]> git.draconx.ca Git - liblbx.git/blobdiff - src/image.c
liblbx: Add a hard check for image leadin versus frame count.
[liblbx.git] / src / image.c
index f407a2d72d594157f4d05b353364c5720baa8f9d..adc6a43427289a20b581255abd70be6c1b3c908f 100644 (file)
@@ -1,7 +1,7 @@
 /*
  * 2ooM: The Master of Orion II Reverse Engineering Project
  * Library for working with LBX image files.
- * Copyright © 2006-2011 Nick Bowler
+ * Copyright © 2006-2011, 2013-2014 Nick Bowler
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +20,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
+#include <stdbool.h>
+#include <inttypes.h>
 #include <errno.h>
 
 #include "pack.h"
 
 #define HDR_LEN 12
 
+/* States for image readout */
+enum {
+       READ_STATE_INIT,
+       READ_STATE_HEADER,
+       READ_STATE_DATA,
+       READ_STATE_DONE,
+};
+
 struct lbx_image_priv {
        struct lbx_image pub;
 
        unsigned short wtf, flags;
-       unsigned char  wtf2, leadin;
-       unsigned short palstart, palcount;
+       unsigned char  wtf2;
 
        const struct lbx_file_ops *fops;
        int (*dtor)(void *handle);
        void *f;
 
-       long paloff;
-
-       int currentframe;
-       int currentx, currenty;
-       unsigned char **framedata;
-       unsigned char **mask;
+       /* State of frame readout */
+       unsigned currentx, currenty, currentn;
+       int read_state;
 
        unsigned long offsets[];
 };
@@ -76,13 +82,23 @@ static struct lbx_image_priv *lbx_img_init(unsigned char hdr[static HDR_LEN])
                .wtf        = unpack_16_le(hdr+4),
                .pub.frames = hdr[6],
                .wtf2       = hdr[7],
-               .leadin     = hdr[8],
+               .pub.leadin = hdr[8],
                .pub.chunk  = hdr[9],
                .flags      = unpack_16_le(hdr+10),
-
-               .currentframe = -1,
        };
 
+       if (img->flags & FLAG_OVERWRITE)
+               img->pub.chunk = 1;
+
+       if (img->flags & FLAG_LOOPING)
+               img->pub.leadin = 0;
+
+       if (img->pub.leadin >= img->pub.frames) {
+               lbx_error_raise(LBX_EFORMAT);
+               free(img);
+               return NULL;
+       }
+
        return img;
 }
 
@@ -114,7 +130,6 @@ struct lbx_image *lbx_img_open(void *f, const struct lbx_file_ops *fops,
         */
        _lbx_assert(img->wtf  == 0); /* version? */
        _lbx_assert(img->wtf2 == 0); /* very likely is simply reserved. */
-       _lbx_assert(img->pub.frames > img->leadin);
        _lbx_assert(!(img->flags & ~FLAG_ALL));
 
        /* Read all offsets.  Should be merged with identical code in lbx.c */
@@ -131,27 +146,6 @@ struct lbx_image *lbx_img_open(void *f, const struct lbx_file_ops *fops,
                img->offsets[i] = unpack_32_le(buf);
        }
 
-       if (img->flags & FLAG_PALETTE) {
-               unsigned char buf[4];
-
-               if (fops->read(buf, sizeof buf, f) != sizeof buf) {
-                       if (fops->eof(f))
-                               lbx_error_raise(LBX_EEOF);
-                       free(img);
-                       return NULL;
-               }
-
-               img->palstart = unpack_16_le(buf+0);
-               img->palcount = unpack_16_le(buf+2);
-               img->paloff   = fops->tell(f);
-
-               if (img->palstart + img->palcount > 256) {
-                       lbx_error_raise(LBX_EFORMAT);
-                       free(img);
-                       return NULL;
-               }
-       }
-
        return &img->pub;
 }
 
@@ -176,14 +170,17 @@ struct lbx_image *lbx_img_fopen(const char *file)
        FILE *f;
 
        f = fopen(file, "rb");
-       if (!f)
+       if (!f) {
+               lbx_error_raise(-errno);
                return NULL;
+       }
 
        if (fseek(f, 0, SEEK_CUR) == 0)
                return lbx_img_open(f, &lbx_default_fops, file_close);
 
        p = malloc(sizeof *p);
        if (!p) {
+               lbx_error_raise(LBX_ENOMEM);
                fclose(f);
                return NULL;
        }
@@ -192,227 +189,167 @@ struct lbx_image *lbx_img_fopen(const char *file)
        return lbx_img_open(p, &lbx_pipe_fops, pipe_close);
 }
 
-static int _lbx_drawrow(int first, struct lbx_image_priv *img)
+int lbx_img_seek(struct lbx_image *pub, unsigned frame)
 {
-       unsigned short type, count, yval, xval;
-       unsigned char buf[4];
-       unsigned char *pos;
-       size_t rc;
-
-       assert(img->framedata);
-       assert(img->mask);
-
-       if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
-               goto readerr;
-       type = unpack_16_le(buf+0);
+       struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
 
-       if (first) {
-               img->currentx = 0;
-               img->currenty = 0;
-               type = 0;
+       if (frame >= pub->frames) {
+               lbx_error_raise(LBX_EINVAL);
+               return -1;
        }
 
-       if (type == 0) {
-               yval = unpack_16_le(buf+2);
-               if (yval == 1000)
-                       return 1;
+       if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
+               return -1;
+       }
 
-               if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
-                       goto readerr;
-               count = unpack_16_le(buf+0);
+       if (!(img->flags & FLAG_RAW)) {
+               unsigned char buf[4];
 
-               xval = unpack_16_le(buf+2);
-               if (xval == 1000)
-                       return 1;
+               /* Read frame header */
+               if (img->fops->read(buf, 4, img->f) != 4) {
+                       if (img->fops->eof(img->f))
+                               lbx_error_raise(LBX_EEOF);
+                       return -1;
+               }
 
-               /* Ensure that the row fits in the image. */
-               if (img->pub.height - img->currenty <= yval
-                   || xval >= img->pub.width) {
+               if (unpack_16_le(buf) != 1) {
                        lbx_error_raise(LBX_EFORMAT);
                        return -1;
                }
 
-               img->currenty += yval;
-               img->currentx  = xval;
-       } else {
-               xval = unpack_16_le(buf+2);
-
-               if (img->pub.width - img->currentx <= xval) {
+               img->currentx = 0;
+               img->currenty = unpack_16_le(buf+2);
+               if (img->currenty > img->pub.height) {
                        lbx_error_raise(LBX_EFORMAT);
                        return -1;
                }
-               img->currentx += xval;
-
-               count = type;
-       }
-
-       if (count > img->pub.width - img->currentx) {
-               lbx_error_raise(LBX_EFORMAT);
-               return -1;
-       }
-
-       memset(&img->mask[img->currenty][img->currentx], 1, count);
-
-       pos = &img->framedata[img->currenty][img->currentx];
-       rc  = img->fops->read(pos, count, img->f);
-       img->currentx += rc;
-
-       if (rc < count)
-               goto readerr;
-
-       if (count % 2) {
-               if (img->fops->read(buf, 1, img->f) != 1)
-                       goto readerr;
        }
 
+       img->read_state = READ_STATE_HEADER;
        return 0;
-readerr:
-       if (img->fops->eof(img->f))
-               lbx_error_raise(LBX_EEOF);
-       return -1;
 }
 
-static unsigned char **allocframebuffer(size_t width, size_t height)
+long lbx_img_read_row_header(struct lbx_image *pub, unsigned *x, unsigned *y)
 {
-       unsigned char **new, *tmp;
-       size_t i;
-
-       tmp = calloc(height, width);
-       if (!tmp) {
-               lbx_error_raise(LBX_ENOMEM);
-               return NULL;
-       }
+       struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+       unsigned short length, offset;
+       unsigned char buf[4];
 
-       new = malloc(height * sizeof *new);
-       if (!new) {
-               lbx_error_raise(LBX_ENOMEM);
-               free(tmp);
-               return NULL;
+       if (img->read_state != READ_STATE_HEADER) {
+               lbx_error_raise(LBX_EINVAL);
+               return -1;
        }
 
-       for (i = 0; i < height; i++) {
-               new[i] = tmp + i * width;
+       /* Raw images have no row headers */
+       if (img->flags & FLAG_RAW) {
+               img->currentn = img->pub.width;
+               *y = img->currenty++;
+               *x = 0;
+
+               if (*y < img->pub.height) {
+                       img->read_state = READ_STATE_DATA;
+                       return img->currentn;
+               } else {
+                       img->read_state = READ_STATE_DONE;
+                       return 0;
+               }
        }
 
-       return new;
-}
+       do {
+               if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf) {
+                       if (img->fops->eof(img->f))
+                               lbx_error_raise(LBX_EEOF);
+                       return -1;
+               }
 
-static unsigned char **read_raw_frame(struct lbx_image_priv *img, int frame)
-{
-       unsigned long size = img->pub.width * img->pub.height;
+               length = unpack_16_le(buf+0);
+               offset = unpack_16_le(buf+2);
 
-       assert(img->flags & FLAG_RAW);
+               if (length == 0) {
+                       if (offset == 1000) {
+                               img->read_state = READ_STATE_DONE;
+                               return 0;
+                       } else if (offset > img->pub.height - img->currenty) {
+                               lbx_error_raise(LBX_EFORMAT);
+                               return -1;
+                       }
 
-       if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
-               return NULL;
-       }
+                       img->currenty += offset;
+                       img->currentx  = 0;
+               }
+       } while (length == 0);
 
-       if (img->fops->read(img->framedata[0], size, img->f) != size) {
-               if (img->fops->eof(img->f))
-                       lbx_error_raise(LBX_EEOF);
-               return NULL;
+       if (offset > img->pub.width - img->currentx) {
+               lbx_error_raise(LBX_EFORMAT);
+               return -1;
        }
-       memset(img->mask[0], 1, size);
+       img->currentx += offset;
 
-       if (img->fops->tell(img->f) > img->offsets[frame+1]) {
+       if (length > img->pub.width - img->currentx) {
                lbx_error_raise(LBX_EFORMAT);
-               return NULL;
+               return -1;
        }
+       img->currentn = length;
 
-       return img->framedata;
+       img->read_state = READ_STATE_DATA;
+       *x = img->currentx;
+       *y = img->currenty;
+
+       return img->currentn;
 }
 
-unsigned char **lbx_img_getframe(struct lbx_image *pub, int frame)
+long lbx_img_read_row_data(struct lbx_image *pub, void *buf)
 {
        struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
 
-       if (frame >= pub->frames || frame < 0) {
-               lbx_error_raise(LBX_ENOENT);
-               return NULL;
-       }
-
-       if (!img->framedata) {
-               img->framedata = allocframebuffer(pub->width, pub->height);
-               if (!img->framedata)
-                       return NULL;
+       if (img->read_state != READ_STATE_DATA) {
+               lbx_error_raise(LBX_EINVAL);
+               return -1;
        }
 
-       if (!img->mask) {
-               img->mask = allocframebuffer(pub->width, pub->height);
-               if (!img->mask)
-                       return NULL;
+       if (img->fops->read(buf, img->currentn, img->f) != img->currentn) {
+               if (img->fops->eof(img->f))
+                       lbx_error_raise(LBX_EEOF);
+               return -1;
        }
 
-       if (img->flags & FLAG_RAW)
-               return read_raw_frame(img, frame);
-
-       if ((img->flags & FLAG_OVERWRITE)
-            || (pub->chunk && !(frame % pub->chunk))) {
-               /* Clear the slate. */
-               img->currentframe = -1;
-               memset(img->framedata[0], 0, pub->width * pub->height);
-               memset(img->mask[0],      0, pub->width * pub->height);
-       } else {
-               /* Start over if we are backtracking. */
-               if (img->currentframe > frame) {
-                       memset(img->mask[0], 0, pub->width * pub->height);
-                       img->currentframe = -1;
-               }
-
-               /* We must have previous frame decoded to continue. */
-               if (frame > img->currentframe + 1) {
-                       if (!lbx_img_getframe(pub, frame-1))
-                               return NULL;
+       if (!(img->flags & FLAG_RAW)) {
+               /* Skip padding byte, if any */
+               if (img->currentn % 2) {
+                       if (img->fops->seek(img->f, 1, SEEK_CUR))
+                               return -1;
                }
        }
 
-       if (img->currentframe != frame) {
-               int rc, first = 1;
-
-               if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
-                       return NULL;
-               }
-
-               do {
-                       rc = _lbx_drawrow(first, img);
-                       if (rc == -1)
-                               return NULL;
-                       first = 0;
+       img->read_state = READ_STATE_HEADER;
+       img->currentx += img->currentn;
 
-                       if (img->fops->tell(img->f) > img->offsets[frame+1]) {
-                               lbx_error_raise(LBX_EFORMAT);
-                               return NULL;
-                       }
-               } while (!rc);
-       }
-
-       img->currentframe = frame;
-       return img->framedata;
+       return img->currentn;
 }
 
-int
-lbx_img_loadpalette(void *f, const struct lbx_file_ops *fops,
-                    struct lbx_colour palette[static 256])
+static int read_palette(void *f, const struct lbx_file_ops *fops,
+                        struct lbx_colour *palette, unsigned count,
+                       bool external)
 {
-       unsigned char entry[4];
-       int i;
+       assert(count <= 256);
+       for (unsigned i = 0; i < count; i++) {
+               unsigned char buf[4];
 
-       for (i = 0; i < 256; i++) {
-               if (fops->read(entry, sizeof entry, f) != sizeof entry) {
+               if (fops->read(buf, 4, f) != 4) {
                        if (fops->eof(f))
                                lbx_error_raise(LBX_EEOF);
                        return -1;
                }
 
-               if (entry[0] != 1) {
+               if (buf[0] != external) {
                        lbx_error_raise(LBX_EFORMAT);
                        return -1;
                }
 
                palette[i] = (struct lbx_colour) {
-                       .red    = entry[1] << 2,
-                       .green  = entry[2] << 2,
-                       .blue   = entry[3] << 2,
+                       .red    = buf[1] & 0x3f,
+                       .green  = buf[2] & 0x3f,
+                       .blue   = buf[3] & 0x3f,
                        .active = 1,
                };
        }
@@ -420,95 +357,63 @@ lbx_img_loadpalette(void *f, const struct lbx_file_ops *fops,
        return 0;
 }
 
-int
-lbx_img_getpalette(struct lbx_image *pub, struct lbx_colour palette[static 256])
+int lbx_img_loadpalette(void *f, const struct lbx_file_ops *fops,
+                        struct lbx_colour *palette)
+{
+       return read_palette(f, fops, palette, 256, true);
+}
+
+int lbx_img_getpalette(struct lbx_image *pub, struct lbx_colour *out)
 {
        struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
-       unsigned char entry[4];
-       unsigned int i;
-       size_t rc;
+       unsigned long palette_start, palette_count, palette_offset;
+       unsigned char buf[4];
+       int rc;
 
        /* Do nothing if the image doesn't have embedded palette data. */
        if (!(img->flags & FLAG_PALETTE))
                return 0;
 
-       if (img->fops->seek(img->f, img->paloff, SEEK_SET)) {
+       palette_offset = 16 + 4ul * img->pub.frames;
+       if (img->fops->seek(img->f, palette_offset, SEEK_SET)) {
                return -1;
        }
 
-       for (i = 0; i < img->palcount; i++) {
-               rc = img->fops->read(entry, sizeof entry, img->f);
-               if (rc < sizeof entry) {
-                       goto readerr;
-               }
+       /* Read embedded palette header */
+       if (img->fops->read(buf, 4, img->f) < 4)
+               goto readerr;
 
-               if (entry[0] != 0) {
-                       lbx_error_raise(LBX_EFORMAT);
-                       return -1;
-               }
+       palette_start = unpack_16_le(buf+0);
+       palette_count = unpack_16_le(buf+2);
+       if (palette_start + palette_count > 256) {
+               lbx_error_raise(LBX_EFORMAT);
+               return -1;
+       }
 
-               palette[img->palstart + i] = (struct lbx_colour){
-                       .red    = entry[1] << 2,
-                       .green  = entry[2] << 2,
-                       .blue   = entry[3] << 2,
-                       .active = 1,
-               };
+       if (out) {
+               rc = read_palette(img->f, img->fops,
+                                 out+palette_start, palette_count,
+                                 false);
+               if (rc < 0)
+                       return -1;
        }
 
-       return 0;
+       return palette_count;
 readerr:
        if (img->fops->eof(img->f))
                lbx_error_raise(LBX_EEOF);
        return -1;
 }
 
-void lbx_img_getinfo(struct lbx_image *pub, struct lbx_imginfo *info)
-{
-       struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
-
-       *info = (struct lbx_imginfo) {
-               .palettesz  = (img->flags & FLAG_PALETTE) ? img->palcount : 0,
-       };
-
-       /* There seems to be two ways of specifying that an image loops. */
-       if (img->flags & FLAG_LOOPING) {
-               info->loopstart = 0;
-               info->looping   = 1;
-       } else if (img->leadin != pub->frames - 1) {
-               info->loopstart = img->leadin;
-               info->looping   = 1;
-       }
-}
-
-unsigned char **lbx_img_getmask(struct lbx_image *pub)
-{
-       struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
-
-       return img->mask;
-}
-
 int lbx_img_close(struct lbx_image *pub)
 {
        struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
        int rc = 0;
 
-       if (img) {
-               if (img->framedata) {
-                       free(img->framedata[0]);
-                       free(img->framedata);
-               }
-
-               if (img->mask) {
-                       free(img->mask[0]);
-                       free(img->mask);
-               }
-
-               if (img && img->dtor) {
-                       rc = img->dtor(img->f);
-               }
-
-               free(img);
+       if (img && img->dtor) {
+               rc = img->dtor(img->f);
        }
+       free(img);
 
        return rc;
 }