liblbx: Parameterise I/O functions for image handling.

[liblbx.git] / src / image.c

diff --git a/src/image.c b/src/image.c
index 9bc4985942c69411228d85b7e05451c26a135279..f98238e49edb0f79395551d14ed4c7c9e66599fb 100644 (file)
--- a/src/image.c
+++ b/src/image.c
@@ -43,8 +43,11 @@ struct lbx_image {
        unsigned short frames, leadin;
        unsigned short palstart, palcount;
 
-       FILE *f;
-       long foff, paloff;
+       const struct lbx_file_ops *fops;
+       int (*dtor)(void *handle);
+       void *f;
+
+       long paloff;
 
        int currentframe;
        int currentx, currenty;
@@ -79,15 +82,15 @@ static struct lbx_image *lbximg_init(unsigned char hdr[static HDR_LEN])
        return img;
 }
 
-struct lbx_image *lbximg_fopen(FILE *f)
+struct lbx_image *lbximg_open(void *f, const struct lbx_file_ops *fops,
+                              int (*destructor)(void *))
 {
        unsigned char hdr_buf[HDR_LEN];
        struct lbx_image *img;
-       size_t rc;
 
-       if (fread(hdr_buf, 1, sizeof hdr_buf, f) != sizeof hdr_buf) {
+       if (fops->read(hdr_buf, sizeof hdr_buf, f) != sizeof hdr_buf) {
                lbx_errno = -errno;
-               if (feof(f))
+               if (fops->eof(f))
                        lbx_errno = LBX_EEOF;
                return NULL;
        }
@@ -97,7 +100,8 @@ struct lbx_image *lbximg_fopen(FILE *f)
                return NULL;
 
        img->f    = f;
-       img->foff = sizeof hdr_buf;
+       img->fops = fops;
+       img->dtor = destructor;
 
        /*
         * DEBUG ONLY.  These assertions exist to catch otherwise valid image
@@ -113,24 +117,23 @@ struct lbx_image *lbximg_fopen(FILE *f)
        for (unsigned i = 0; i <= img->frames; i++) {
                unsigned char buf[4];
 
-               if (fread(buf, 1, sizeof buf, f) != sizeof buf) {
+               if (fops->read(buf, sizeof buf, f) != sizeof buf) {
                        lbx_errno = -errno;
-                       if (feof(f))
+                       if (fops->eof(f))
                                lbx_errno = LBX_EEOF;
                        free(img);
                        return NULL;
                }
 
                img->offsets[i] = unpack_32_le(buf);
-               img->foff += 4;
        }
 
        if (img->flags & FLAG_PALETTE) {
                unsigned char buf[4];
 
-               if (fread(buf, 1, sizeof buf, f) != sizeof buf) {
+               if (fops->read(buf, sizeof buf, f) != sizeof buf) {
                        lbx_errno = -errno;
-                       if (feof(f))
+                       if (fops->eof(f))
                                lbx_errno = LBX_EEOF;
                        free(img);
                        return NULL;
@@ -138,8 +141,7 @@ struct lbx_image *lbximg_fopen(FILE *f)
 
                img->palstart = unpack_16_le(buf+0);
                img->palcount = unpack_16_le(buf+2);
-               img->foff    += sizeof buf;
-               img->paloff   = img->foff;
+               img->paloff   = fops->tell(f);
 
                if (img->palstart + img->palcount > 256) {
                        lbx_errno = LBX_EFORMAT;
@@ -151,6 +153,11 @@ struct lbx_image *lbximg_fopen(FILE *f)
        return img;
 }
 
+struct lbx_image *lbximg_fopen(FILE *f)
+{
+       return lbximg_open(f, &lbx_default_fops, NULL);
+}
+
 static int _lbx_drawrow(int first, struct lbx_image *img)
 {
        unsigned short type, count, yval, xval;
@@ -161,9 +168,8 @@ static int _lbx_drawrow(int first, struct lbx_image *img)
        assert(img->framedata);
        assert(img->mask);
 
-       if (fread(buf, 1, sizeof buf, img->f) != sizeof buf)
+       if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
                goto readerr;
-       img->foff += 4;
        type = unpack_16_le(buf+0);
 
        if (first) {
@@ -177,9 +183,8 @@ static int _lbx_drawrow(int first, struct lbx_image *img)
                if (yval == 1000)
                        return 1;
 
-               if (fread(buf, 1, sizeof buf, img->f) != sizeof buf)
+               if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
                        goto readerr;
-               img->foff += 4;
                count = unpack_16_le(buf+0);
 
                xval = unpack_16_le(buf+2);
@@ -214,26 +219,22 @@ static int _lbx_drawrow(int first, struct lbx_image *img)
        memset(&img->mask[img->currenty][img->currentx], 1, count);
 
        pos = &img->framedata[img->currenty][img->currentx];
-       rc  = fread(pos, 1, count, img->f);
+       rc  = img->fops->read(pos, count, img->f);
        img->currentx += rc;
-       img->foff     += rc;
 
        if (rc < count)
                goto readerr;
 
        if (count % 2) {
-               if (fread(buf, 1, 1, img->f) != 1)
+               if (img->fops->read(buf, 1, img->f) != 1)
                        goto readerr;
-               img->foff += 1;
        }
 
        return 0;
 readerr:
-       if (feof(img->f)) {
+       lbx_errno = -errno;
+       if (img->fops->eof(img->f))
                lbx_errno = LBX_EEOF;
-       } else {
-               lbx_errno = -errno;
-       }
        return -1;
 }
 
@@ -300,8 +301,10 @@ unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
        if (img->currentframe != frame) {
                int rc, first = 1;
 
-               if (_lbx_fseek(img->f, &img->foff, img->offsets[frame]) == -1)
+               if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
+                       lbx_errno = -errno;
                        return NULL;
+               }
 
                do {
                        rc = _lbx_drawrow(first, img);
@@ -309,7 +312,7 @@ unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
                                return NULL;
                        first = 0;
 
-                       if (!rc && img->foff > img->offsets[frame+1]) {
+                       if (img->fops->tell(img->f) > img->offsets[frame+1]) {
                                lbx_errno = LBX_EFORMAT;
                                return NULL;
                        }
@@ -357,12 +360,13 @@ lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
        if (!(img->flags & FLAG_PALETTE))
                return 0;
 
-       if (_lbx_fseek(img->f, &img->foff, img->paloff) == -1)
+       if (img->fops->seek(img->f, img->paloff, SEEK_SET)) {
+               lbx_errno = -errno;
                return -1;
+       }
 
        for (i = 0; i < img->palcount; i++) {
-               rc = fread(entry, 1, sizeof entry, img->f);
-               img->foff += rc;
+               rc = img->fops->read(entry, sizeof entry, img->f);
 
                if (rc < sizeof entry) {
                        goto readerr;
@@ -382,7 +386,7 @@ lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
 
        return 0;
 readerr:
-       lbx_errno = feof(img->f) ? LBX_EEOF : -errno;
+       lbx_errno = img->fops->eof(img->f) ? LBX_EEOF : -errno;
        return -1;
 }
 
@@ -410,23 +414,27 @@ unsigned char **lbximg_getmask(struct lbx_image *img)
        return img->mask;
 }
 
-void lbximg_close(struct lbx_image *img)
+int lbximg_close(struct lbx_image *img)
 {
-       if (!img) return;
+       int rc = 0;
 
-       if (img->framedata) {
-               free(img->framedata[0]);
-               free(img->framedata);
-       }
+       if (img) {
+               if (img->framedata) {
+                       free(img->framedata[0]);
+                       free(img->framedata);
+               }
 
-       if (img->mask) {
-               free(img->mask[0]);
-               free(img->mask);
-       }
+               if (img->mask) {
+                       free(img->mask[0]);
+                       free(img->mask);
+               }
+
+               if (img && img->dtor) {
+                       rc = img->dtor(img->f);
+               }
 
-       if (img->f) {
-               fclose(img->f);
+               free(img);
        }
 
-       free(img);
+       return rc;
 }