using System;

namespace Hjg.Pngcs
{
	// Token: 0x0200001A RID: 26
	internal class PngDeinterlacer
	{
		// Token: 0x060000D4 RID: 212 RVA: 0x00004448 File Offset: 0x00002648
		internal PngDeinterlacer(ImageInfo iminfo)
		{
			this.imi = iminfo;
			this.pass = 0;
			if (this.imi.Packed)
			{
				this.packedValsPerPixel = 8 / this.imi.BitDepth;
				this.packedShift = this.imi.BitDepth;
				if (this.imi.BitDepth == 1)
				{
					this.packedMask = 128;
				}
				else if (this.imi.BitDepth == 2)
				{
					this.packedMask = 192;
				}
				else
				{
					this.packedMask = 240;
				}
			}
			else
			{
				this.packedMask = (this.packedShift = (this.packedValsPerPixel = 1));
			}
			this.setPass(1);
			this.setRow(0);
		}

		// Token: 0x060000D5 RID: 213 RVA: 0x00004514 File Offset: 0x00002714
		internal void setRow(int n)
		{
			this.currRowSubimg = n;
			this.currRowReal = n * this.dY + this.oY;
			if (this.currRowReal < 0 || this.currRowReal >= this.imi.Rows)
			{
				throw new PngjExceptionInternal("bad row - this should not happen");
			}
		}

		// Token: 0x060000D6 RID: 214 RVA: 0x00004564 File Offset: 0x00002764
		internal void setPass(int p)
		{
			if (this.pass == p)
			{
				return;
			}
			this.pass = p;
			switch (this.pass)
			{
			case 1:
				this.dY = (this.dX = 8);
				this.oX = (this.oY = 0);
				break;
			case 2:
				this.dY = (this.dX = 8);
				this.oX = 4;
				this.oY = 0;
				break;
			case 3:
				this.dX = 4;
				this.dY = 8;
				this.oX = 0;
				this.oY = 4;
				break;
			case 4:
				this.dX = (this.dY = 4);
				this.oX = 2;
				this.oY = 0;
				break;
			case 5:
				this.dX = 2;
				this.dY = 4;
				this.oX = 0;
				this.oY = 2;
				break;
			case 6:
				this.dX = (this.dY = 2);
				this.oX = 1;
				this.oY = 0;
				break;
			case 7:
				this.dX = 1;
				this.dY = 2;
				this.oX = 0;
				this.oY = 1;
				break;
			default:
				throw new PngjExceptionInternal("bad interlace pass" + this.pass);
			}
			this.rows = (this.imi.Rows - this.oY) / this.dY + 1;
			if ((this.rows - 1) * this.dY + this.oY >= this.imi.Rows)
			{
				this.rows--;
			}
			this.cols = (this.imi.Cols - this.oX) / this.dX + 1;
			if ((this.cols - 1) * this.dX + this.oX >= this.imi.Cols)
			{
				this.cols--;
			}
			if (this.cols == 0)
			{
				this.rows = 0;
			}
			this.dXsamples = this.dX * this.imi.Channels;
			this.oXsamples = this.oX * this.imi.Channels;
		}

		// Token: 0x060000D7 RID: 215 RVA: 0x0000479C File Offset: 0x0000299C
		internal void deinterlaceInt(int[] src, int[] dst, bool readInPackedFormat)
		{
			if (!this.imi.Packed || !readInPackedFormat)
			{
				int i = 0;
				int num = this.oXsamples;
				while (i < this.cols * this.imi.Channels)
				{
					for (int j = 0; j < this.imi.Channels; j++)
					{
						dst[num + j] = src[i + j];
					}
					i += this.imi.Channels;
					num += this.dXsamples;
				}
				return;
			}
			this.deinterlaceIntPacked(src, dst);
		}

		// Token: 0x060000D8 RID: 216 RVA: 0x0000481C File Offset: 0x00002A1C
		private void deinterlaceIntPacked(int[] src, int[] dst)
		{
			int num = this.packedMask;
			int num2 = -1;
			int i = 0;
			int num3 = this.oX;
			while (i < this.cols)
			{
				int num4 = i / this.packedValsPerPixel;
				num2++;
				if (num2 >= this.packedValsPerPixel)
				{
					num2 = 0;
				}
				num >>= this.packedShift;
				if (num2 == 0)
				{
					num = this.packedMask;
				}
				int num5 = num3 / this.packedValsPerPixel;
				int num6 = num3 % this.packedValsPerPixel;
				int num7 = src[num4] & num;
				int num8 = num6 - num2;
				if (num8 > 0)
				{
					num7 >>= num8 * this.packedShift;
				}
				else if (num8 < 0)
				{
					num7 <<= -num8 * this.packedShift;
				}
				dst[num5] |= num7;
				i++;
				num3 += this.dX;
			}
		}

		// Token: 0x060000D9 RID: 217 RVA: 0x000048F8 File Offset: 0x00002AF8
		internal void deinterlaceByte(byte[] src, byte[] dst, bool readInPackedFormat)
		{
			if (!this.imi.Packed || !readInPackedFormat)
			{
				int i = 0;
				int num = this.oXsamples;
				while (i < this.cols * this.imi.Channels)
				{
					for (int j = 0; j < this.imi.Channels; j++)
					{
						dst[num + j] = src[i + j];
					}
					i += this.imi.Channels;
					num += this.dXsamples;
				}
				return;
			}
			this.deinterlacePackedByte(src, dst);
		}

		// Token: 0x060000DA RID: 218 RVA: 0x00004978 File Offset: 0x00002B78
		private void deinterlacePackedByte(byte[] src, byte[] dst)
		{
			int num = this.packedMask;
			int num2 = -1;
			int i = 0;
			int num3 = this.oX;
			while (i < this.cols)
			{
				int num4 = i / this.packedValsPerPixel;
				num2++;
				if (num2 >= this.packedValsPerPixel)
				{
					num2 = 0;
				}
				num >>= this.packedShift;
				if (num2 == 0)
				{
					num = this.packedMask;
				}
				int num5 = num3 / this.packedValsPerPixel;
				int num6 = num3 % this.packedValsPerPixel;
				int num7 = (int)src[num4] & num;
				int num8 = num6 - num2;
				if (num8 > 0)
				{
					num7 >>= num8 * this.packedShift;
				}
				else if (num8 < 0)
				{
					num7 <<= -num8 * this.packedShift;
				}
				int num9 = num5;
				dst[num9] |= (byte)num7;
				i++;
				num3 += this.dX;
			}
		}

		// Token: 0x060000DB RID: 219 RVA: 0x00004A55 File Offset: 0x00002C55
		internal bool isAtLastRow()
		{
			return this.pass == 7 && this.currRowSubimg == this.rows - 1;
		}

		// Token: 0x060000DC RID: 220 RVA: 0x00004A72 File Offset: 0x00002C72
		internal int getCurrRowSubimg()
		{
			return this.currRowSubimg;
		}

		// Token: 0x060000DD RID: 221 RVA: 0x00004A7A File Offset: 0x00002C7A
		internal int getCurrRowReal()
		{
			return this.currRowReal;
		}

		// Token: 0x060000DE RID: 222 RVA: 0x00004A82 File Offset: 0x00002C82
		internal int getPass()
		{
			return this.pass;
		}

		// Token: 0x060000DF RID: 223 RVA: 0x00004A8A File Offset: 0x00002C8A
		internal int getRows()
		{
			return this.rows;
		}

		// Token: 0x060000E0 RID: 224 RVA: 0x00004A92 File Offset: 0x00002C92
		internal int getCols()
		{
			return this.cols;
		}

		// Token: 0x060000E1 RID: 225 RVA: 0x00004A9A File Offset: 0x00002C9A
		internal int getPixelsToRead()
		{
			return this.getCols();
		}

		// Token: 0x060000E2 RID: 226 RVA: 0x00004AA2 File Offset: 0x00002CA2
		internal int[][] getImageInt()
		{
			return this.imageInt;
		}

		// Token: 0x060000E3 RID: 227 RVA: 0x00004AAA File Offset: 0x00002CAA
		internal void setImageInt(int[][] imageInt)
		{
			this.imageInt = imageInt;
		}

		// Token: 0x060000E4 RID: 228 RVA: 0x00004AB3 File Offset: 0x00002CB3
		internal byte[][] getImageByte()
		{
			return this.imageByte;
		}

		// Token: 0x060000E5 RID: 229 RVA: 0x00004ABB File Offset: 0x00002CBB
		internal void setImageByte(byte[][] imageByte)
		{
			this.imageByte = imageByte;
		}

		// Token: 0x04000076 RID: 118
		private readonly ImageInfo imi;

		// Token: 0x04000077 RID: 119
		private int pass;

		// Token: 0x04000078 RID: 120
		private int rows;

		// Token: 0x04000079 RID: 121
		private int cols;

		// Token: 0x0400007A RID: 122
		private int dY;

		// Token: 0x0400007B RID: 123
		private int dX;

		// Token: 0x0400007C RID: 124
		private int oY;

		// Token: 0x0400007D RID: 125
		private int oX;

		// Token: 0x0400007E RID: 126
		private int oXsamples;

		// Token: 0x0400007F RID: 127
		private int dXsamples;

		// Token: 0x04000080 RID: 128
		private int currRowSubimg = -1;

		// Token: 0x04000081 RID: 129
		private int currRowReal = -1;

		// Token: 0x04000082 RID: 130
		private readonly int packedValsPerPixel;

		// Token: 0x04000083 RID: 131
		private readonly int packedMask;

		// Token: 0x04000084 RID: 132
		private readonly int packedShift;

		// Token: 0x04000085 RID: 133
		private int[][] imageInt;

		// Token: 0x04000086 RID: 134
		private byte[][] imageByte;
	}
}