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MaximDudeMaximDude
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Get indexed png writer somewhat working - output is spaghetti but at least it's a valid file now
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3 files changed

+93
-20
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3 files changed

+93
-20
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‎types/FileIO.bmx

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Original file line numberDiff line numberDiff line change
@@ -1,4 +1,3 @@
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Import BRL.PNGLoader
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Import "IndexedImageWriter.bmx"
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'//// FILE IO ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

‎types/IndexedImageWriter.bmx

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Original file line numberDiff line numberDiff line change
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Import BRL.Bank
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Import "Utility.bmx"
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Import "UtilityPNG.bmx"
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'//// INDEXED IMAGE WRITER //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Struct RGBColor
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Field m_R:Byte
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Field m_G:Byte
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Field m_B:Byte
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EndStruct
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Type IndexedImageWriter
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Field m_PalR:Byte[256]
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Field m_PalG:Byte[256]
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Field m_PalB:Byte[256]
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Field m_CRCTable:Int[256]
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Field m_Palette:RGBColor[256]
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'Field m_CRCTable:Int[256]
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Method New()
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LoadDefaultPalette()
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Rem
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'Initialize CRC table
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For Local i:Int = 0 To 255
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Local value:Int = i
@@ -26,18 +37,19 @@ Type IndexedImageWriter
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Next
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m_CRCTable[i] = value
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Next
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EndRem
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EndMethod
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Rem
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Method GenerateCRC32FromBank:Int(bank:TBank)
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Local crcResult:Int = $FFFFFFFF
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For Local i:Int = 0 Until BankSize(bank)
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crcResult = (crcResult Shr 8) ~ m_CRCTable[PeekByte(bank, i) ~ (crcResult & $FF)]
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Next
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Return ~crcResult '~ for bitwise complement
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EndMethod
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EndRem
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Method LoadDefaultPalette()
@@ -50,6 +62,10 @@ Type IndexedImageWriter
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m_PalR[index] = ReadByte(paletteStream)
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m_PalG[index] = ReadByte(paletteStream)
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m_PalB[index] = ReadByte(paletteStream)
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m_Palette[index].m_R = m_PalR[index]
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m_Palette[index].m_G = m_PalG[index]
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m_Palette[index].m_B = m_PalB[index]
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Next
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CloseStream(paletteStream)
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EndMethod
@@ -147,7 +163,7 @@ Type IndexedImageWriter
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EndMethod
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Rem
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Method WriteIndexedPNGFromPixmap:Int(sourcePixmap:TPixmap, filename:String)
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If filename = Null Then
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Return False
@@ -176,15 +192,13 @@ Type IndexedImageWriter
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WriteInt(outputStream, pngWidth) 'Image Width (4 bytes)
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WriteInt(outputStream, pngHeight) 'Image Height (4 bytes)
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WriteByte(outputStream, 4) 'Bit Depth (1 byte) - BYTES per pixel not BITS per pixel
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WriteByte(outputStream, 8) 'Bit Depth (1 byte)
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WriteByte(outputStream, 3) 'Color Type (1 byte) - 3 for indexed color
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WriteByte(outputStream, 0) 'Compression Method (1 byte)
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WriteByte(outputStream, 0) 'Filter Method (1 byte)
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WriteByte(outputStream, 0) 'Interlace Method (1 byte) - 0 for no interlace
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Rem
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Figure out how to generate correct CRC
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EndRem
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'Figure out how to generate correct CRC
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WriteInt(outputStream, 0) 'CRC-32 checksum (4 bytes)
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'PLTE chunk (color table)
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WriteByte(outputStream, m_PalR[index]) 'Red (1 byte)
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Next
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Rem
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Figure out how to generate correct CRC
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EndRem
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'Figure out how to generate correct CRC
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WriteInt(outputStream, 0) 'CRC-32 checksum (4 bytes)
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'IDAT chunk (pixel array)
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Next
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Next
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Rem
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Figure out how to generate correct CRC
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EndRem
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'Figure out how to generate correct CRC
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WriteInt(outputStream, 0) 'CRC-32 checksum (4 bytes)
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'IEND chunk (EOF)
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WriteInt(outputStream, 0) 'Chunk Length (4 bytes) - 0 for IEND
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WriteInt(outputStream, 1229278788) 'Chunk Type (4 bytes) - 1229278788 (decimal) or 49 45 4E 44 (hex) or IEND (ascii)
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Rem
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Figure out how to generate correct CRC
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EndRem
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'Figure out how to generate correct CRC
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WriteInt(outputStream, 0) 'CRC-32 checksum (4 bytes)
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CloseStream(outputStream)
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Return True
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EndIf
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EndMethod
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EndRem
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Method WriteIndexedPNGFromPixmap:Int(sourcePixmap:TPixmap, filename:String, compression:Int = 5)
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Local outputStream:TStream = WriteStream(filename)
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Try
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Local pngPtr:Byte Ptr = png_create_write_struct("1.6.37", Null, Null, Null)
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Local pngInfoPtr:Byte Ptr = png_create_info_struct(pngPtr)
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png_set_write_fn(pngPtr, outputStream, UtilityPNG.PNGWrite, UtilityPNG.PNGFlush)
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png_set_compression_level(pngPtr, Utility.Clamp(compression, 0, 9))
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png_set_IHDR(pngPtr, pngInfoPtr, sourcePixmap.Width, sourcePixmap.Height, 8, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT)
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Local palettePtr:Byte Ptr = m_Palette
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png_set_PLTE(pngPtr, pngInfoPtr, palettePtr, 256);
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'sourcePixmap = sourcePixmap.Convert(PF_I8)
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For Local pixelY:Int = 0 Until sourcePixmap.Height
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For Local pixelX:Int = 0 Until sourcePixmap.Width
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WritePixel(sourcePixmap, pixelX, pixelY, ConvertColorToClosestIndex(ReadPixel(sourcePixmap, pixelX, pixelY)))
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Next
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Next
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Local rows:Byte Ptr[sourcePixmap.Height]
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For Local i = 0 Until sourcePixmap.Height
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rows[i] = sourcePixmap.PixelPtr(0, i)
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Next
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png_set_rows(pngPtr, pngInfoPtr, rows)
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png_write_png(pngPtr, pngInfoPtr, 0, Null)
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png_destroy_write_struct(Varptr pngPtr, Varptr pngInfoPtr, Null)
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CloseStream(outputStream)
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Return True
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Catch error:String
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If error <> "PNG ERROR" Throw error
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EndTry
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EndMethod
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EndType

‎types/UtilityPNG.bmx

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Import PUB.LibPNG
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'//// PNG UTILITY FUNCTIONS /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Type UtilityPNG
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Function PNGWrite(pngPtr:Byte Ptr, buf:Byte Ptr, size:Int)
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Local outputStream:TStream = TStream(png_get_io_ptr(pngPtr))
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Return outputStream.WriteBytes(buf, size)
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EndFunction
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Function PNGFlush(pngPtr:Byte Ptr)
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Local outputStream:TStream = TStream(png_get_io_ptr(pngPtr))
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FlushStream(outputStream)
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EndFunction
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EndType
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'////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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Extern
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Function png_set_PLTE(png_ptr:Byte Ptr, info_ptr:Byte Ptr, palette:Byte Ptr, num_palette:Int) = "bmx_png_set_PLTE"
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EndExtern

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