Added farbfeld parser

Signed-off-by: alttabber <[email protected]>

README.md

@@ -17,6 +17,7 @@ Fully customizable and lightweight image viewer for Wayland based display server
   - PNM (built-in);
   - TGA (built-in);
   - QOI (built-in).
+  - Farbfeld (built-in).
 - Fully customizable keyboard bindings, colors, and [many other](https://github.com/artemsen/swayimg/blob/master/extra/swayimgrc) parameters;
 - Loading images from files and pipes;
 - Gallery and viewer modes with slideshow and animation support;

meson.build

@@ -207,6 +207,7 @@ sources = [
   'src/formats/pnm.c',
   'src/formats/qoi.c',
   'src/formats/tga.c',
+  'src/formats/ff.c',
   xdg_shell_h,
   xdg_shell_c,
   wp_content_type_v1_h,

src/formats/ff.c

@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: MIT
+// farbfeld format decoder
+
+#include "../loader.h"
+
+#include <arpa/inet.h>
+#include <string.h>
+
+#define MAGIC_BYTES_LEN 8
+#define MAGIC_BYTES     "farbfeld"
+#define PIXEL_BYTES     8
+#define CHANNEL_BYTES   2
+#define R_POS           0
+#define G_POS           2
+#define B_POS           4
+#define A_POS           6
+
+struct farbfeld_header {
+    uint8_t magic[MAGIC_BYTES_LEN];
+    uint32_t width;
+    uint32_t height;
+};
+
+uint32_t ff_size(struct farbfeld_header header)
+{
+    return sizeof(struct farbfeld_header) +
+        header.width * header.height * sizeof(argb_t) * CHANNEL_BYTES;
+}
+
+enum loader_status decode_ff(struct image* ctx, const uint8_t* data,
+                             size_t size)
+{
+
+    if (size < sizeof(struct farbfeld_header)) {
+        return ldr_unsupported;
+    }
+
+    if (memcmp(data, MAGIC_BYTES, MAGIC_BYTES_LEN) != 0) {
+        return ldr_unsupported;
+    }
+
+    uint32_t width = *(const uint32_t*)&data[MAGIC_BYTES_LEN];
+    width = htonl(width);
+    uint32_t height = *(const uint32_t*)&data[MAGIC_BYTES_LEN + sizeof(width)];
+    height = htonl(height);
+
+    const struct farbfeld_header header = { MAGIC_BYTES, width, height };
+
+    if (ff_size(header) > size) {
+        return ldr_fmterror;
+    }
+
+    ctx->alpha = true;
+
+    if (!image_allocate_frame(ctx, header.width, header.height)) {
+        return ldr_fmterror;
+    }
+
+    struct pixmap* pm = &ctx->frames[0].pm;
+
+    size_t imax = min(size, ff_size(header));
+    for (size_t i = sizeof(struct farbfeld_header); i < imax;
+         i = i + PIXEL_BYTES) {
+        argb_t pixel = ARGB(data[i + A_POS], data[i + R_POS], data[i + G_POS],
+                            data[i + B_POS]);
+        pm->data[(i - sizeof(struct farbfeld_header)) / PIXEL_BYTES] = pixel;
+    }
+
+    image_set_format(ctx, "farbfeld");
+
+    return ldr_success;
+}

src/loader.c

@@ -29,7 +29,7 @@
     enum loader_status LOADER_FUNCTION(name)(struct image * ctx, \
                                              const uint8_t* data, size_t size)
 
-const char* supported_formats = "bmp, pnm, tga"
+const char* supported_formats = "bmp, pnm, tga, ff"
 #ifdef HAVE_LIBJPEG
                                 ", jpeg"
 #endif
@@ -70,6 +70,7 @@ LOADER_DECLARE(bmp);
 LOADER_DECLARE(pnm);
 LOADER_DECLARE(qoi);
 LOADER_DECLARE(tga);
+LOADER_DECLARE(ff);
 #ifdef HAVE_LIBEXR
 LOADER_DECLARE(exr);
 #endif
@@ -134,7 +135,7 @@ static const image_decoder decoders[] = {
 #ifdef HAVE_LIBTIFF
     &LOADER_FUNCTION(tiff),
 #endif
-    &LOADER_FUNCTION(qoi),  &LOADER_FUNCTION(tga),
+    &LOADER_FUNCTION(qoi),  &LOADER_FUNCTION(ff), &LOADER_FUNCTION(tga)
 };
 
 /** Background thread loader queue. */

test/loader_test.cpp

@@ -60,6 +60,7 @@ TEST_LOADER(bmp);
 TEST_LOADER(pnm);
 TEST_LOADER(qoi);
 TEST_LOADER(tga);
+TEST_LOADER(ff);
 #ifdef HAVE_LIBEXR
 // TEST_LOADER(exr);
 #endif

test/meson.build

@@ -21,6 +21,7 @@ sources = [
   '../src/formats/pnm.c',
   '../src/formats/qoi.c',
   '../src/formats/tga.c',
+  '../src/formats/ff.c',
 ]
 if exif.found()
   sources += ['exif_test.cpp', '../src/exif.c']