Initial revision

1 files changed, 216 insertions, 0 deletions

diff --git a/rd/read-bmp.c b/rd/read-bmp.c
new file mode 100644
index 0000000..30b5574
--- /dev/null
+++ b/rd/read-bmp.c
@@ -0,0 +1,216 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#ifdef HAVE_ENDIAN_H
+# include <endian.h>
+#endif
+
+#include "readers.h"
+
+/* ---------------------------------------------------------------------- */
+
+typedef unsigned int   uint32;
+typedef unsigned short uint16;
+
+/* bitmap files are little endian */
+#if BYTE_ORDER == LITTLE_ENDIAN
+# define le16_to_cpu(x) (x)
+# define le32_to_cpu(x) (x)
+#elif BYTE_ORDER == BIG_ENDIAN
+# define le16_to_cpu(x) (((x>>8) & 0x00ff) |\
+                         ((x<<8) & 0xff00))
+# define le32_to_cpu(x) (((x>>24) & 0x000000ff) |\
+                         ((x>>8)  & 0x0000ff00) |\
+                         ((x<<8)  & 0x00ff0000) |\
+                         ((x<<24) & 0xff000000))
+#else
+# error "Oops: unknown byte order"
+#endif
+
+/* ---------------------------------------------------------------------- */
+/* load                                                                   */
+
+struct bmp_hdr {
+    uint32 foobar;
+
+    uint32 size;              /* == BitMapInfoHeader */
+    uint32 width;
+    uint32 height;
+    uint16 planes;
+    uint16 bit_cnt;
+    char   compression[4];
+    uint32 image_size;
+    uint32 xpels_meter;
+    uint32 ypels_meter;
+    uint32 num_colors;        /* used colors */
+    uint32 imp_colors;        /* important colors */
+    /* may be more for some codecs */
+};
+
+struct bmp_cmap {
+    unsigned char blue;
+    unsigned char green;
+    unsigned char red;
+    unsigned char unused;
+};
+
+struct bmp_state {
+    struct bmp_hdr  hdr;
+    struct bmp_cmap cmap[256];
+    FILE *fp;
+};
+
+static void*
+bmp_init(FILE *fp, char *filename, unsigned int page,
+	 struct ida_image_info *i, int thumbnail)
+{
+    struct bmp_state *h;
+    
+    h = malloc(sizeof(*h));
+    memset(h,0,sizeof(*h));
+    h->fp = fp;
+
+    fseek(fp,10,SEEK_SET);
+    fread(&h->hdr,sizeof(struct bmp_hdr),1,fp);
+
+#if BYTE_ORDER == BIG_ENDIAN
+    h->hdr.foobar      = le32_to_cpu(h->hdr.foobar);
+    h->hdr.size        = le32_to_cpu(h->hdr.size);
+    h->hdr.width       = le32_to_cpu(h->hdr.width);
+    h->hdr.height      = le32_to_cpu(h->hdr.height);
+    
+    h->hdr.planes      = le16_to_cpu(h->hdr.planes);
+    h->hdr.bit_cnt     = le16_to_cpu(h->hdr.bit_cnt);
+    
+    h->hdr.image_size  = le32_to_cpu(h->hdr.image_size);
+    h->hdr.xpels_meter = le32_to_cpu(h->hdr.xpels_meter);
+    h->hdr.ypels_meter = le32_to_cpu(h->hdr.ypels_meter);
+    h->hdr.num_colors  = le32_to_cpu(h->hdr.num_colors);
+    h->hdr.imp_colors  = le32_to_cpu(h->hdr.imp_colors);
+#endif
+
+    if (debug)
+	fprintf(stderr,"bmp: hdr=%d size=%dx%d planes=%d"
+		" bits=%d size=%d res=%dx%d colors=%d/%d | %d\n",
+		h->hdr.size,h->hdr.width,h->hdr.height,
+		h->hdr.planes,h->hdr.bit_cnt,h->hdr.image_size,
+		h->hdr.xpels_meter,h->hdr.ypels_meter,
+		h->hdr.num_colors,h->hdr.imp_colors,h->hdr.foobar);
+    if (h->hdr.bit_cnt != 1  &&
+	h->hdr.bit_cnt != 4  &&
+	h->hdr.bit_cnt != 8  &&
+	h->hdr.bit_cnt != 24) {
+	fprintf(stderr,"bmp: can't handle depth [%d]\n",h->hdr.bit_cnt);
+	goto oops;
+    }
+    if (h->hdr.compression[0] || h->hdr.compression[1] ||
+	h->hdr.compression[2] || h->hdr.compression[3]) {
+	fprintf(stderr,"bmp: can't handle compressed bitmaps [%c%c%c%c]\n",
+		h->hdr.compression[0],
+		h->hdr.compression[1],
+		h->hdr.compression[2],
+		h->hdr.compression[3]);
+	goto oops;
+    }
+
+    if (0 == h->hdr.num_colors && h->hdr.bit_cnt <= 8)
+	h->hdr.num_colors = (1 << h->hdr.bit_cnt);
+    if (h->hdr.num_colors > 256)
+	h->hdr.num_colors = 256;
+    if (h->hdr.num_colors) {
+	fseek(fp,14+h->hdr.size,SEEK_SET);
+	fread(&h->cmap,sizeof(struct bmp_cmap),h->hdr.num_colors,fp);
+    }
+    
+    i->width  = h->hdr.width;
+    i->height = h->hdr.height;
+    if (h->hdr.xpels_meter)
+	i->dpi = res_m_to_inch(h->hdr.xpels_meter);
+    i->npages = 1;
+    return h;
+
+ oops:
+    free(h);
+    return NULL;
+}
+
+static void
+bmp_read(unsigned char *dst, unsigned int line, void *data)
+{
+    struct bmp_state *h = data;
+    unsigned int ll,y,x,pixel,byte = 0;
+    
+    ll = (((h->hdr.width * h->hdr.bit_cnt + 31) & ~0x1f) >> 3);
+    y  = h->hdr.height - line - 1;
+    fseek(h->fp,h->hdr.foobar + y * ll,SEEK_SET);
+
+    switch (h->hdr.bit_cnt) {
+    case 1:
+	for (x = 0; x < h->hdr.width; x++) {
+	    if (0 == (x & 0x07))
+		byte = fgetc(h->fp);
+	    pixel = byte & (0x80 >> (x & 0x07)) ? 1 : 0;
+	    *(dst++) = h->cmap[pixel].red;
+	    *(dst++) = h->cmap[pixel].green;
+	    *(dst++) = h->cmap[pixel].blue;
+	}
+	break;
+    case 4:
+	for (x = 0; x < h->hdr.width; x++) {
+	    if (x & 1) {
+		pixel = byte & 0xf;
+	    } else {
+		byte = fgetc(h->fp);
+		pixel = byte >> 4;
+	    }
+	    *(dst++) = h->cmap[pixel].red;
+	    *(dst++) = h->cmap[pixel].green;
+	    *(dst++) = h->cmap[pixel].blue;
+	}
+	break;
+    case 8:
+	for (x = 0; x < h->hdr.width; x++) {
+	    pixel = fgetc(h->fp);
+	    *(dst++) = h->cmap[pixel].red;
+	    *(dst++) = h->cmap[pixel].green;
+	    *(dst++) = h->cmap[pixel].blue;
+	}
+	break;
+    case 24:
+	for (x = 0; x < h->hdr.width; x++) {
+	    dst[2] = fgetc(h->fp);
+	    dst[1] = fgetc(h->fp);
+	    dst[0] = fgetc(h->fp);
+	    dst += 3;
+	}
+	break;
+    default:
+	memset(dst,128,h->hdr.width*3);
+	break;
+    }
+}
+
+static void
+bmp_done(void *data)
+{
+    struct bmp_state *h = data;
+
+    fclose(h->fp);
+    free(h);
+}
+
+static struct ida_loader bmp_loader = {
+    magic: "BM",
+    moff:  0,
+    mlen:  2,
+    name:  "bmp",
+    init:  bmp_init,
+    read:  bmp_read,
+    done:  bmp_done,
+};
+
+static void __init init_rd(void)
+{
+    load_register(&bmp_loader);
+}