)];
for (int stripe = clipStartX; stripe < clipEndX; stripe++) {
if (transformY < zBuffer[stripe]) {
int texX = ((stripe - drawStartX) * 64 ~/ spriteWidth).clamp(0, 63);
for (
int y = math.max(0, drawStartY);
y < math.min(height, drawEndY);
y++
) {
double relativeY = (y - drawStartY) / (drawEndY - drawStartY);
int texY = (relativeY * 64).toInt().clamp(0, 63);
int colorByte = spritePixels.pixels[texX * 64 + texY];
if (colorByte != 255) {
// Apply the safe color conversion here as well
Color pixelColor = _vgaToColor(
ColorPalette.vga32Bit[colorByte],
);
screen[y][stripe] = ColoredChar(spriteChar, pixelColor);
}
}
}
}
}
}
return screen;
}
}