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milance

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Reading BMP and PCX

Can someone send me a code in Turbo PASCAL 6.0 for reading and drawing pictures in BMP and PCX format, with resolution 640X480, and 256 colour?
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omsec

I've actually have loaders for 320x200x256 with sources. I will see if I can find something in your desired mode ;)
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Bernard_Lee

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{ This is my first answer to Experts-Exchange(I'm New)
  By Raid

BMP File Loader: (256 color)
 There is 3 parts to a BMP.
  1st Part: Header
  2nd Part: Color Declaration
  3rd Part: Graphic }

Uses
 Crt, graph;

Type
 ColorType = Record
  Blue: Byte;
  Green: Byte;
  Red: Byte;
  Reserved: Byte;
 End;

Procedure LoadBMP(FileName: String);
Var
 Color: Byte;
 LoopVar: Byte;
 ReadVar: Byte;
 BitsPerPlane: Word;
 BitsPerPixel: Word;
 LoopX: Word;
 LoopY: Word;
 BMPSizeX: Longint;
 BMPSizeY: Longint;
 BitCompression: Longint;
 ColorsUsed: Longint;
 ColorsImportant: Longint;
 ImageSize: Longint;
 ResX: Longint;
 ResY: Longint;
 Colors: array[0 .. 255] of ColorType;
 FileVar: File;
Begin
 assign(FileVar, FileName); reset(FileVar, 1); { Open BMP }
 { Now, lets load the header(1st Part) }
 { The first 18 bytes in the file }
 { have nothing to do with the graphic }
 for LoopVar := 1 to 18 do blockread(FileVar, ReadVar, 1);
 { Read The next 4 Bytes(Longint) which is the width of the BMP }
 blockread(FileVar, BMPSizeX, 4);

 { Read The next 4 Bytes(Longint) which is the length of the BMP }
 blockread(FileVar, BMPSizeY, 4);

 { Read The next 2 Bytes(Word) for the number of Bits per plane }
 blockread(FileVar, BitsPerPlane, 2);

 { Read The next 2 Bytes(Word) for the number of Bits per pixel }
 { Bits per pixel example }
 { Lets say the value is 8, that means 8 Bits per pixel, in other }
 { words that means 256 Colors }
 { 8-Bits is a Byte(256 Values) }
 { 16-Bits is a Word(65536 Values) }
 { 24-Bits is a Lonting(-2 Million to 2 Million, Roughly) }
 blockread(FileVar, BitsPerPixel, 2);

 { Next, we read the bit compression Value, which is 4 Bytes(Longint) }
 { Don't worry about this, because most BMPS don't have bit compression }
 blockread(FileVar, BitCompression, 4);

 { The next 4 Bytes(Longint) is the size of the BMP Graphic }
 { Size of Graphic should be BMPSizeX * BMPSizeY }
 blockread(FileVar, ImageSize, 4);

 { The next 4 Bytes(Longint) is the resolution width }
 { Don't worry about this, because it has to do with windows }
 { I presume. }
 blockread(FileVar, ResX, 4);

 { And the next 4 Bytes(Longint) is the resolution length }
 { also don't worry about it }
 blockread(FileVar, ResY, 4);

 { The next 4 Bytes(Longint) is how many colors there are used }
 { in the BMP. }
 blockread(FileVar, ColorsUsed, 4);

 { And the Next 4 Bytes(Longint) is how many colors are important }
 { This is the value that you are looking for of how many colors }
 { There are in the BMP }
 blockread(FileVar, ColorsImportant, 4);

 { -Phew- done loading the Header.  Now lets go on to loading the colors }
 { which is the 2nd Part }
 { The colors are saved like this: }
 { Color 0:        }
 {  Blue(Byte)     }
 {  Green(Byte)    }
 {  Red(Byte)      }  
 {  Reserved(Byte) }
 { Color 1:        }
 {  Blue(Byte)     }
 {  Green(Byte)    }
 {  Red(Byte)      }  
 {  Reserved(Byte) }
 { Color 2:        }
 {  Blue(Byte)     }
 {  Green(Byte)    }
 {  Red(Byte)      }  
 {  Reserved(Byte) }
 { etc. }
 { Load Colors into Variable }
 for LoopVar := 0 to ColorsImportant - 1 do begin
  blockread(FileVar, Colors[LoopVar], SizeOf(ColorType));
 end;
 { To Palette the Colors Quickly, do this }
 port[$3c8] := 0; { Start at color 0 }
 for LoopVar := 0 to ColorsImportant - 1 do begin
  port[$3c9] := Colors[LoopVar].Red;
  port[$3c9] := Colors[LoopVar].Green;
  port[$3c9] := Colors[LoopVar].Blue;
 end;
 { or you could set the palette using SetRGBPalette }
 { eep! }

 { Then, (Finally) we load the 3rd part, which is the graphic }
 { The graphic is saved funny, I don't know why the people who }
 { designed the BMP saved from left-right, down-up.  Instead of }
 { left-right, up-down.  I guess they wanted to be different }
 { Ok, lets draw it }

 for LoopY := BMPSizeY downto 1 do begin
  for LoopX := 1 to BMPSizeX do begin
   blockread(FileVar, Color, 1);
   putpixel(LoopX - 1, LoopY - 1, Color);
  end;
 end;

 close(FileVar); { Close BMP }

 { If you have any questions, contact RAID }
End;




{ Sorry Miliance, The one above was not tested
  and it does not work }
{ So here is the working version }
{ You will have to set the screen mode yourself though }
{ If you want a program and a driver of 256 colors (.BGI) }
{ I can give you one. }

{BMP File Loader: (256 color)
 There is 3 parts to a BMP.
  1st Part: Header
  2nd Part: Color Declaration
  3rd Part: Graphic }

Uses
 Crt, graph;

Type
 ColorType = Record
  Blue: Byte;
  Green: Byte;
  Red: Byte;
  Reserved: Byte;
 End;

Procedure LoadBMP(FileName: String);
Var
 Color: Byte;
 LoopVar: Word;
 ReadVar: Byte;
 BitsPerPlane: Word;
 BitsPerPixel: Word;
 LoopX: Word;
 LoopY: Word;
 BMPSizeX: Longint;
 BMPSizeY: Longint;
 BitCompression: Longint;
 ColorsUsed: Longint;
 ColorsImportant: Longint;
 ImageSize: Longint;
 ResX: Longint;
 ResY: Longint;
 Colors: array[0 .. 255] of ColorType;
 FileVar: File;
Begin
 assign(FileVar, FileName); reset(FileVar, 1); { Open BMP }
 { Now, lets load the header(1st Part) }
 { The first 18 bytes in the file }
 { have nothing to do with the graphic }
 for LoopVar := 1 to 18 do blockread(FileVar, ReadVar, 1);
 { Read The next 4 Bytes(Longint) which is the width of the BMP }
 blockread(FileVar, BMPSizeX, 4);

 { Read The next 4 Bytes(Longint) which is the length of the BMP }
 blockread(FileVar, BMPSizeY, 4);

 { Read The next 2 Bytes(Word) for the number of Bits per plane }
 blockread(FileVar, BitsPerPlane, 2);

 { Read The next 2 Bytes(Word) for the number of Bits per pixel }
 { Bits per pixel example }
 { Lets say the value is 8, that means 8 Bits per pixel, in other }
 { words that means 256 Colors }
 { 8-Bits is a Byte(256 Values) }
 { 16-Bits is a Word(65536 Values) }
 { 24-Bits is a Lonting(-2 Million to 2 Million, Roughly) }
 blockread(FileVar, BitsPerPixel, 2);

 { Next, we read the bit compression Value, which is 4 Bytes(Longint) }
 { Don't worry about this, because most BMPS don't have bit compression }
 blockread(FileVar, BitCompression, 4);

 { The next 4 Bytes(Longint) is the size of the BMP Graphic }
 { Size of Graphic should be BMPSizeX * BMPSizeY }
 blockread(FileVar, ImageSize, 4);

 { The next 4 Bytes(Longint) is the resolution width }
 { Don't worry about this, because it has to do with windows }
 { I presume. }
 blockread(FileVar, ResX, 4);

 { And the next 4 Bytes(Longint) is the resolution length }
 { also don't worry about it }
 blockread(FileVar, ResY, 4);

 { The next 4 Bytes(Longint) is how many colors there are used }
 { in the BMP. }
 blockread(FileVar, ColorsUsed, 4);

 { And the Next 4 Bytes(Longint) is how many colors are important }
 { This is the value that you are looking for of how many colors }
 { There are in the BMP }
 blockread(FileVar, ColorsImportant, 4);

 { -Phew- done loading the Header.  Now lets go on to loading the colors }
 { which is the 2nd Part }
 { The colors are saved like this: }
 { Color 0:        }
 {  Blue(Byte)     }
 {  Green(Byte)    }
 {  Red(Byte)      }  
 {  Reserved(Byte) }
 { Color 1:        }
 {  Blue(Byte)     }
 {  Green(Byte)    }
 {  Red(Byte)      }  
 {  Reserved(Byte) }
 { Color 2:        }
 {  Blue(Byte)     }
 {  Green(Byte)    }
 {  Red(Byte)      }  
 {  Reserved(Byte) }
 { etc. }
 { Load Colors into Variable }
 if ColorsImportant = 0 then ColorsImportant := 256;
 for LoopVar := 0 to ColorsImportant - 1 do begin
  blockread(FileVar, Colors[LoopVar], SizeOf(ColorType));
 end;
 { To Palette the Colors Quickly, do this }
 port[$3c8] := 0; { Start at color 0 }
 for LoopVar := 0 to ColorsImportant - 1 do begin
  port[$3c9] := Colors[LoopVar].Red div 4;
  port[$3c9] := Colors[LoopVar].Green div 4;
  port[$3c9] := Colors[LoopVar].Blue div 4;
 end;
 { or you could set the palette using SetRGBPalette }
 { eep! }

 { Then, (Finally) we load the 3rd part, which is the graphic }
 { The graphic is saved funny, I don't know why the people who }
 { designed the BMP saved from left-right, down-up.  Instead of }
 { left-right, up-down.  I guess they wanted to be different }
 { Ok, lets draw it }

 for LoopY := BMPSizeY downto 1 do begin
  for LoopX := 1 to BMPSizeX do begin
   blockread(FileVar, Color, 1);
   putpixel(LoopX - 1, LoopY - 1, Color);
  end;
 end;

 close(FileVar); { Close BMP }

 { If you have any questions, contact RAID }
End;

Begin
 { Example }
 { LoadBMP('C:\WINDOWS\CLOUDS.BMP'); }
End.