public void Render()
{
float ceilingHeight = 2f, floorHeight = 2f;
double[] zBuffer = new double[Program.ScreenWidth];
for (int x = 0; x < Program.ScreenWidth; x += detailLevel)
{
double cameraX = 2 * x / (double)Program.ScreenWidth - 1;
double rayPosX = Position.X, rayPosY = Position.Y;
double rayDirX = dirX + planeX * cameraX,
rayDirY = dirY + planeY * cameraX;
int mapX = (int)rayPosX, mapY = (int)rayPosY;
double sideDistX, sideDistY;
double deltaDistX = Math.Sqrt(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX)), deltaDistY = Math.Sqrt(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY));
int stepX, stepY;
byte side = 0;
bool hit = false;
if (rayDirX < 0)
{
stepX = -1; sideDistX = (rayPosX - mapX) * deltaDistX;
}
else
{
stepX = 1; sideDistX = (mapX + 1.0 - rayPosX) * deltaDistX;
}
if (rayDirY < 0)
{
stepY = -1; sideDistY = (rayPosY - mapY) * deltaDistY;
}
else
{
stepY = 1; sideDistY = (mapY + 1.0 - rayPosY) * deltaDistY;
}
while (!hit)
{
if (sideDistX < sideDistY)
{
sideDistX += deltaDistX; mapX += stepX; side = 0;
}
else
{
sideDistY += deltaDistY; mapY += stepY; side = 1;
}
if (WorldMap[mapX, mapY] != ' ')
{
hit = true;
}
}
double wallDist = 0;
if (side == 0)
{
wallDist = Math.Abs((mapX - rayPosX + (1 - stepX) / 2) / rayDirX);
}
else
{
wallDist = Math.Abs((mapY - rayPosY + (1 - stepY) / 2) / rayDirY);
}
zBuffer[x] = wallDist;
int lineHeight = 1;
if (wallDist != 0)
{
lineHeight = Math.Abs((int)((Program.ScreenHeight - 72) / wallDist));
}
int drawStart = -(int)((float)lineHeight / ceilingHeight) + (Program.ScreenHeight - 72) / 2;
if (drawStart < 0)
{
drawStart = 0;
}
int drawEnd = (int)((float)lineHeight / floorHeight) + (Program.ScreenHeight - 72) / 2;
if (drawEnd >= (Program.ScreenHeight - 72))
{
drawEnd = (Program.ScreenHeight - 72) - 1;
}
int textureIndex = 0;
if (char.IsNumber(WorldMap[mapX, mapY]))
{
textureIndex = int.Parse(WorldMap[mapX, mapY].ToString());
}
double wallX;
if (side == 1)
{
wallX = rayPosX + ((mapY - rayPosY + (1 - stepY) / 2) / rayDirY) * rayDirX;
}
else
{
wallX = rayPosY + ((mapX - rayPosX + (1 - stepX) / 2) / rayDirX) * rayDirY;
}
wallX -= Math.Floor((wallX));
int texX = (int)(wallX * (double)(texWidth));
if (side == 0 && rayDirX > 0)
{
texX = texWidth - texX - 1;
}
if (side == 1 && rayDirY < 0)
{
texX = texWidth - texX - 1;
}
for (int y = drawStart; y < drawEnd; y += detailLevel)
{
int d = y * 256 - (Program.ScreenHeight - 72) * 128 + lineHeight * 128;
int texY = ((d * texHeight) / lineHeight) / 256;
if (texX < 0)
{
texX = 0;
}
if (texY < 0)
{
texY = 0;
}
UInt32 color = wallTextures[textureIndex].Pixels[wallTextures[textureIndex].Width - 1 - texX, texY];
if (side == 1)
{
color = (color >> 1) & 8355711;
}
for (int u = 0; u < detailLevel; u++)
{
for (int j = 0; j < detailLevel; j++)
{
ScreenBuffer.SetPixel(x + u, y + j, color);
}
}
}
}
int h = (Program.ScreenHeight - 72), w = Program.ScreenWidth;
List <int> sortedList = SortSprites();
for (int i = sortedList.Count - 1; i >= 0; i--)
{
if (!ActorList[sortedList[i]].Remove)
{
double spriteX = ActorList[sortedList[i]].Position.X - Position.X, spriteY = ActorList[sortedList[i]].Position.Y - Position.Y;
double invDet = 1.0 / (planeX * dirY - dirX * planeY);
double transformX = invDet * (dirY * spriteX - dirX * spriteY);
double transformY = invDet * (-planeY * spriteX + planeX * spriteY);
if (transformY > 0)
{
int screenOffset = (int)(ActorList[sortedList[i]].letsPrentendThisIsZ / transformY);
int spriteScreenX = (int)((Program.ScreenWidth / 2) * (1 + transformX / transformY));
int spriteHeight = Math.Abs((int)((h / transformY))) / ActorList[sortedList[i]].Scale;
int drawStartY = (-spriteHeight / 2 + h / 2) + screenOffset;
if (drawStartY < 0)
{
drawStartY = 0;
}
int drawEndY = spriteHeight / 2 + h / 2 + screenOffset;
if (drawEndY >= h)
{
drawEndY = h - 1;
}
int spriteWidth = Math.Abs((int)(h / (transformY))) / ActorList[sortedList[i]].Scale;
int drawStartX = (-spriteWidth / 2 + spriteScreenX);
if (drawStartX < 0)
{
drawStartX = 0;
}
int drawEndX = spriteWidth / 2 + spriteScreenX;
if (drawEndX >= w)
{
drawEndX = w - 1;
}
for (int stripe = drawStartX; stripe < drawEndX; stripe++)
{
int texX = (int)(256 * (stripe - (-spriteWidth / 2 + spriteScreenX)) * texWidth / spriteWidth) / 256;
if (transformY > 0 && stripe > 0 && stripe < w && transformY < zBuffer[stripe])
{
for (int y = drawStartY; y < drawEndY; ++y)
{
int d = (y - screenOffset) * 256 - h * 128 + spriteHeight * 128;
int texY = ((d * texHeight) / spriteHeight) / 256;
uint color = ActorList[sortedList[i]].Sprite.Texture.Pixels[Math.Abs(texX), Math.Abs(texY)];
if (color != 4294967295)
{
for (int u = 0; u < detailLevel; u++)
{
for (int j = 0; j < detailLevel; j++)
{
ScreenBuffer.SetPixel(stripe + u, y + j, color);
}
}
}
}
}
}
}
}
}
}
