/* Rendition.c by Martin Boyd 25-Apr-93. * * An example file loader using the OpalVision LSI interface. * * The rendition file format simply consists of a 1024 byte * header (Described below) followed by 32 bit (RGBA) image data * compressed using run-length encoding. Each run is encoded as * 6 bytes: * * Byte 0 - Red * Byte 1 - Green * Byte 2 - Blue * Byte 3 - Alpha * Byte 4 - Run length low byte * Byte 5 - Run length high byte * * NOTE: This loader only loads the 6RN format as described * above. */ #include #include #include #include #include #include #include #include #include #include char Version[] = "\0$VER: Rendition.Loader 1.0 (25.04.93)"; /* Rendition format information */ struct Tile { long Ptr; long Length; }; struct RendHeader /* 1024 byte header */ { long Magic; /* H_MAGIC */ SHORT Version; /* 2 */ char Label[128]; /* ASCII Desciption */ char Date[26]; /* Date of image creation */ SHORT Height; /* Pixel height of image */ SHORT Width; /* Pixel width of image */ SHORT TileHeight; /* Pixel height of tile */ SHORT TileWidth; /* Pixel width of tile */ SHORT Format; /* See below */ SHORT Encoding; /* See below */ long NumRuns; /* Number of runs */ SHORT BlockSize; /* 1024 */ SHORT XOffset; /* Horizontal offset */ SHORT YOffset; /* Vertical offset */ long CMapLen; /* Number of colour table entries */ long CMapPtr; /* Pointer to ColourMap */ char CMapName[64]; /* Colour Map filename */ struct Tile Tile[64]; /* Tile pointer table */ char UnSpec[258]; /* Unspecified (reserved) */ }; #define H_MAGIC 0xE880 #define H_BLOCKSIZE 1024 #define H_HEADERSIZE 1024 /* Format types */ #define H_CRGBAPIX 2 /* 4 bytes per pixel */ #define H_6RUNLH 11 /* 6 bytes per run */ #define H_2RUN 12 /* 2 bytes per run; colour map in seperate file */ #define H_2RUNMAP 13 /* 2 bytes per run; colour map in image file */ #define H_COLOURMAP 20 /* 4 bytes per entry */ #define H_MIPMAP 22 /* Mip map: header, map table and 4-byte pixels */ #define H_ONEDRGBA8 23 /* 1D table of 4-byte pixels */ #define H_ONEDBYTE 24 /* 1D table of bytes */ char LoaderName[] = "Rendition"; char PortName[] = "Rendition_Loader"; int Width,Height; /* Dimension of the image being loaded */ BPTR File; /* File handle of image being loaded */ ULONG LoadFlags; /* Flags from the OVCMD_LOADIMAGE command */ struct MsgPort *LoadPort; /* This modules message port */ struct OpalBase *OpalBase; BOOL Do_Load (void); void main (void) { struct LSIMessage *Mesg; struct RendHeader *Header; LoadPort = CreatePort (PortName,0); if (LoadPort==NULL) exit (10); OpalBase = (struct OpalBase *)OpenLibrary ("opal.library",0); if (OpalBase==NULL) { DeletePort (LoadPort); exit (10); } if (!AddOVLoader (LoaderName,LoadPort, OVLF_ALLOWIMAGE|OVLF_ALLOWALPHA|OVLF_NEEDFILENAME)) { DeletePort (LoadPort); CloseLibrary ((struct Library *)OpalBase); exit (10); } CloseLibrary ((struct Library *)OpalBase); /* library must be closed */ OpalBase = NULL; while (1) { WaitPort (LoadPort); while (Mesg = (struct LSIMessage *)GetMsg (LoadPort)) { switch (Mesg->lsi_Type) { case OVCMD_LOADIMAGE: File = Mesg->lsi_File; LoadFlags = Mesg->lsi_Flags; ReplyMsg ((struct Message *)Mesg); Do_Load(); break; case OVCMD_EXPUNGE: if (!OpalBase) OpalBase = (struct OpalBase *) OpenLibrary ("opal.library",0); RemOVLoader (LoaderName); if (OpalBase) CloseLibrary ((struct Library *)OpalBase); DeletePort (LoadPort); ReplyMsg ((struct Message *)Mesg); exit (0); break; case OVCMD_FORMATCHECK: Header = (struct RendHeader *)Mesg->lsi_Address; if ((Header->Magic!=H_MAGIC) || (Header->Format!=H_6RUNLH)) Mesg->lsi_Result = FALSE; else { Width = Header->Width; Height = Header->Height; Mesg->lsi_Result = TRUE; Mesg->lsi_Width = Width; Mesg->lsi_Height = Height; Mesg->lsi_Depth = 24; Mesg->lsi_Flags = LSIF_HASIMAGE|LSIF_HASALPHA; } ReplyMsg ((struct Message *)Mesg); break; } } } } BOOL Do_Load (void) { int x,y; struct MsgPort *HostPort; struct LSIMessage Mesg; UBYTE *RBuff,*GBuff,*BBuff,*ABuff,*DestBuff,*SrcBuff; register UBYTE *Src,*R,*G,*B,*A,RData,GData,BData,AData; long SBuffSize,DBuffSize,FileLength,RunLength,AmountLeft; long AmountRead,FilePos; int DBuffRows,Row; HostPort = FindPort (OVLOADERPORT); /* Find the host port */ if (HostPort==NULL) return (FALSE); memset (&Mesg,0,sizeof(struct LSIMessage)); Mesg.lsi_Node.mn_Node.ln_Type = NT_MESSAGE; Mesg.lsi_Node.mn_ReplyPort = LoadPort; Mesg.lsi_Node.mn_Length = sizeof (struct LSIMessage); /* This buffer is used to hold the decompressed data */ DBuffRows = 20; do { DBuffSize = DBuffRows * Width * 4; DestBuff = AllocMem (DBuffSize,MEMF_CLEAR); if (DestBuff==NULL) DBuffRows--; } while ((DestBuff==NULL) && (DBuffRows>0)); if (DBuffRows==0) { Mesg.lsi_Type = OVCMD_ERROR; Mesg.lsi_Result = LSI_ERR_OUTOFMEM; LSICmd (HostPort,LoadPort,&Mesg); return (FALSE); } RBuff = DestBuff; GBuff = DestBuff+(1*DBuffRows*Width); BBuff = DestBuff+(2*DBuffRows*Width); ABuff = DestBuff+(3*DBuffRows*Width); /* Allocate a buffer for raw file data. * Allocate the biggest buffer we can, start * with the size of the file and work our way down. */ Seek (File,0,OFFSET_END); FileLength = Seek (File,sizeof(struct RendHeader),OFFSET_BEGINNING); SBuffSize = FileLength - sizeof (struct RendHeader); do { SrcBuff = AllocMem (SBuffSize,MEMF_CLEAR); if (SrcBuff==NULL) SBuffSize = SBuffSize/2; } while ((SrcBuff==NULL) && (SBuffSize>(DBuffSize+1024))); if (SrcBuff==NULL) { FreeMem (DestBuff,DBuffSize); Mesg.lsi_Type = OVCMD_ERROR; Mesg.lsi_Result = LSI_ERR_OUTOFMEM; LSICmd (HostPort,LoadPort,&Mesg); return (FALSE); } /* Read in Image data and get the first run */ FilePos = Seek (File,0,OFFSET_CURRENT); AmountRead = Read (File,SrcBuff,SBuffSize); AmountLeft = AmountRead; R = RBuff; G = GBuff; B = BBuff; A = ABuff; Src = SrcBuff; RData = *Src++; GData = *Src++; BData = *Src++; AData = *Src++; RunLength = *Src++; RunLength += (*Src++)<<8; Row = 0; AmountLeft -=6; for (y=0; y