Entity component that draws square and circle shadows beneath entities.

public unsafe sealed class ShadowComponent { Game game; Entity entity; public ShadowComponent( Game game, Entity entity ) { this.game = game; this.entity = entity; } internal void Draw() { EntityShadow mode = game.Players.ShadowMode; Vector3 Position = entity.Position; float posX = Position.X, posZ = Position.Z; int posY = Math.Min( (int)Position.Y, game.Map.Height - 1 ); int index = 0, vb = 0; VertexPos3fTex2fCol4b[] verts = null; int posCount = 0, dataCount = 0; Vector3I* coords = stackalloc Vector3I[4]; ShadowData* data = stackalloc ShadowData[4]; for( int i = 0; i < 4; i++ ) { coords[i] = new Vector3I( int.MinValue ); data[i] = new ShadowData(); } if( mode == EntityShadow.SnapToBlock ) { vb = game.Graphics.texVb; verts = game.Graphics.texVerts; if( !GetBlocks( coords, ref posCount, posX, posZ, posY, data, ref dataCount ) ) return; float x1 = Utils.Floor( posX ), z1 = Utils.Floor( posZ ); DraqSquareShadow( verts, ref index, data[0].Y, 220, x1, z1 ); } else { vb = game.ModelCache.vb; verts = game.ModelCache.vertices; float x = posX - 7/16f, z = posZ - 7/16f; if( GetBlocks( coords, ref posCount, x, z, posY, data, ref dataCount ) && data[0].A > 0 ) DrawCircle( verts, ref index, data, dataCount, x, z ); x = Math.Max( posX - 7/16f, Utils.Floor( posX + 7/16f ) ); if( GetBlocks( coords, ref posCount, x, z, posY, data, ref dataCount ) && data[0].A > 0 ) DrawCircle( verts, ref index, data, dataCount, x, z ); z = Math.Max( posZ - 7/16f, Utils.Floor( posZ + 7/16f ) ); if( GetBlocks( coords, ref posCount, x, z, posY, data, ref dataCount ) && data[0].A > 0 ) DrawCircle( verts, ref index, data, dataCount, x, z ); x = posX - 7/16f; if( GetBlocks( coords, ref posCount, x, z, posY, data, ref dataCount ) && data[0].A > 0 ) DrawCircle( verts, ref index, data, dataCount, x, z ); } if( index == 0 ) return; CheckShadowTexture( game.Graphics ); if( !boundShadowTex ) { game.Graphics.BindTexture( shadowTex ); boundShadowTex = true; } game.Graphics.UpdateDynamicIndexedVb( DrawMode.Triangles, vb, verts, index, index * 6 / 4 ); } void DraqSquareShadow( VertexPos3fTex2fCol4b[] verts, ref int index, float y, byte alpha, float x, float z ) { FastColour col = FastColour.White; col.A = alpha; TextureRec rec = new TextureRec( 63/128f, 63/128f, 1/128f, 1/128f ); verts[index++] = new VertexPos3fTex2fCol4b( x, y, z, rec.U1, rec.V1, col ); verts[index++] = new VertexPos3fTex2fCol4b( x + 1, y, z, rec.U2, rec.V1, col ); verts[index++] = new VertexPos3fTex2fCol4b( x + 1, y, z + 1, rec.U2, rec.V2, col ); verts[index++] = new VertexPos3fTex2fCol4b( x, y, z + 1, rec.U1, rec.V2, col ); } void DrawCircle( VertexPos3fTex2fCol4b[] verts, ref int index, ShadowData* data, int dataCount, float x, float z ) { x = Utils.Floor( x ); z = Utils.Floor( z ); BlockInfo info = game.BlockInfo; Vector3 min = info.MinBB[data[0].Block], max = info.MaxBB[data[0].Block]; DrawCoords( verts, ref index, data[0], x + min.X, z + min.Z, x + max.X, z + max.Z ); for( int i = 1; i < dataCount; i++ ) { Vector3 nMin = info.MinBB[data[i].Block], nMax = info.MaxBB[data[i].Block]; DrawCoords( verts, ref index, data[i], x + min.X, z + nMin.Z, x + max.X, z + min.Z ); DrawCoords( verts, ref index, data[i], x + min.X, z + max.Z, x + max.X, z + nMax.Z ); DrawCoords( verts, ref index, data[i], x + nMin.X, z + nMin.Z, x + min.X, z + nMax.Z ); DrawCoords( verts, ref index, data[i], x + max.X, z + nMin.Z, x + nMax.X, z + nMax.Z ); min = nMin; max = nMax; } } void DrawCoords( VertexPos3fTex2fCol4b[] verts, ref int index, ShadowData data, float x1, float z1, float x2, float z2 ) { Vector3 centre = entity.Position; BlockInfo info = game.BlockInfo; if( lequal( x2, x1 ) || lequal( z2, z1 ) ) return; float u1 = (x1 - centre.X) * 16/14f + 0.5f; float v1 = (z1 - centre.Z) * 16/14f + 0.5f; float u2 = (x2 - centre.X) * 16/14f + 0.5f; float v2 = (z2 - centre.Z) * 16/14f + 0.5f; if( u2 <= 0 || v2 <= 0 || u1 >= 1 || v1 >= 1 ) return; x1 = Math.Max( x1, centre.X - 7/16f ); u1 = Math.Max( u1, 0 ); z1 = Math.Max( z1, centre.Z - 7/16f ); v1 = Math.Max( v1, 0 ); x2 = Math.Min( x2, centre.X + 7/16f ); u2 = Math.Min( u2, 1 ); z2 = Math.Min( z2, centre.Z + 7/16f ); v2 = Math.Min( v2, 1 ); FastColour col = FastColour.White; col.A = data.A; verts[index++] = new VertexPos3fTex2fCol4b( x1, data.Y, z1, u1, v1, col ); verts[index++] = new VertexPos3fTex2fCol4b( x2, data.Y, z1, u2, v1, col ); verts[index++] = new VertexPos3fTex2fCol4b( x2, data.Y, z2, u2, v2, col ); verts[index++] = new VertexPos3fTex2fCol4b( x1, data.Y, z2, u1, v2, col ); } bool GetBlocks( Vector3I* coords, ref int posCount, float x, float z, int posY, ShadowData* data, ref int index ) { int blockX = Utils.Floor( x ), blockZ = Utils.Floor( z ); Vector3I p = new Vector3I( blockX, 0, blockZ ); BlockInfo info = game.BlockInfo; Vector3 Position = entity.Position; index = 0; // Check we have not processed this particular block already. if( Position.Y < 0 ) return false; for( int i = 0; i < 4; i++ ) { if( coords[i] == p ) return false; data[i] = new ShadowData(); } coords[posCount] = p; posCount++; while( posY >= 0 && index < 4 ) { byte block = GetShadowBlock( blockX, posY, blockZ ); posY--; if( info.IsAir[block] || info.IsSprite[block] || info.IsLiquid[block] ) continue; float blockY = posY + 1 + info.MaxBB[block].Y; if( blockY >= Position.Y + 0.01f ) continue; data[index].Block = block; data[index].Y = blockY; CalcAlpha( Position.Y, ref data[index] ); index++; // Check if the casted shadow will continue on further down. if( info.MinBB[block].X == 0 && info.MaxBB[block].X == 1 && info.MinBB[block].Z == 0 && info.MaxBB[block].Z == 1 ) return true; } if( index < 4 ) { data[index].Block = (byte)game.Map.EdgeBlock; data[index].Y = 0; CalcAlpha( Position.Y, ref data[index] ); index++; } return true; } byte GetShadowBlock( int x, int y, int z ) { if( x < 0 || z < 0 || x >= game.Map.Width || z >= game.Map.Length ) { if( y == game.Map.EdgeHeight - 1 ) return (byte)(game.BlockInfo.IsAir[(byte)game.Map.EdgeBlock] ? 0 : Block.Bedrock); if( y == game.Map.SidesHeight - 1 ) return (byte)(game.BlockInfo.IsAir[(byte)game.Map.SidesBlock] ? 0 : Block.Bedrock); return (byte)Block.Air; } return game.Map.GetBlock( x, y, z ); } struct ShadowData { public byte Block; public float Y; public byte A; } static void CalcAlpha( float playerY, ref ShadowData data ) { float y = data.Y; if( (playerY - y) <= 6 ) { data.A = (byte)(190 - 190 * (playerY - y) / 6); data.Y += 1/64f; return; } data.A = 0; if( (playerY - y) <= 16 ) data.Y += 1/64f; else if( (playerY - y) <= 32 ) data.Y += 1/16f; else if( (playerY - y) <= 96 ) data.Y += 1/8f; else data.Y += 1/4f; } static bool lequal(float a, float b) { return a < b || Math.Abs(a - b) < 0.001f; } internal static bool boundShadowTex = false; internal static int shadowTex = -1; static void CheckShadowTexture( IGraphicsApi graphics ) { if( shadowTex != -1 ) return; const int size = 128, half = size / 2; using( Bitmap bmp = new Bitmap( size, size ) ) using( FastBitmap fastBmp = new FastBitmap( bmp, true, false ) ) { int inPix = new FastColour( 0, 0, 0, 200 ).ToArgb(); int outPix = inPix & 0xFFFFFF; for( int y = 0; y < fastBmp.Height; y++ ) { int* row = fastBmp.GetRowPtr( y ); for( int x = 0; x < fastBmp.Width; x++ ) { double dist = (half - (x + 0.5)) * (half - (x + 0.5)) + (half - (y + 0.5)) * (half - (y + 0.5)); row[x] = dist < half * half ? inPix : outPix; } } shadowTex = graphics.CreateTexture( fastBmp ); } } } }