mirror of
https://github.com/fadden/6502bench.git
synced 2024-11-29 10:50:28 +00:00
349 lines
14 KiB
C#
349 lines
14 KiB
C#
|
/*
|
|||
|
|
* Copyright 2019 faddenSoft
|
|||
|
|
*
|
|||
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|||
|
|
* you may not use this file except in compliance with the License.
|
|||
|
|
* You may obtain a copy of the License at
|
|||
|
|
*
|
|||
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|||
|
|
*
|
|||
|
|
* Unless required by applicable law or agreed to in writing, software
|
|||
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|||
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|||
|
|
* See the License for the specific language governing permissions and
|
|||
|
|
* limitations under the License.
|
|||
|
|
*/
|
|||
|
|
using System;
|
|||
|
|
using System.Collections.Generic;
|
|||
|
|
using System.Diagnostics;
|
|||
|
|
using System.Text;
|
|||
|
|
|
|||
|
|
namespace CommonUtil {
|
|||
|
|
/// <summary>
|
|||
|
|
/// Representation of a GIF image, with the various pieces broken out.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <remarks>
|
|||
|
|
/// This has only been tested with the GIF images created by the Windows Media GifEncoder,
|
|||
|
|
/// which are GIF89a with no global color table.
|
|||
|
|
/// </remarks>
|
|||
|
|
public class UnpackedGif {
|
|||
|
|
//
|
|||
|
|
// Header.
|
|||
|
|
//
|
|||
|
|
public enum FileVersion { Unknown = 0, Gif87a, Gif89a };
|
|||
|
|
private static readonly byte[] GIF87A = new byte[] {
|
|||
|
|
(byte)'G', (byte)'I', (byte)'F', (byte)'8', (byte)'7', (byte)'a'
|
|||
|
|
};
|
|||
|
|
private static readonly byte[] GIF89A = new byte[] {
|
|||
|
|
(byte)'G', (byte)'I', (byte)'F', (byte)'8', (byte)'9', (byte)'a'
|
|||
|
|
};
|
|||
|
|
public FileVersion FileVer { get; private set; }
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Logical screen descriptor.
|
|||
|
|
//
|
|||
|
|
public ushort LogicalScreenWidth { get; private set; }
|
|||
|
|
public ushort LogicalScreenHeight { get; private set; }
|
|||
|
|
public bool GlobalColorTableFlag { get; private set; }
|
|||
|
|
public byte ColorResolution { get; private set; }
|
|||
|
|
public bool SortFlag { get; private set; }
|
|||
|
|
public byte GlobalColorTableSize { get; private set; }
|
|||
|
|
public byte BackgroundColorIndex { get; private set; }
|
|||
|
|
public byte PixelAspectRatio { get; private set; }
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Global color table.
|
|||
|
|
//
|
|||
|
|
public byte[] GlobalColorTable { get; private set; }
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Extension block constants.
|
|||
|
|
//
|
|||
|
|
public const byte EXTENSION_INTRODUCER = 0x21;
|
|||
|
|
public const byte APP_EXTENSION_LABEL = 0xff;
|
|||
|
|
public const byte COMMENT_LABEL = 0xfe;
|
|||
|
|
public const byte GRAPHIC_CONTROL_LABEL = 0xf9;
|
|||
|
|
public const byte PLAIN_TEXT_LABEL = 0x01;
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Graphic control extension.
|
|||
|
|
//
|
|||
|
|
// These are optional. At most one may precede a graphic rendering block.
|
|||
|
|
//
|
|||
|
|
public class GraphicControlExtension {
|
|||
|
|
public enum DisposalMethods : byte {
|
|||
|
|
None = 0,
|
|||
|
|
DoNotDispose = 1,
|
|||
|
|
RestoreBackground = 2,
|
|||
|
|
RestorePrevious = 3
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
public byte DisposalMethod { get; private set; }
|
|||
|
|
public bool UserInputFlag { get; private set; }
|
|||
|
|
public bool TransparencyFlag { get; private set; }
|
|||
|
|
public ushort DelayTime { get; private set; }
|
|||
|
|
public byte TransparentColorIndex { get; private set; }
|
|||
|
|
|
|||
|
|
private GraphicControlExtension() { }
|
|||
|
|
|
|||
|
|
public static GraphicControlExtension Create(byte[] data, ref int offset) {
|
|||
|
|
Debug.Assert(data[offset] == EXTENSION_INTRODUCER &&
|
|||
|
|
data[offset + 1] == GRAPHIC_CONTROL_LABEL);
|
|||
|
|
|
|||
|
|
GraphicControlExtension gce = new GraphicControlExtension();
|
|||
|
|
|
|||
|
|
offset += 2;
|
|||
|
|
if (data[offset++] != 4) {
|
|||
|
|
Debug.WriteLine("Bad block size in GCE data");
|
|||
|
|
return null;
|
|||
|
|
}
|
|||
|
|
byte pak = data[offset++];
|
|||
|
|
gce.DisposalMethod = (byte)((pak >> 2) & 0x07);
|
|||
|
|
gce.UserInputFlag = (pak & 0x02) != 0;
|
|||
|
|
gce.TransparencyFlag = (pak & 0x01) != 0;
|
|||
|
|
gce.DelayTime = RawData.FetchLittleUshort(data, ref offset);
|
|||
|
|
gce.TransparentColorIndex = data[offset++];
|
|||
|
|
if (data[offset++] != 0) {
|
|||
|
|
Debug.WriteLine("Missing termination in GCE data");
|
|||
|
|
return null;
|
|||
|
|
}
|
|||
|
|
return gce;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Image descriptor.
|
|||
|
|
//
|
|||
|
|
public const byte IMAGE_SEPARATOR = 0x2c;
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// The graphic rendering block is an image descriptor, followed by an optional
|
|||
|
|
/// local color table, and then the image data itself.
|
|||
|
|
/// </summary>
|
|||
|
|
public class GraphicRenderingBlock {
|
|||
|
|
public ushort ImageLeftPosition { get; private set; }
|
|||
|
|
public ushort ImageTopPosition { get; private set; }
|
|||
|
|
public ushort ImageWidth { get; private set; }
|
|||
|
|
public ushort ImageHeight { get; private set; }
|
|||
|
|
public bool LocalColorTableFlag { get; private set; }
|
|||
|
|
public bool InterlaceFlag { get; private set; }
|
|||
|
|
public bool SortFlag { get; private set; }
|
|||
|
|
public byte LocalColorTableSize { get; private set; }
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Local color table.
|
|||
|
|
//
|
|||
|
|
public byte[] LocalColorTable { get; private set; }
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Offset of first byte of image data (which will be the LZW minimum code size byte).
|
|||
|
|
/// </summary>
|
|||
|
|
public int ImageStartOffset { get; private set; }
|
|||
|
|
|
|||
|
|
public byte[] ImageData { get; private set; }
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Offset of last byte of image data (which will be the terminating $00 byte).
|
|||
|
|
/// </summary>
|
|||
|
|
public int ImageEndOffset { get; private set; }
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Optional extension with transparency and delay values.
|
|||
|
|
/// </summary>
|
|||
|
|
public GraphicControlExtension GraphicControlExt { get; set; }
|
|||
|
|
|
|||
|
|
private GraphicRenderingBlock() { }
|
|||
|
|
|
|||
|
|
public static GraphicRenderingBlock Create(byte[] data, ref int offset) {
|
|||
|
|
GraphicRenderingBlock grb = new GraphicRenderingBlock();
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Image descriptor.
|
|||
|
|
//
|
|||
|
|
Debug.Assert(data[offset] == IMAGE_SEPARATOR);
|
|||
|
|
offset++;
|
|||
|
|
grb.ImageLeftPosition = RawData.FetchLittleUshort(data, ref offset);
|
|||
|
|
grb.ImageTopPosition = RawData.FetchLittleUshort(data, ref offset);
|
|||
|
|
grb.ImageWidth = RawData.FetchLittleUshort(data, ref offset);
|
|||
|
|
grb.ImageHeight = RawData.FetchLittleUshort(data, ref offset);
|
|||
|
|
byte pak = data[offset++];
|
|||
|
|
grb.LocalColorTableFlag = (pak & 0x80) != 0;
|
|||
|
|
grb.InterlaceFlag = (pak & 0x40) != 0;
|
|||
|
|
grb.SortFlag = (pak & 0x20) != 0;
|
|||
|
|
grb.LocalColorTableSize = (byte)(pak & 0x07);
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Local color table (optional).
|
|||
|
|
//
|
|||
|
|
if (grb.LocalColorTableFlag) {
|
|||
|
|
// Size is expressed as a power of 2. TableSize=7 is 256 entries, 3 bytes each.
|
|||
|
|
int tableLen = 1 << (grb.LocalColorTableSize + 1);
|
|||
|
|
grb.LocalColorTable = new byte[tableLen * 3];
|
|||
|
|
for (int i = 0; i < tableLen * 3; i++) {
|
|||
|
|
grb.LocalColorTable[i] = data[offset++];
|
|||
|
|
}
|
|||
|
|
} else {
|
|||
|
|
grb.LocalColorTable = new byte[0];
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Table based image data.
|
|||
|
|
//
|
|||
|
|
grb.ImageData = data;
|
|||
|
|
grb.ImageStartOffset = offset++;
|
|||
|
|
while (data[offset] != 0) {
|
|||
|
|
offset += data[offset] + 1;
|
|||
|
|
}
|
|||
|
|
grb.ImageEndOffset = offset++;
|
|||
|
|
|
|||
|
|
return grb;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
public List<GraphicRenderingBlock> ImageBlocks = new List<GraphicRenderingBlock>();
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// EOF marker.
|
|||
|
|
//
|
|||
|
|
public const byte GIF_TRAILER = 0x3b;
|
|||
|
|
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Constructor. Internal only; use factory method.
|
|||
|
|
/// </summary>
|
|||
|
|
private UnpackedGif() { }
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="gifData">GIF data stream. The array may be longer than the
|
|||
|
|
/// data stream.</param>
|
|||
|
|
/// <returns>Newly-created object, or null on error.</returns>
|
|||
|
|
public static UnpackedGif Create(byte[] gifData) {
|
|||
|
|
UnpackedGif gif = new UnpackedGif();
|
|||
|
|
|
|||
|
|
try {
|
|||
|
|
if (!gif.Unpack(gifData)) {
|
|||
|
|
return null;
|
|||
|
|
}
|
|||
|
|
} catch (Exception ex) {
|
|||
|
|
Debug.WriteLine("Failure during GIF unpacking: " + ex);
|
|||
|
|
return null;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return gif;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
private bool Unpack(byte[] gifData) {
|
|||
|
|
//
|
|||
|
|
// Header. Signature ("GIF") + version ("87a" or "89a").
|
|||
|
|
//
|
|||
|
|
if (RawData.CompareArrays(gifData, 0, GIF87A, 0, GIF87A.Length)) {
|
|||
|
|
FileVer = FileVersion.Gif87a;
|
|||
|
|
} else if (RawData.CompareArrays(gifData, 0, GIF89A, 0, GIF87A.Length)) {
|
|||
|
|
FileVer = FileVersion.Gif89a;
|
|||
|
|
} else {
|
|||
|
|
Debug.WriteLine("GIF signature not found");
|
|||
|
|
return false;
|
|||
|
|
}
|
|||
|
|
//Debug.WriteLine("GIF: found signature " + FileVer);
|
|||
|
|
|
|||
|
|
byte pak;
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Logical screen descriptor.
|
|||
|
|
//
|
|||
|
|
int offset = GIF87A.Length;
|
|||
|
|
LogicalScreenWidth = RawData.FetchLittleUshort(gifData, ref offset);
|
|||
|
|
LogicalScreenHeight = RawData.FetchLittleUshort(gifData, ref offset);
|
|||
|
|
pak = gifData[offset++];
|
|||
|
|
GlobalColorTableFlag = (pak & 0x80) != 0;
|
|||
|
|
ColorResolution = (byte)((pak >> 4) & 0x07);
|
|||
|
|
SortFlag = (pak & 0x08) != 0;
|
|||
|
|
GlobalColorTableSize = (byte)(pak & 0x07);
|
|||
|
|
BackgroundColorIndex = gifData[offset++];
|
|||
|
|
PixelAspectRatio = gifData[offset++];
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Global color table.
|
|||
|
|
//
|
|||
|
|
if (GlobalColorTableFlag) {
|
|||
|
|
// Size is expressed as a power of 2. TableSize=7 is 256 entries, 3 bytes each.
|
|||
|
|
int tableLen = 1 << (GlobalColorTableSize + 1);
|
|||
|
|
GlobalColorTable = new byte[tableLen * 3];
|
|||
|
|
for (int i = 0; i < tableLen * 3; i++) {
|
|||
|
|
GlobalColorTable[i] = gifData[offset++];
|
|||
|
|
}
|
|||
|
|
} else {
|
|||
|
|
GlobalColorTable = new byte[0];
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
//
|
|||
|
|
// Various blocks follow. Continue until EOF is reached.
|
|||
|
|
//
|
|||
|
|
GraphicControlExtension lastGce = null;
|
|||
|
|
while (true) {
|
|||
|
|
if (offset >= gifData.Length) {
|
|||
|
|
Debug.WriteLine("Error: GIF unpacker ran off end of buffer");
|
|||
|
|
return false;
|
|||
|
|
}
|
|||
|
|
if (gifData[offset] == GIF_TRAILER) {
|
|||
|
|
break;
|
|||
|
|
} else if (gifData[offset] == EXTENSION_INTRODUCER) {
|
|||
|
|
if (gifData[offset + 1] == GRAPHIC_CONTROL_LABEL) {
|
|||
|
|
lastGce = GraphicControlExtension.Create(gifData, ref offset);
|
|||
|
|
} else {
|
|||
|
|
Debug.WriteLine("Skipping unknown extension 0x" +
|
|||
|
|
gifData[offset + 1].ToString("x2"));
|
|||
|
|
offset += 2;
|
|||
|
|
while (gifData[offset] != 0) {
|
|||
|
|
offset += gifData[offset] + 1;
|
|||
|
|
}
|
|||
|
|
offset++;
|
|||
|
|
}
|
|||
|
|
} else if (gifData[offset] == IMAGE_SEPARATOR) {
|
|||
|
|
GraphicRenderingBlock grb = GraphicRenderingBlock.Create(gifData, ref offset);
|
|||
|
|
if (grb != null) {
|
|||
|
|
if (lastGce != null) {
|
|||
|
|
grb.GraphicControlExt = lastGce;
|
|||
|
|
}
|
|||
|
|
ImageBlocks.Add(grb);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// this resets after the image
|
|||
|
|
lastGce = null;
|
|||
|
|
} else {
|
|||
|
|
Debug.WriteLine("Found unknown block start 0x" +
|
|||
|
|
gifData[offset].ToString("x2"));
|
|||
|
|
return false;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return true;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
public void DebugDump() {
|
|||
|
|
Debug.WriteLine("UnpackedGif: " + FileVer);
|
|||
|
|
Debug.WriteLine(" Logical size: " + LogicalScreenWidth + "x" + LogicalScreenHeight);
|
|||
|
|
Debug.WriteLine(" Global CT: " + GlobalColorTableFlag +
|
|||
|
|
" size=" + GlobalColorTableSize + " bkci=" + BackgroundColorIndex +
|
|||
|
|
" sort=" + SortFlag);
|
|||
|
|
Debug.WriteLine(" Aspect=" + PixelAspectRatio);
|
|||
|
|
Debug.WriteLine(" Images (" + ImageBlocks.Count + "):");
|
|||
|
|
foreach (GraphicRenderingBlock grb in ImageBlocks) {
|
|||
|
|
if (grb.GraphicControlExt != null) {
|
|||
|
|
GraphicControlExtension gce = grb.GraphicControlExt;
|
|||
|
|
Debug.WriteLine(" GCE: trans=" + gce.TransparencyFlag +
|
|||
|
|
" color=" + gce.TransparentColorIndex + " delay=" + gce.DelayTime +
|
|||
|
|
" disp=" + gce.DisposalMethod);
|
|||
|
|
} else {
|
|||
|
|
Debug.WriteLine(" No GCE");
|
|||
|
|
}
|
|||
|
|
Debug.WriteLine(" left=" + grb.ImageLeftPosition +
|
|||
|
|
" top=" + grb.ImageTopPosition + " width=" + grb.ImageWidth +
|
|||
|
|
" height=" + grb.ImageHeight);
|
|||
|
|
Debug.WriteLine(" localCT=" + grb.LocalColorTableFlag + " size=" +
|
|||
|
|
grb.LocalColorTableSize + " itrl=" + grb.InterlaceFlag);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|