dmlib: libgfx.c comparison

comparison libgfx.c @ 447:0e27860ddcfe

Finish initial implementation of IFF ILBM loader. And whoa .. it seems to be working.

author	Matti Hamalainen <ccr@tnsp.org>
date	Sun, 04 Nov 2012 08:40:17 +0200
parents	1d65efb29986
children	f1aab48a76fe

comparison

equal deleted inserted replaced

-:a6d0e101cd16
+:0e27860ddcfe
 {
 DMIFFChunk chBMHD, chCMAP, chBODY;
 DMIFFBMHD bmhd;
 int ncolors;
 DMColor *pal;
-DMImage *img;
 BOOL paletted;
 } DMIFF;
 static BOOL dmReadIFFChunk(FILE *fp, DMIFFChunk *chunk)
 }
 static BOOL dmSkipIFFChunkRest(FILE *fp, const DMIFFChunk *chunk, const Uint32 used)
 {
 if (chunk->size > used)
+{
+dmMsg(3, "ILBM: Skipping %d bytes (%d of %d consumed)\n",
+chunk->size - used, used, chunk->size);
 return fseeko(fp, chunk->size - used, SEEK_CUR) == 0;
+}
 else
 return TRUE;
 }
 static BOOL dmCheckIFFChunk(DMIFFChunk *dest, DMIFFChunk *chunk,
 return TRUE;
 }
-int dmDecodeILBMBody(FILE *fp, DMIFF *iff)
+static BOOL dmIFFDecodeByteRun1Row(FILE *fp, Uint8 *buf, const size_t bufLen)
 {
-return DMERR_OK;
+size_t offs = 0;
+do
+{
+Sint8 dcount;
+Uint8 data;
+if (!dm_fread_byte(fp, (Uint8 *) &dcount))
+return FALSE;
+if (dcount == -128)
+{
+if (!dm_fread_byte(fp, &data))
+return FALSE;
+}
+else
+if (dcount < 0)
+{
+int count = (-dcount) + 1;
+if (!dm_fread_byte(fp, &data))
+return FALSE;
+while (count-- && offs < bufLen)
+buf[offs++] = data;
+}
+else
+{
+int count = dcount + 1;
+while (count-- && offs < bufLen)
+{
+if (!dm_fread_byte(fp, &data))
+return FALSE;
+buf[offs++] = data;
+}
+}
+} while (offs < bufLen);
+return TRUE;
+}
+static BOOL dmIFFReadOneRow(FILE *fp, DMIFF *iff, Uint8 *buf, const size_t bufLen)
+{
+if (iff->bmhd.compression == IFF_COMP_BYTERUN1)
+return dmIFFDecodeByteRun1Row(fp, buf, bufLen);
+else
+return dm_fread_str(fp, buf, bufLen);
+}
+void dmDecodeBitPlane(Uint8 *dp, Uint8 *src, const int width, const int nplane)
+{
+int xc;
+for (xc = 0; xc < width; xc++)
+{
+const Uint8 data = (src[xc / 8] >> (7 - (xc & 7))) & 1;
+dp[xc] |= (data << nplane);
+}
+}
+int dmDecodeILBMBody(FILE *fp, DMIFF *iff, DMImage **pimg, Uint32 *read)
+{
+DMImage *img;
+Uint8 *buf;
+size_t bufLen;
+int yc, res = DMERR_OK;
+*read = 0;
+// Allocate image
+if ((*pimg = img = dmImageAlloc(iff->bmhd.w, iff->bmhd.h)) == NULL)
+return DMERR_MALLOC;
+// Allocate planar decoding buffer
+bufLen = ((img->width + 15) / 16) * 2;
+if ((buf = dmMalloc(bufLen)) == NULL)
+return DMERR_MALLOC;
+dmMsg(2, "ILBM: plane row size %d bytes.\n", bufLen);
+// Decode the chunk
+for (yc = 0; yc < img->height; yc++)
+{
+int plane;
+const int nplanes = iff->bmhd.nplanes;
+Uint8 *dp = img->data + (yc * img->pitch);
+memset(dp, 0, img->pitch);
+for (plane = 0; plane < nplanes; plane++)
+{
+// Decompress or read data
+if (!dmIFFReadOneRow(fp, iff, buf, bufLen))
+{
+dmError("ILBM: Error in reading image plane #%d.\n", plane);
+res = DMERR_FREAD;
+goto error;
+}
+// Decode bitplane
+dmDecodeBitPlane(dp, buf, img->width, plane);
+*read += bufLen;
+}
+// Read mask data
+if (iff->bmhd.masking == IFF_MASK_HAS_MASK)
+{
+int xc;
+// Decompress or read data
+if (!dmIFFReadOneRow(fp, iff, buf, bufLen))
+{
+dmError("ILBM: Error in reading mask plane.\n");
+res = DMERR_FREAD;
+goto error;
+}
+// Decode mask
+for (xc = 0; xc < img->width; xc++)
+{
+const Uint8 data = (buf[xc / 8] >> (7 - (xc & 7))) & 1;
+// Black out any pixels with mask bit 0
+if (!data)
+dp[xc] = 0;
+}
+*read += bufLen;
+}
+}
+error:
+dmFree(buf);
+return res;
 }
 int dmReadILBMImageFILE(FILE *fp, DMImage **pimg)
 {
 Uint32 idILBM;
 DMIFFChunk chunk;
 DMIFF iff;
+Uint32 read;
 BOOL parsed = FALSE;
 int i, res = DMERR_OK;
 memset(&iff, 0, sizeof(iff));
 }
 switch (chunk.id)
 {
 case IFF_ID_BMHD:
+// Check for multiple occurences of BMHD
 if (!dmCheckIFFChunk(&iff.chBMHD, &chunk, FALSE, sizeof(iff.bmhd)))
 return DMERR_FREAD;
+// Read BMHD data
 if (!dm_fread_be16(fp, &iff.bmhd.w) ||
 !dm_fread_be16(fp, &iff.bmhd.h) ||
 !dm_fread_be16(fp, (Uint16 *) &iff.bmhd.x) ||
 !dm_fread_be16(fp, (Uint16 *) &iff.bmhd.y) ||
 !dm_fread_byte(fp, &iff.bmhd.nplanes) ||
 {
 dmError("ILBM: Error reading BMHD chunk.\n");
 return DMERR_FREAD;
 }
 dmMsg(2, "ILBM: BMHD %d x %d @ %d, %d : nplanes=%d, comp=%d, mask=%d\n",
-iff.bmhd.w, iff.bmhd.h, iff.bmhd.x, iff.bmhd.y, iff.bmhd.nplanes, iff.bmhd.compression, iff.bmhd.masking);
+iff.bmhd.w, iff.bmhd.h, iff.bmhd.x, iff.bmhd.y,
+iff.bmhd.nplanes, iff.bmhd.compression, iff.bmhd.masking);
+// Sanity check
+if (iff.bmhd.nplanes < 1 || iff.bmhd.nplanes > 8 ||
+(iff.bmhd.compression != IFF_COMP_NONE &&
+iff.bmhd.compression != IFF_COMP_BYTERUN1) ||
+(iff.bmhd.masking != IFF_MASK_NONE &&
+iff.bmhd.masking != IFF_MASK_HAS_MASK))
+{
+dmError("ILBM: Unsupported features, refusing to load.\n");
+return DMERR_INVALID_DATA;
+}
 if (!dmSkipIFFChunkRest(fp, &chunk, sizeof(iff.bmhd)))
 return DMERR_FREAD;
 break;
 if (iff.chBMHD.count && iff.chBODY.count)
 parsed = TRUE;
 break;
 case IFF_ID_BODY:
+// Check for multiple occurences of CMAP
 if (!dmCheckIFFChunk(&iff.chBODY, &chunk, FALSE, 1))
 return DMERR_FREAD;
+// Check for sanity
 if (!iff.chBMHD.count)
 {
 dmError("ILBM: BODY chunk before BMHD?\n");
 return DMERR_INVALID_DATA;
 }
 dmMsg(2, "ILBM: BODY chunk size %d bytes\n", chunk.size);
-if (fseeko(fp, chunk.size, SEEK_CUR) != 0)
+// Decode the body
-{
+if ((res = dmDecodeILBMBody(fp, &iff, pimg, &read)) != DMERR_OK)
-dmError("ILBM: Error skipping in file.");
+return res;
+if (!dmSkipIFFChunkRest(fp, &chunk, read))
 return DMERR_FREAD;
-}
 if (iff.chCMAP.count)
 parsed = TRUE;
 break;
 default:
 if (chunk.size & 1)
 fgetc(fp);
 }
+// Set colormap after finishing
+if (iff.pal != NULL && iff.ncolors > 0 && *pimg != NULL)
+{
+(*pimg)->ncolors = iff.ncolors;
+(*pimg)->pal = iff.pal;
+}
 return res;
 }
 int dmReadILBMImage(const char *filename, DMImage **pimg)

Mercurial > hg > dmlib

comparison libgfx.c @ 447:0e27860ddcfe