dmlib: src/libgfx.c comparison

comparison src/libgfx.c @ 1279:0d3f5f44c0c4

Somewhat improve PCX read support in libgfx.

author	Matti Hamalainen <ccr@tnsp.org>
date	Fri, 18 Aug 2017 02:03:15 +0300
parents	4e074b9b4789
children	300a51e98fc3

comparison

equal deleted inserted replaced

-:5206e3d4e6b7
+:0d3f5f44c0c4
 return res;
 }
 #endif
+#define DMPCX_PAL_COLORS  16 // Number of internal palette colors
 typedef struct
 {
 Uint8 r,g,b;
 } DMPCXColor;
 typedef struct
 {
-Uint8 manufacturer,
+Uint8 manufacturer,     // always 0x0a
-version,
+version,        // Z-Soft PCX Paintbrush version:
-encoding,
+// 0 = v2.5, 2 = v2.8 with palette, 3 = v2.8 without palette, 5 = v3.0 or better
-bpp;
+encoding,       // usually 0x01 = RLE, 0x00 = uncompressed
+bitsPerPlane;   // bits per pixel per plane
 Uint16 xmin, ymin, xmax, ymax;
-Uint16 hres, vres;
+Uint16 hres, vres;      // resolution in DPI, can be image dimensions as well.
-DMPCXColor colormap[16];
+DMPCXColor colorMap[DMPCX_PAL_COLORS];
-Uint8 reserved;
+Uint8 reserved;         // should be set to 0
-Uint8 nplanes;
+Uint8 nplanes;          // number of planes
-Uint16 bpl;
+Uint16 bpl;             // bytes per plane LINE
-Uint16 palinfo;
+Uint16 palInfo;         // 1 = color/BW, 2 = grayscale
-Uint8 filler[58];
+Uint16 hScreenSize, vScreenSize;
+Uint8 filler[54];
 } DMPCXHeader;
 typedef struct
 {
 }
 static int dmWritePCXRow(void *cbdata, Uint8 *row, size_t len)
 {
 DMPCXData *pcx = (DMPCXData *) cbdata;
-int plane;
 size_t soffs = 0;
 //    fprintf(stderr, "%d, %d * %d = %d\n", len, pcx->header->bpl, pcx->header->nplanes, pcx->header->nplanes * pcx->header->bpl);
 pcx->bufOffs = 0;
-for (plane = 0; plane < pcx->header->nplanes; plane++)
+for (int plane = 0; plane < pcx->header->nplanes; plane++)
 {
 Uint8 data = dmPCXGetByte(row, len, soffs++),
 count = 1;
 //        size_t blen = pcx->header->bpl * pcx->header->nplanes;
 // Create PCX header
 dmMemset(&hdr, 0, sizeof(hdr));
 if (spec->paletted)
 {
-int i;
+for (int i = 0; i < (img->ncolors > DMPCX_PAL_COLORS ? DMPCX_PAL_COLORS : img->ncolors); i++)
-for (i = 0; i < (img->ncolors > 16 ? 16 : img->ncolors); i++)
+{
-{
+hdr.colorMap[i].r = img->pal[i].r;
-hdr.colormap[i].r = img->pal[i].r;
+hdr.colorMap[i].g = img->pal[i].g;
-hdr.colormap[i].g = img->pal[i].g;
+hdr.colorMap[i].b = img->pal[i].b;
-hdr.colormap[i].b = img->pal[i].b;
 }
 }
 hdr.manufacturer = 10;
 hdr.version      = 5;
 hdr.encoding     = 1;
-hdr.bpp          = 8;
+hdr.bitsPerPlane = 8;
 hdr.hres         = img->width * spec->scaleX;
 hdr.vres         = img->height * spec->scaleY;
 hdr.xmin         = hdr.ymin = 0;
 hdr.xmax         = hdr.hres - 1;
 hdr.ymax         = hdr.vres - 1;
 hdr.nplanes      = dmImageGetBytesPerPixel(pcx.format);
-hdr.palinfo      = 1;
+hdr.palInfo      = 1;
 res = (img->width * spec->scaleX);
 hdr.bpl = res / 2;
 if (res % 2) hdr.bpl++;
 hdr.bpl *= 2;
 dmMsg(3, "PCX: paletted=%d, nplanes=%d, bpp=%d, bpl=%d\n",
-spec->paletted, hdr.nplanes, hdr.bpp, hdr.bpl);
+spec->paletted, hdr.nplanes, hdr.bitsPerPlane, hdr.bpl);
 pcx.bufLen       = hdr.bpl * 4;
 if ((pcx.buf = dmMalloc(pcx.bufLen)) == NULL)
 {
 res = dmError(DMERR_MALLOC,
 // Write PCX header
 if (!dm_fwrite_byte(pcx.fp, hdr.manufacturer) ||
 !dm_fwrite_byte(pcx.fp, hdr.version) ||
 !dm_fwrite_byte(pcx.fp, hdr.encoding) ||
-!dm_fwrite_byte(pcx.fp, hdr.bpp))
+!dm_fwrite_byte(pcx.fp, hdr.bitsPerPlane))
 {
 res = dmError(DMERR_FWRITE,
 "PCX: Could not write basic header data.\n");
 goto error;
 }
 res = dmError(DMERR_FWRITE,
 "PCX: Could not write image dimensions.\n");
 goto error;
 }
-if (!dm_fwrite_str(pcx.fp, (Uint8 *) &hdr.colormap, sizeof(hdr.colormap)))
+if (!dm_fwrite_str(pcx.fp, (Uint8 *) &hdr.colorMap, sizeof(hdr.colorMap)))
 {
 res = dmError(DMERR_FWRITE,
 "PCX: Could not write colormap.\n");
 goto error;
 }
 if (!dm_fwrite_byte(pcx.fp, hdr.reserved) ||
 !dm_fwrite_byte(pcx.fp, hdr.nplanes) ||
 !dm_fwrite_le16(pcx.fp, hdr.bpl) ||
-!dm_fwrite_le16(pcx.fp, hdr.palinfo) ||
+!dm_fwrite_le16(pcx.fp, hdr.palInfo) ||
 !dm_fwrite_str(pcx.fp, (Uint8 *) &hdr.filler, sizeof(hdr.filler)))
 {
 res = dmError(DMERR_FWRITE,
 "PCX: Could not write header remainder.\n");
 goto error;
 int dmReadPCXImageFILE(FILE *fp, DMImage **pimg)
 {
 DMImage *img;
 DMPCXData pcx;
 DMPCXHeader hdr;
-BOOL paletted;
+int res = 0;
-int res = 0, yc, xc;
-Uint8 *dp;
 pcx.buf = NULL;
 // Read PCX header
 if (!dm_fread_byte(fp, &hdr.manufacturer) ||
 !dm_fread_byte(fp, &hdr.version) ||
 !dm_fread_byte(fp, &hdr.encoding) ||
-!dm_fread_byte(fp, &hdr.bpp))
+!dm_fread_byte(fp, &hdr.bitsPerPlane))
 {
 res = dmError(DMERR_FREAD,
 "PCX: Could not read basic header data.\n");
 goto error;
 }
 if (hdr.manufacturer != 10 ||
 hdr.version != 5 ||
-hdr.encoding != 1 ||
+hdr.encoding != 1)
-hdr.bpp != 8)
 {
 res = dmError(DMERR_NOT_SUPPORTED,
 "PCX: Not a PCX file, or unsupported variant.\n");
 goto error;
 }
 res = dmError(DMERR_FREAD,
 "PCX: Could not read image dimensions.\n");
 goto error;
 }
-if (!dm_fread_str(fp, (Uint8 *) &hdr.colormap, sizeof(hdr.colormap)))
+if (!dm_fread_str(fp, (Uint8 *) &hdr.colorMap, sizeof(hdr.colorMap)))
 {
 res = dmError(DMERR_FREAD,
 "PCX: Could not read colormap.\n");
 goto error;
 }
 if (!dm_fread_byte(fp, &hdr.reserved) ||
 !dm_fread_byte(fp, &hdr.nplanes) ||
 !dm_fread_le16(fp, &hdr.bpl) ||
-!dm_fread_le16(fp, &hdr.palinfo) ||
+!dm_fread_le16(fp, &hdr.palInfo) ||
 !dm_fread_str(fp, (Uint8 *) &hdr.filler, sizeof(hdr.filler)))
 {
 res = dmError(DMERR_FREAD,
 "PCX: Could not read header remainder.\n");
 goto error;
 }
-if (hdr.nplanes != 3 && hdr.nplanes != 1)
+if (hdr.nplanes < 1 || hdr.nplanes > 8)
 {
-res = dmError(DMERR_FREAD,
+res = dmError(DMERR_NOT_SUPPORTED,
 "PCX: Unsupported number of bitplanes %d.\n",
 hdr.nplanes);
 goto error;
 }
 res = dmError(DMERR_MALLOC,
 "PCX: Could not allocate image structure.\n");
 goto error;
 }
-paletted = hdr.nplanes == 1;
+if (hdr.bpl < (img->width * hdr.bitsPerPlane) / 8)
+{
+res = dmError(DMERR_MALLOC,
+"PCX: The bytes per plane line value %d is smaller than width*bpp/8 = %d!\n",
+hdr.bpl, (img->width * hdr.bitsPerPlane) / 8);
+goto error;
+}
 pcx.bufLen = hdr.nplanes * hdr.bpl;
 if ((pcx.buf = dmMalloc(pcx.bufLen)) == NULL)
 {
 res = dmError(DMERR_MALLOC,
 "PCX: Could not allocate RLE buffer.\n");
 goto error;
 }
 // Read image data
-dp = img->data;
+Uint8 *dp = img->data;
-for (yc = 0; yc < img->height; yc++)
+for (int yc = 0; yc < img->height; yc++)
 {
 // Decode row of RLE'd data
 if (!dmPCXDecodeRLERow(fp, pcx.buf, pcx.bufLen))
 {
 res = dmError(DMERR_INVALID_DATA,
-"PCX: Error decoding RLE data.\n");
+"PCX: Error decoding RLE compressed data.\n");
 goto error;
 }
 // Decode bitplanes
-switch (hdr.nplanes)
+switch (hdr.bitsPerPlane)
 {
-case 1:
+case 8:
-memcpy(dp, pcx.buf, img->width);
+for (int nplane = 0; nplane < hdr.nplanes; nplane++)
-break;
-case 3:
 {
-Uint8 *dptr = dp,
+Uint8 *dptr = dp + nplane,
-*sptr1 = pcx.buf,
+*sptr = pcx.buf + (hdr.bpl * nplane);
-*sptr2 = sptr1 + hdr.bpl,
-*sptr3 = sptr2 + hdr.bpl;
+for (int xc = 0; xc < img->width; xc += hdr.nplanes, dptr += hdr.nplanes, sptr++)
+*dptr = *sptr;
-for (xc = 0; xc < img->width; xc++)
-{
-*dptr++ = *sptr1++;
-*dptr++ = *sptr2++;
-*dptr++ = *sptr3++;
-}
 }
 break;
+default:
+res = dmError(DMERR_INVALID_DATA,
+"PCX: Unsupported number of bits per plane %d.\n",
+hdr.bitsPerPlane);
+goto error;
 }
 dp += img->pitch;
 }
-// Read VGA palette
+// Read additional VGA palette, if available
-if (paletted)
+{
-{
+int ncolors;
-int i, ncolors;
 Uint8 tmpb;
 BOOL read;
 if (!dm_fread_byte(fp, &tmpb) || tmpb != 0x0C)
 {
 goto error;
 }
 if (read)
 {
+// Okay, attempt to read the palette data
 if (!dmReadPaletteData(fp, img->pal, ncolors))
 {
 res = dmError(DMERR_FREAD,
 "PCX: Error reading palette.\n");
 goto error;
 }
 }
 else
 {
-for (i = 0; i < img->ncolors; i++)
+// If the extra palette is not available, copy the colors from
-{
+// the header palette to our internal palette structure.
-if (i < 16)
+for (int i = 0; i < (img->ncolors > DMPCX_PAL_COLORS ? DMPCX_PAL_COLORS : img->ncolors); i++)
 {
-img->pal[i].r = hdr.colormap[i].r;
+img->pal[i].r = hdr.colorMap[i].r;
-img->pal[i].g = hdr.colormap[i].g;
+img->pal[i].g = hdr.colorMap[i].g;
-img->pal[i].b = hdr.colormap[i].b;
+img->pal[i].b = hdr.colorMap[i].b;
-}
 }
 }
 }
 error:

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comparison src/libgfx.c @ 1279:0d3f5f44c0c4