public Texture2D Render(RayCasterCamera rayCasterCamera, RayCasterMap rayCasterMap)
{
// Based on the raycaster tutorial at
// http://www.student.kuleuven.be/~m0216922/CG/raycasting.html
// Clear the screen
for (int i = 0; i < m_ScreenWidth * m_ScreenHeight; i++)
m_Data[i] = 0;
// For each horizontal pixel
for(int x=0;x<m_ScreenWidth;x++)
{
double cameraX = 2 * x / (double)(m_ScreenWidth) - 1; //x-coordinate in RayCasterCamera space
double rayPosX = rayCasterCamera.Position.X;
double rayPosY = rayCasterCamera.Position.Y;
double rayDirX = rayCasterCamera.Direction.X + rayCasterCamera.VectorPlane.X * cameraX;
double rayDirY = rayCasterCamera.Direction.Y + rayCasterCamera.VectorPlane.Y * cameraX;
//which box of the RayCasterMap we're in
int mapX = (int)(rayPosX);
int mapY = (int)(rayPosY);
//length of ray from current position to next x or y-side
double sideDistX;
double sideDistY;
//length of ray from one x or y-side to next x or y-side
double deltaDistX = Math.Sqrt(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX));
double deltaDistY = Math.Sqrt(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY));
double perpWallDist;
//what direction to step in x or y-direction (either +1 or -1)
int stepX;
int stepY;
int hit = 0; //was there a wall hit?
int side = 0; //was a NS or a EW wall hit?
//calculate step and initial sideDist
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;
}
//perform DDA
while (hit == 0)
{
//jump to next RayCasterMap square, OR in x-direction, OR in y-direction
if (sideDistX < sideDistY)
{
sideDistX += deltaDistX;
mapX += stepX;
side = 0;
}
else
{
sideDistY += deltaDistY;
mapY += stepY;
side = 1;
}
//Check if ray has hit a wall
if (rayCasterMap.WorldMap[mapX,mapY] > 0) hit = 1;
}
//Calculate distance projected on RayCasterCamera direction (oblique distance will give fisheye effect!)
if (side == 0)
perpWallDist = Math.Abs((mapX - rayPosX + (1 - stepX) / 2) / rayDirX);
else
perpWallDist = Math.Abs((mapY - rayPosY + (1 - stepY) / 2) / rayDirY);
//Calculate height of line to draw on screen
int lineHeight = Math.Abs((int)(m_ScreenHeight / perpWallDist));
//calculate lowest and highest pixel to fill in current stripe
int drawStart = -lineHeight / 2 + m_ScreenHeight / 2;
if(drawStart < 0)
drawStart = 0;
int drawEnd = lineHeight / 2 + m_ScreenHeight / 2;
if (drawEnd >= m_ScreenHeight)
drawEnd = m_ScreenHeight - 1;
//texturing calculations
int texNum = rayCasterMap.WorldMap[mapX,mapY] - 1; //1 subtracted from it so that texture 0 can be used!
//calculate value of wallX
double wallX; //where exactly the wall was hit
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);
//x coordinate on the texture
var texX = (int)((wallX) * (double)TextureWidth);
if(side == 0 && rayDirX > 0) texX = TextureWidth - texX - 1;
if(side == 1 && rayDirY < 0) texX = TextureWidth - texX - 1;
m_CurrentTexture = m_TextureLibrary[texNum];
int index = x + (m_ScreenWidth * drawStart);
for (int y = drawStart; y < drawEnd; y++)
{
var d = y * 256 - m_ScreenHeight * 128 + lineHeight * 128;
var texY = ((d * TextureHeight) / lineHeight) / 256;
// Darkness Calculations
var dval = (int)(perpWallDist *2);
dval = Math.Min(47, dval);
var color = m_CurrentTexture.Texture[dval][texX, texY];
index += m_ScreenWidth;
m_Data[index] = color;
}
// Floor Casting
double floorXWall, floorYWall; //x, y position of the floor texel at the bottom of the wall
//4 different wall directions possible
if(side == 0 && rayDirX > 0)
{
floorXWall = mapX;
floorYWall = mapY + wallX;
}
else if(side == 0 && rayDirX < 0)
{
floorXWall = mapX + 1.0;
floorYWall = mapY + wallX;
}
else if(side == 1 && rayDirY > 0)
{
floorXWall = mapX + wallX;
floorYWall = mapY;
}
else
{
floorXWall = mapX + wallX;
floorYWall = mapY + 1.0;
}
double distWall = perpWallDist;
double distPlayer = 0.0;
m_FloorTexture = m_TextureLibrary[4];
m_CeilingTexture = m_TextureLibrary[4];
if (drawEnd < 0)
drawEnd = m_ScreenHeight;
//Draw the floor from drawEnd to the bottom of the screen
for(int y = drawEnd + 1; y < m_ScreenHeight; y++)
{
double currentDist = m_LookupTableFloorDist[y];
double weight = (currentDist - distPlayer) / (distWall - distPlayer);
double currentFloorX = weight * floorXWall + (1.0 - weight) * rayCasterCamera.Position.X;
double currentFloorY = weight * floorYWall + (1.0 - weight) * rayCasterCamera.Position.Y;
const int texWidth = 64;
const int texHeight = 64;
var floorTexX = (int) (currentFloorX * 64) % texWidth;
var floorTexY = (int) (currentFloorY * 64) % texHeight;
var dval = (int)(currentDist * 2);
dval = Math.Min(47, dval);
var floorColor = m_FloorTexture.Texture[dval][floorTexY, floorTexX];
var ceilingColor = m_CeilingTexture.Texture[dval][floorTexY, floorTexX];
// Write pixel
m_Data[m_FIndexLookup[x,y]] = floorColor;
m_Data[m_CIndexLoopup[x,y]] = ceilingColor;
}
}
// Write the data to the texture
m_RenderTarget.SetData(m_Data);
return m_RenderTarget;
}
public Texture2D Render(RayCasterCamera rayCasterCamera, RayCasterMap rayCasterMap)
{
// Based on the raycaster tutorial at
// http://www.student.kuleuven.be/~m0216922/CG/raycasting.html
// Clear the screen
for (int i = 0; i < m_ScreenWidth * m_ScreenHeight; i++)
{
m_Data[i] = 0;
}
// For each horizontal pixel
for (int x = 0; x < m_ScreenWidth; x++)
{
double cameraX = 2 * x / (double)(m_ScreenWidth) - 1; //x-coordinate in RayCasterCamera space
double rayPosX = rayCasterCamera.Position.X;
double rayPosY = rayCasterCamera.Position.Y;
double rayDirX = rayCasterCamera.Direction.X + rayCasterCamera.VectorPlane.X * cameraX;
double rayDirY = rayCasterCamera.Direction.Y + rayCasterCamera.VectorPlane.Y * cameraX;
//which box of the RayCasterMap we're in
int mapX = (int)(rayPosX);
int mapY = (int)(rayPosY);
//length of ray from current position to next x or y-side
double sideDistX;
double sideDistY;
//length of ray from one x or y-side to next x or y-side
double deltaDistX = Math.Sqrt(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX));
double deltaDistY = Math.Sqrt(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY));
double perpWallDist;
//what direction to step in x or y-direction (either +1 or -1)
int stepX;
int stepY;
int hit = 0; //was there a wall hit?
int side = 0; //was a NS or a EW wall hit?
//calculate step and initial sideDist
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;
}
//perform DDA
while (hit == 0)
{
//jump to next RayCasterMap square, OR in x-direction, OR in y-direction
if (sideDistX < sideDistY)
{
sideDistX += deltaDistX;
mapX += stepX;
side = 0;
}
else
{
sideDistY += deltaDistY;
mapY += stepY;
side = 1;
}
//Check if ray has hit a wall
if (rayCasterMap.WorldMap[mapX, mapY] > 0)
{
hit = 1;
}
}
//Calculate distance projected on RayCasterCamera direction (oblique distance will give fisheye effect!)
if (side == 0)
{
perpWallDist = Math.Abs((mapX - rayPosX + (1 - stepX) / 2) / rayDirX);
}
else
{
perpWallDist = Math.Abs((mapY - rayPosY + (1 - stepY) / 2) / rayDirY);
}
//Calculate height of line to draw on screen
int lineHeight = Math.Abs((int)(m_ScreenHeight / perpWallDist));
//calculate lowest and highest pixel to fill in current stripe
int drawStart = -lineHeight / 2 + m_ScreenHeight / 2;
if (drawStart < 0)
{
drawStart = 0;
}
int drawEnd = lineHeight / 2 + m_ScreenHeight / 2;
if (drawEnd >= m_ScreenHeight)
{
drawEnd = m_ScreenHeight - 1;
}
//texturing calculations
int texNum = rayCasterMap.WorldMap[mapX, mapY] - 1; //1 subtracted from it so that texture 0 can be used!
//calculate value of wallX
double wallX; //where exactly the wall was hit
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);
//x coordinate on the texture
var texX = (int)((wallX) * (double)TextureWidth);
if (side == 0 && rayDirX > 0)
{
texX = TextureWidth - texX - 1;
}
if (side == 1 && rayDirY < 0)
{
texX = TextureWidth - texX - 1;
}
m_CurrentTexture = m_TextureLibrary[texNum];
int index = x + (m_ScreenWidth * drawStart);
for (int y = drawStart; y < drawEnd; y++)
{
var d = y * 256 - m_ScreenHeight * 128 + lineHeight * 128;
var texY = ((d * TextureHeight) / lineHeight) / 256;
// Darkness Calculations
var dval = (int)(perpWallDist * 2);
dval = Math.Min(47, dval);
var color = m_CurrentTexture.Texture[dval][texX, texY];
index += m_ScreenWidth;
m_Data[index] = color;
}
// Floor Casting
double floorXWall, floorYWall; //x, y position of the floor texel at the bottom of the wall
//4 different wall directions possible
if (side == 0 && rayDirX > 0)
{
floorXWall = mapX;
floorYWall = mapY + wallX;
}
else if (side == 0 && rayDirX < 0)
{
floorXWall = mapX + 1.0;
floorYWall = mapY + wallX;
}
else if (side == 1 && rayDirY > 0)
{
floorXWall = mapX + wallX;
floorYWall = mapY;
}
else
{
floorXWall = mapX + wallX;
floorYWall = mapY + 1.0;
}
double distWall = perpWallDist;
double distPlayer = 0.0;
m_FloorTexture = m_TextureLibrary[4];
m_CeilingTexture = m_TextureLibrary[4];
if (drawEnd < 0)
{
drawEnd = m_ScreenHeight;
}
//Draw the floor from drawEnd to the bottom of the screen
for (int y = drawEnd + 1; y < m_ScreenHeight; y++)
{
double currentDist = m_LookupTableFloorDist[y];
double weight = (currentDist - distPlayer) / (distWall - distPlayer);
double currentFloorX = weight * floorXWall + (1.0 - weight) * rayCasterCamera.Position.X;
double currentFloorY = weight * floorYWall + (1.0 - weight) * rayCasterCamera.Position.Y;
const int texWidth = 64;
const int texHeight = 64;
var floorTexX = (int)(currentFloorX * 64) % texWidth;
var floorTexY = (int)(currentFloorY * 64) % texHeight;
var dval = (int)(currentDist * 2);
dval = Math.Min(47, dval);
var floorColor = m_FloorTexture.Texture[dval][floorTexY, floorTexX];
var ceilingColor = m_CeilingTexture.Texture[dval][floorTexY, floorTexX];
// Write pixel
m_Data[m_FIndexLookup[x, y]] = floorColor;
m_Data[m_CIndexLoopup[x, y]] = ceilingColor;
}
}
// Write the data to the texture
m_RenderTarget.SetData(m_Data);
return(m_RenderTarget);
}
public void AddRayCasterTexture(RayCasterTexture texture)
{
m_TextureLibrary.Add(texture);
}
public void AddRayCasterTexture(RayCasterTexture texture)
{
m_TextureLibrary.Add(texture);
}
