void DrawTerrainColumn(int index, Vector3 corner)
{
// local tile map (we are rendering tile A)
// TileF TileD TileC
// TileE TileA TileB
// TileG TileH
// get this tile
Tile TileA = Memory[Row.This + ((index + 0) & 15)];
// check if object must be rendered with this tile
if (TileA.HoldsObject)
{
Row.ObjectCount++;
}
// check if tile is empty
if (TileA.IsEmpty)
{
return; // nothing to draw
}
// get base tile color
int colorIndex = TileA.ColorIndex;
// locate tile corners
// d +-------+ c
// / /|
// / / | x2 = x1 + Tile.WIDTH_X
// y1-- +-------+ | y2 = y1 + Tile.DEFAULT_HEIGHT_Y
// |a b| g+ --z2 z2 = z1 + Tile.DEPTH_Z
// | | /
// |e f|/
// y2-- +-------+ --z1
// | |
// x1 x2
float x1 = corner.X;
float x2 = x1 + Tile.WIDTH_X;
float z1 = corner.Z;
float z2 = corner.Z + Tile.DEPTH_Z;
// determine tile height offset
Tile TileB = Memory[Row.This + ((index + 1) & 15)];
Tile TileC = Memory[Row.Next + ((index + 1) & 15)];
Tile TileD = Memory[Row.Next + ((index + 0) & 15)];
TILE_HEIGHT height = GetTileHeight(TileA, TileB, TileC, TileD);
// draw left or right side of cube
if (x1 > 0)
{
// left side of the cube
TILE_HEIGHT side;
if (index == 1)
{
// leftmost tile
side.b = side.c = -Parent.ViewPosition.Y + Tile.DEFAULT_HEIGHT_Y;
}
else
{
Tile TileE = Memory[Row.This + ((index - 1) & 15)];
Tile TileF = Memory[Row.Next + ((index - 1) & 15)];
side = GetTileHeight(TileE, TileA, TileD, TileF);
}
// draw if tile to the left is lower than current tile
if (height.a < side.b || height.d < side.c)
{
Vertices[0] = Vector3.Transform(new Vector3(x1, height.a, z1), Parent.D3DTS_WORLD);
Vertices[1] = Vector3.Transform(new Vector3(x1, height.d, z2), Parent.D3DTS_WORLD);
Vertices[2] = Vector3.Transform(new Vector3(x1, side.c, z2), Parent.D3DTS_WORLD);
Vertices[3] = Vector3.Transform(new Vector3(x1, side.b, z1), Parent.D3DTS_WORLD);
DisplayListManager.AddPrimitive(renderMode, Vertices, 4, Parent.GetColor(colorIndex - 1));
}
}
else if (x2 < 0)
{
// right side of the cube
TILE_HEIGHT side;
if (index == 15)
{
// rightmost tile
side.a = side.d = -Parent.ViewPosition.Y + Tile.DEFAULT_HEIGHT_Y;
}
else
{
side = GetTileHeight(TileB, TileB, TileC, TileC);
}
// draw if tile to the right is lower than current tile
if (height.b < side.a || height.c < side.d)
{
Vertices[0] = Vector3.Transform(new Vector3(x2, height.b, z1), Parent.D3DTS_WORLD);
Vertices[1] = Vector3.Transform(new Vector3(x2, side.a, z1), Parent.D3DTS_WORLD);
Vertices[2] = Vector3.Transform(new Vector3(x2, side.d, z2), Parent.D3DTS_WORLD);
Vertices[3] = Vector3.Transform(new Vector3(x2, height.c, z2), Parent.D3DTS_WORLD);
DisplayListManager.AddPrimitive(renderMode, Vertices, 4, Parent.GetColor(colorIndex - 1));
}
}
// if tile is flat
if (TileA.IsFlat)
{
// Draw the front of the cube if:
// - This is the last row to render
// OR
// - Tile in front is lower than current tile (or empty)
TILE_HEIGHT side;
if (Row.Count == 0)
{
side.c = side.d = -Parent.ViewPosition.Y + Tile.DEFAULT_HEIGHT_Y;
}
else
{
Tile TileG = Memory[Row.Prev + ((index + 0) & 15)];
Tile TileH = Memory[Row.Prev + ((index + 10) & 15)];
side = GetTileHeight(TileG, TileH, TileB, TileA);
}
if (height.a < side.d || height.b < side.c)
{
Vertices[0] = Vector3.Transform(new Vector3(x1, height.a, z1), Parent.D3DTS_WORLD);
Vertices[1] = Vector3.Transform(new Vector3(x1, side.d, z1), Parent.D3DTS_WORLD);
Vertices[2] = Vector3.Transform(new Vector3(x2, side.c, z1), Parent.D3DTS_WORLD);
Vertices[3] = Vector3.Transform(new Vector3(x2, height.b, z1), Parent.D3DTS_WORLD);
DisplayListManager.AddPrimitive(renderMode, Vertices, 4, Parent.GetColor(colorIndex - 2));
}
}
// draw the top of the cube
Vertices[0] = Vector3.Transform(new Vector3(x1, height.a, z1), Parent.D3DTS_WORLD);
Vertices[1] = Vector3.Transform(new Vector3(x2, height.b, z1), Parent.D3DTS_WORLD);
Vertices[2] = Vector3.Transform(new Vector3(x2, height.c, z2), Parent.D3DTS_WORLD);
Vertices[3] = Vector3.Transform(new Vector3(x1, height.d, z2), Parent.D3DTS_WORLD);
DisplayListManager.AddPrimitive(renderMode, Vertices, 4, Parent.GetColor(colorIndex));
// special case for rendering solid sloped tiles
// this is done for maximum compatibility with real machine
if (!TileA.IsFlat && renderMode == Mathbox.RenderMode.Polygon)
{
DisplayListManager.AddPrimitive(Mathbox.RenderMode.Vector, Vertices, 4, Parent.GetColor(colorIndex));
}
// draw the bottom of the cube
Vertices[0] = Vector3.Transform(new Vector3(x1, -Parent.ViewPosition.Y + Tile.DEFAULT_HEIGHT_Y, z1), Parent.D3DTS_WORLD);
Vertices[1] = Vector3.Transform(new Vector3(x1, -Parent.ViewPosition.Y + Tile.DEFAULT_HEIGHT_Y, z2), Parent.D3DTS_WORLD);
Vertices[2] = Vector3.Transform(new Vector3(x2, -Parent.ViewPosition.Y + Tile.DEFAULT_HEIGHT_Y, z2), Parent.D3DTS_WORLD);
Vertices[3] = Vector3.Transform(new Vector3(x2, -Parent.ViewPosition.Y + Tile.DEFAULT_HEIGHT_Y, z1), Parent.D3DTS_WORLD);
DisplayListManager.AddPrimitive(renderMode, Vertices, 4, Parent.GetColor(colorIndex));
}
/// <summary>
/// Parses the list of objects to render
/// </summary>
/// <param name="address">base address of object list</param>
public void ParseObjectList(UInt16 address)
{
// address+0 Object position.X
// address+1 Object position.Y
// address+2 Object position.Z
// address+3 Object Instruction
// address+4 Address of view matrix
// address+5 Address of rotation matrix (only if specified by instruction)
// address+6 Address of surface list (only if specified by instruction)
// address +5 or + 7 first child object
#if false
Debug.WriteLine($"{Memory[address+0].HexString()} {Memory[address + 1].HexString()} {Memory[address + 2].HexString()} {Memory[address + 3].HexString()} {Memory[address + 4].HexString()} {Memory[address + 5].HexString()} {Memory[address + 6].HexString()}");
#endif
for (; ;)
{
// check for end of list
if (address == 0 || address >= 0x8000)
{
return;
}
// Control word encoding
// 0x8000 = stop flag
// 0x4000 = don't load camera matrix
// 0x1000 = ?
// 0x0800 = don't load base address or rotation matrix
// 0x0400 = x/y/z value is relative offset, not absolute position
Mathbox.ObjectInstruction opcode = Memory[address + 3];
// load camera matrix
if (!opcode.SkipObjectRotation)
{
Parent.LoadViewMatrix(Memory[address + 4]);
}
// Get new primitive list address and rotation matrix if they exist
int childAddr = address + 5;
if (!opcode.UsePreviousObjectPointsAndFaces)
{
PrimitiveListAddress = Memory[address + 6];
if (PrimitiveListAddress >= 0x8000)
{
return;
}
Parent.LoadRotationMatrix(Memory[address + 5]);
childAddr += 2;
}
// Don't render invalid objects
if (PrimitiveListAddress >= 0x8000)
{
return;
}
// Determine position of object
Vector3 pt = Parent.GetVectorAt(address);
if (opcode.ObjectPositionIsRelative)
{
// relative position
Parent.WorldPosition += Vector3.Transform(pt, Parent.ViewRotation);
}
else
{
// absolute position
pt -= Parent.ViewPosition;
Parent.WorldPosition = Vector3.Transform(pt, Parent.ViewRotation);
}
Parent.SetWorldMatrix(ref Parent.WorldPosition, ref Parent.WorldRotation);
#if WIDESCREEN_STARS
if (PrimitiveListAddress >= 0x4AE8 && PrimitiveListAddress <= 0x4B44)
{
for (int n = 0; n < Stars.Length; n++)
{
Vertices[n] = Vector3.Transform(Stars[n], Parent.D3DTS_WORLD);
}
DisplayListManager.AddPrimitive(Mathbox.RenderMode.Dot, Vertices, Stars.Length, Parent.GetColor(7));
return;
}
#endif
// parese the surfaces in this object
ParsePrimitiveList(PrimitiveListAddress);
// parse all child objects
for (; ;)
{
UInt16 child = Memory[childAddr++];
if (child == 0 || child >= 0x8000)
{
return;
}
if (child == 0x0002)
{
address += 8;
break;
}
ParseObjectList(child);
}
}
}
