/* Some PCX constants */
#define PCX_MAGIC_ID 0x0A
+#define PCX_MAX_PLANES 4
/* A raw PCX header is just a block of bytes */
typedef unsigned char RawPCXHeader[128];
/* Structured PCX header */
typedef struct PCXHeader PCXHeader;
struct PCXHeader {
- unsigned Id;
- unsigned FileVersion;
- unsigned Compressed;
- unsigned BPP;
- unsigned XMin;
- unsigned YMin;
- unsigned XMax;
- unsigned YMax;
- unsigned XDPI;
- unsigned YDPI;
- unsigned Planes;
- unsigned BytesPerPlane;
- unsigned PalInfo;
- unsigned ScreenWidth;
- unsigned ScreenHeight;
+ unsigned Id;
+ unsigned FileVersion;
+ unsigned Compressed;
+ unsigned BPP;
+ unsigned XMin;
+ unsigned YMin;
+ unsigned XMax;
+ unsigned YMax;
+ unsigned XDPI;
+ unsigned YDPI;
+ unsigned Planes;
+ unsigned BytesPerPlane;
+ unsigned PalInfo;
+ unsigned ScreenWidth;
+ unsigned ScreenHeight;
/* Calculated data */
- unsigned Width;
- unsigned Height;
+ unsigned Width;
+ unsigned Height;
};
/* Read a little endian word from a byte array at offset O */
Error ("Unsupported compression (%d) in PCX file `%s'",
P->Compressed, Name);
}
- if (P->BPP != 1 && P->BPP != 4 && P->BPP != 8) {
- Error ("Unsupported bit depth (%u) in PCX file `%s'",
- P->BPP, Name);
+ /* We support:
+ * - one plane with either 1 or 8 bits per pixel
+ * - three planes with 8 bits per pixel
+ * - four planes with 8 bits per pixel (does this exist?)
+ */
+ if (!((P->BPP == 1 && P->Planes == 1) ||
+ (P->BPP == 8 && (P->Planes == 1 || P->Planes == 3 || P->Planes == 4)))) {
+ /* We could support others, but currently we don't */
+ Error ("Unsupported PCX format: %u planes, %u bpp in PCX file `%s'",
+ P->Planes, P->BPP, Name);
}
if (P->PalInfo != 1 && P->PalInfo != 2) {
Error ("Unsupported palette info (%u) in PCX file `%s'",
static void DumpPCXHeader (const PCXHeader* P, const char* Name)
/* Dump the header of the PCX file in readable form to stdout */
{
- printf ("File name: %s\n", Name);
- printf ("PCX Version: ");
+ printf ("File name: %s\n", Name);
+ printf ("PCX Version: ");
switch (P->FileVersion) {
case 0: puts ("2.5"); break;
case 2: puts ("2.8 with palette"); break;
case 4: puts ("PCX for Windows without palette"); break;
case 5: puts ("3.0"); break;
}
- printf ("Image type: %s\n", P->PalInfo? "color" : "grayscale");
- printf ("Compression: %s\n", P->Compressed? "RLE" : "None");
- printf ("Structure: %u planes of %u bits\n", P->Planes, P->BPP);
- printf ("Bounding box: [%u/%u - %u/%u]\n", P->XMin, P->YMin, P->XMax, P->YMax);
- printf ("Resolution: %u/%u DPI\n", P->XDPI, P->YDPI);
- printf ("Screen size: %u/%u\n", P->ScreenWidth, P->ScreenHeight);
+ printf ("Image type: %s\n", P->PalInfo? "color" : "grayscale");
+ printf ("Compression: %s\n", P->Compressed? "RLE" : "None");
+ printf ("Structure: %u planes of %u bits\n", P->Planes, P->BPP);
+ printf ("Bounding box: [%u/%u - %u/%u]\n", P->XMin, P->YMin, P->XMax, P->YMax);
+ printf ("Resolution: %u/%u DPI\n", P->XDPI, P->YDPI);
+ printf ("Screen size: %u/%u\n", P->ScreenWidth, P->ScreenHeight);
+ printf ("Bytes per plane: %u\n", P->BytesPerPlane);
+}
+
+
+
+static void ReadPlane (FILE* F, PCXHeader* P, unsigned char* L)
+/* Read one (possibly compressed) plane from the file */
+{
+ if (P->Compressed) {
+
+ /* Uncompress RLE data */
+ unsigned Remaining = P->Width;
+ while (Remaining) {
+
+ unsigned char C;
+
+ /* Read the next byte */
+ unsigned char B = Read8 (F);
+
+ /* Check for a run length */
+ if ((B & 0xC0) == 0xC0) {
+ C = (B & 0x3F); /* Count */
+ B = Read8 (F); /* Value */
+ } else {
+ C = 1;
+ }
+
+ /* Write the data to the buffer */
+ if (C > Remaining) {
+ C = Remaining;
+ }
+ memset (L, B, C);
+
+ /* Bump counters */
+ L += C;
+ Remaining -= C;
+
+ }
+ } else {
+
+ /* Just read one line */
+ ReadData (F, L, P->Width);
+
+ }
}
{
PCXHeader* P;
Bitmap* B;
+ unsigned char* L;
+ Pixel* Px;
+ unsigned X, Y;
+
+
/* Open the file */
FILE* F = fopen (Name, "rb");
DumpPCXHeader (P, Name);
}
+ /* Create the bitmap */
+ B = NewBitmap (P->Width, P->Height);
+
+ /* Determine the type of the bitmap */
+ switch (P->Planes) {
+ case 1: B->Type = (P->PalInfo? bmIndexed : bmMonochrome); break;
+ case 3: B->Type = bmRGB; break;
+ case 4: B->Type = bmRGBA; break;
+ default:Internal ("Unexpected number of planes");
+ }
+
+ /* Remember the PCX header in the tag */
+ B->Tag = P;
+
+ /* Allocate memory for the scan line */
+ L = xmalloc (P->Width);
+
+ /* Read the pixel data */
+ Px = B->Data;
+ if (P->Planes == 1) {
+
+ /* This is either monochrome or indexed */
+ if (P->BPP == 1) {
+ /* Monochrome */
+ for (Y = 0, Px = B->Data; Y < P->Height; ++Y) {
+
+ unsigned I;
+ unsigned char Mask;
+
+ /* Read the plane */
+ ReadPlane (F, P, L);
+
+ /* Create pixels */
+ for (X = 0, I = 0, Mask = 0x01; X < P->Width; ++Px) {
+ Px->Index = (L[I] & Mask) != 0;
+ if (Mask == 0x80) {
+ Mask = 0x01;
+ ++I;
+ } else {
+ Mask <<= 1;
+ }
+ }
+
+ }
+ } else {
+ /* One plane with 8bpp is indexed */
+ for (Y = 0, Px = B->Data; Y < P->Height; ++Y) {
+
+ /* Read the plane */
+ ReadPlane (F, P, L);
+
+ /* Create pixels */
+ for (X = 0; X < P->Width; ++X, ++Px) {
+ Px->Index = L[X];
+ }
+ }
+ }
+ } else {
+ /* 3 or 4 planes are RGB or RGBA (don't know if this exists) */
+ for (Y = 0, Px = B->Data; Y < P->Height; ++Y) {
+
+ /* Read the R plane and move the data */
+ ReadPlane (F, P, L);
+ for (X = 0; X < P->Width; ++X, ++Px) {
+ Px->C.R = L[X];
+ }
+
+ /* Read the G plane and move the data */
+ ReadPlane (F, P, L);
+ for (X = 0; X < P->Width; ++X, ++Px) {
+ Px->C.G = L[X];
+ }
+
+ /* Read the B plane and move the data */
+ ReadPlane (F, P, L);
+ for (X = 0; X < P->Width; ++X, ++Px) {
+ Px->C.B = L[X];
+ }
+
+ /* Either read the A plane or clear it */
+ if (P->Planes == 4) {
+ ReadPlane (F, P, L);
+ for (X = 0; X < P->Width; ++X, ++Px) {
+ Px->C.A = L[X];
+ }
+ } else {
+ for (X = 0; X < P->Width; ++X, ++Px) {
+ Px->C.A = 0;
+ }
+ }
+ }
+ }
+
+ /* One plane means we have a palette which is either part of the header
+ * or follows.
+ */
+ if (B->Type == bmMonochrome) {
+
+ /* Create the monochrome palette */
+ B->Pal = NewMonochromePalette ();
+
+ } else if (B->Type == bmIndexed) {
+
+ unsigned Count;
+ unsigned I;
+ unsigned char Palette[256][3];
+ unsigned long EndPos;
+
+ /* Determine the current file position */
+ unsigned long CurPos = FileGetPos (F);
+
+ /* Seek to the end of the file */
+ (void) fseek (F, 0, SEEK_END);
+
+ /* Get this position */
+ EndPos = FileGetPos (F);
+
+ /* There's a palette if the old location is 769 bytes from the end */
+ if (EndPos - CurPos == sizeof (Palette) + 1) {
+
+ /* Seek back */
+ FileSetPos (F, CurPos);
+
+ /* Check for palette marker */
+ if (Read8 (F) != 0x0C) {
+ Error ("Invalid palette marker in PCX file `%s'", Name);
+ }
+
+ /* Read the palette */
+ ReadData (F, Palette, sizeof (Palette));
+ Count = 256;
+
+ } else if (EndPos == CurPos) {
+
+ /* The palette is in the header */
+ FileSetPos (F, 16);
+ ReadData (F, Palette, 48);
+ Count = 16;
+
+ } else {
+ Error ("Error in PCX file `%s': %lu bytes at end of pixel data",
+ Name, EndPos - CurPos);
+ }
+
+ /* Create the palette from the data */
+ B->Pal = NewPalette (Count);
+ for (I = 0; I < Count; ++I) {
+ B->Pal->Entries[I].R = Palette[I][0];
+ B->Pal->Entries[I].G = Palette[I][1];
+ B->Pal->Entries[I].B = Palette[I][2];
+ B->Pal->Entries[I].A = 0;
+ }
+ }
+
/* Close the file */
fclose (F);
projects / cc65 / blobdiff