1 files changed, 143 insertions, 0 deletions
diff --git a/thumbnail.c b/thumbnail.c
new file mode 100644
index 0000000..9e425cb
--- /dev/null
+++ b/thumbnail.c
@@ -0,0 +1,143 @@
+#include "thumbnail.h"
+#include <magick/api.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+/* http://www.graphicsmagick.org/api/api.html */
+
+int thumbnail_create(const char *const src, const char *const dst)
+{
+    int ret = -1;
+    const size_t slen = strlen(src), dlen = strlen(dst);
+    ImageInfo *info = NULL;
+    Image *i = NULL, *t = NULL;
+    ExceptionInfo exc;
+
+    InitializeMagick(NULL);
+    GetExceptionInfo(&exc);
+
+    if (slen >= sizeof i->filename)
+    {
+        fprintf(stderr, "%s: src maximum length exceeded (%zu, max %zu)\n",
+            __func__, slen, sizeof i->filename - 1);
+        goto end;
+    }
+    else if (dlen >= sizeof t->filename)
+    {
+        fprintf(stderr, "%s: dst maximum length exceeded (%zu, max %zu)\n",
+            __func__, slen, sizeof t->filename - 1);
+        goto end;
+    }
+    else if (!(info = CloneImageInfo(NULL)))
+    {
+        fprintf(stderr, "%s: CloneImageInfo failed\n", __func__);
+        goto end;
+    }
+
+    strcpy(info->filename, src);
+    info->adjoin = MagickTrue;
+
+    if (!(i = ReadImage(info, &exc)))
+    {
+        if (exc.severity == MissingDelegateError)
+            /* Non-image file format. */
+            ret = 1;
+        else
+            fprintf(stderr, "%s: ReadImage failed: "
+                "reason: %s, description: %s\n",
+                __func__, exc.reason, exc.description);
+
+        goto end;
+    }
+
+    const unsigned long y = i->rows > THUMBNAIL_HEIGHT ?
+        THUMBNAIL_HEIGHT : i->rows,
+        x = y * i->columns / i->rows;
+
+    if (!(t = ResizeImage(i, x, y, PointFilter, 1, &exc)))
+    {
+        fprintf(stderr, "%s: ResizeImage failed, "
+            "reason: %s, description: %s\n",
+            __func__, exc.reason, exc.description);
+        goto end;
+    }
+    else if (WriteImages(info, t, dst, &exc) != MagickPass)
+    {
+        fprintf(stderr, "%s: WriteImages failed, "
+            "reason: %s, description: %s\n",
+            __func__, exc.reason, exc.description);
+        goto end;
+    }
+
+    ret = 0;
+
+end:
+    DestroyImageInfo(info);
+    DestroyImage(i);
+    DestroyImage(t);
+    DestroyExceptionInfo(&exc);
+    DestroyMagick();
+    return ret;
+}
+
+bool thumbnail_configured(void)
+{
+    return true;
+}
+
+int thumbnail_dim(const char *const path, struct thumbnail_dim *const d)
+{
+    int ret = -1;
+    const size_t slen = strlen(path);
+    ImageInfo *info = NULL;
+    Image *i = NULL;
+    ExceptionInfo exc;
+
+    InitializeMagick(NULL);
+    GetExceptionInfo(&exc);
+
+    if (slen >= sizeof i->filename)
+    {
+        fprintf(stderr, "%s: src maximum length exceeded (%zu, max %zu)\n",
+            __func__, slen, sizeof i->filename - 1);
+        goto end;
+    }
+    else if (!(info = CloneImageInfo(NULL)))
+    {
+        fprintf(stderr, "%s: CloneImageInfo failed\n", __func__);
+        goto end;
+    }
+
+    strcpy(info->filename, path);
+    info->adjoin = MagickTrue;
+
+    if (!(i = ReadImage(info, &exc)))
+    {
+        if (exc.severity == MissingDelegateError)
+            /* Non-image file format. */
+            ret = 1;
+        else
+            fprintf(stderr, "%s: ReadImage failed: "
+                "reason: %s, description: %s\n",
+                __func__, exc.reason, exc.description);
+
+        goto end;
+    }
+
+    *d = (const struct thumbnail_dim)
+    {
+        .w = i->columns,
+        .h = i->rows
+    };
+
+    ret = 0;
+
+end:
+    DestroyImageInfo(info);
+    DestroyImage(i);
+    DestroyExceptionInfo(&exc);
+    DestroyMagick();
+    return ret;
+}