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http://git.netsurf-browser.org/libnsgif.git/commit/b1775d81a7f681ce1e6dc4db4020081789995927
...tree
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- Log -----------------------------------------------------------------
commitdiff
http://git.netsurf-browser.org/libnsgif.git/commit/?id=b1775d81a7f681ce1e6dc4db4020081789995927
commit b1775d81a7f681ce1e6dc4db4020081789995927
Author: Michael Drake <t...@netsurf-browser.org>
Commit: Michael Drake <t...@netsurf-browser.org>
Tests: Update decoder to set required pixel format.
diff --git a/test/nsgif.c b/test/nsgif.c
index 76d7b8f..a32a0ef 100644
--- a/test/nsgif.c
+++ b/test/nsgif.c
@@ -272,7 +272,7 @@ int main(int argc, char *argv[])
}
/* create our gif animation */
- err = nsgif_create(&bitmap_callbacks, &gif);
+ err = nsgif_create(&bitmap_callbacks, NSGIF_BITMAP_FMT_R8G8B8A8, &gif);
if (err != NSGIF_OK) {
warning("nsgif_create", err);
return EXIT_FAILURE;
commitdiff
http://git.netsurf-browser.org/libnsgif.git/commit/?id=e1c266df7688eced5ea7eaf1df2434dc92b4ccb2
commit e1c266df7688eced5ea7eaf1df2434dc92b4ccb2
Author: Michael Drake <t...@netsurf-browser.org>
Commit: Michael Drake <t...@netsurf-browser.org>
Docs: Mention colour formats in README.
diff --git a/README.md b/README.md
index 63ccdc7..e6219aa 100644
--- a/README.md
+++ b/README.md
@@ -22,14 +22,17 @@ Using
LibNSGIF allows the client to allocate the bitmap into which the GIF is
decoded. The client can have an arbitrary bitmap structure, that is simply
a void pointer to LibNSGIF. The client must provide a callback table for
-interacting with bitmaps. This table must include as a minimum functions to
-create and destroy bitmaps, and a function to get a pointer to the bitmap's
-pixel data buffer.
+interacting with bitmaps, and the required client bitmap pixel format.
+The bitmap table must include as a minimum functions to create and destroy
+bitmaps, and a function to get a pointer to the bitmap's pixel data buffer.
+
+LibNSGIF always decodes to a 32bpp, 8 bits per channel bitmap pixel format,
+however it allows the client to control the colour component ordering.
To load a GIF, first create an nsgif object with `nsgif_create()`.
```c
- err = nsgif_create(&bitmap_callbacks, &gif);
+ err = nsgif_create(&bitmap_callbacks, NSGIF_BITMAP_FMT_R8G8B8A8, &gif);
if (err != NSGIF_OK) {
fprintf(stderr, "%s\n", nsgif_strerror(err));
// Handle error
commitdiff
http://git.netsurf-browser.org/libnsgif.git/commit/?id=193234ec4e48bb6445576e0a9a1702f55234594f
commit 193234ec4e48bb6445576e0a9a1702f55234594f
Author: Michael Drake <t...@netsurf-browser.org>
Commit: Michael Drake <t...@netsurf-browser.org>
GIF: Build colour tables using colours with client channel ordering.
diff --git a/src/gif.c b/src/gif.c
index f2a304b..6d10898 100644
--- a/src/gif.c
+++ b/src/gif.c
@@ -1052,6 +1052,7 @@ static nsgif_error nsgif__parse_image_descriptor(
static nsgif_error nsgif__colour_table_extract(
struct nsgif *gif,
uint32_t colour_table[NSGIF_MAX_COLOURS],
+ const struct nsgif_colour_layout *layout,
size_t colour_table_entries,
const uint8_t **pos,
bool decode)
@@ -1070,16 +1071,16 @@ static nsgif_error nsgif__colour_table_extract(
while (count--) {
/* Gif colour map contents are r,g,b.
*
- * We want to pack them bytewise into the
- * colour table, such that the red component
- * is in byte 0 and the alpha component is in
- * byte 3.
+ * We want to pack them bytewise into the colour table,
+ * according to the client colour layout.
*/
- *entry++ = *data++; /* r */
- *entry++ = *data++; /* g */
- *entry++ = *data++; /* b */
- *entry++ = 0xff; /* a */
+ entry[layout->r] = *data++;
+ entry[layout->g] = *data++;
+ entry[layout->b] = *data++;
+ entry[layout->a] = 0xff;
+
+ entry += sizeof(uint32_t);
}
}
@@ -1114,7 +1115,8 @@ static nsgif_error nsgif__parse_colour_table(
return NSGIF_OK;
}
- ret = nsgif__colour_table_extract(gif, gif->local_colour_table,
+ ret = nsgif__colour_table_extract(gif,
+ gif->local_colour_table, &gif->colour_layout,
2 << (frame->flags & NSGIF_COLOUR_TABLE_SIZE_MASK),
pos, decode);
if (ret != NSGIF_OK) {
@@ -1629,6 +1631,7 @@ nsgif_error nsgif_data_scan(
if (gif->global_colours) {
ret = nsgif__colour_table_extract(gif,
gif->global_colour_table,
+ &gif->colour_layout,
gif->colour_table_size,
&nsgif_data, true);
if (ret != NSGIF_OK) {
@@ -1638,15 +1641,22 @@ nsgif_error nsgif_data_scan(
gif->buf_pos = (nsgif_data - gif->buf);
} else {
/* Create a default colour table with the first two
- * colours as black and white
- */
- uint32_t *entry = gif->global_colour_table;
-
- entry[0] = 0x00000000;
- /* Force Alpha channel to opaque */
- ((uint8_t *) entry)[3] = 0xff;
-
- entry[1] = 0xffffffff;
+ * colours as black and white. */
+ uint8_t *entry = (uint8_t *)gif->global_colour_table;
+
+ /* Black */
+ entry[gif->colour_layout.r] = 0x00;
+ entry[gif->colour_layout.g] = 0x00;
+ entry[gif->colour_layout.b] = 0x00;
+ entry[gif->colour_layout.a] = 0xFF;
+
+ entry += sizeof(uint32_t);
+
+ /* White */
+ entry[gif->colour_layout.r] = 0xFF;
+ entry[gif->colour_layout.g] = 0xFF;
+ entry[gif->colour_layout.b] = 0xFF;
+ entry[gif->colour_layout.a] = 0xFF;
}
if (gif->global_colours &&
commitdiff
http://git.netsurf-browser.org/libnsgif.git/commit/?id=508160b28de4899bb86b5ca14616f01e58196e1c
commit 508160b28de4899bb86b5ca14616f01e58196e1c
Author: Michael Drake <t...@netsurf-browser.org>
Commit: Michael Drake <t...@netsurf-browser.org>
API: GIF: Take client colour layout on nsgif_create().
Map the requested layout to appropriate pixel channel offsets.
diff --git a/include/nsgif.h b/include/nsgif.h
index 5fcb608..655486b 100644
--- a/include/nsgif.h
+++ b/include/nsgif.h
@@ -231,13 +231,15 @@ const char *nsgif_strerror(nsgif_error err);
/**
* Create the NSGIF object.
*
- * \param[in] bitmap_vt Bitmap operation functions v-table.
- * \param[out] gif_out Return \ref nsgif_t object on success.
+ * \param[in] bitmap_vt Bitmap operation functions v-table.
+ * \param[in] bitmap_fmt Bitmap pixel format specification.
+ * \param[out] gif_out Return \ref nsgif_t object on success.
*
* \return NSGIF_OK on success, or appropriate error otherwise.
*/
nsgif_error nsgif_create(
const nsgif_bitmap_cb_vt *bitmap_vt,
+ nsgif_bitmap_fmt_t bitmap_fmt,
nsgif_t **gif_out);
/**
diff --git a/src/gif.c b/src/gif.c
index 287b632..f2a304b 100644
--- a/src/gif.c
+++ b/src/gif.c
@@ -40,6 +40,14 @@ typedef struct nsgif_frame {
uint32_t flags;
} nsgif_frame;
+/** Pixel format: colour component order. */
+struct nsgif_colour_layout {
+ uint8_t r; /**< Byte offset within pixel to red component. */
+ uint8_t g; /**< Byte offset within pixel to green component. */
+ uint8_t b; /**< Byte offset within pixel to blue component. */
+ uint8_t a; /**< Byte offset within pixel to alpha component. */
+};
+
/** GIF animation data */
struct nsgif {
struct nsgif_info info;
@@ -83,6 +91,8 @@ struct nsgif {
bool global_colours;
/** current colour table */
uint32_t *colour_table;
+ /** Client's colour component order. */
+ struct nsgif_colour_layout colour_layout;
/** global colour table */
uint32_t global_colour_table[NSGIF_MAX_COLOURS];
/** local colour table */
@@ -1343,8 +1353,90 @@ void nsgif_destroy(nsgif_t *gif)
free(gif);
}
+/**
+ * Check whether the host is little endian.
+ *
+ * Checks whether least significant bit is in the first byte of a `uint16_t`.
+ *
+ * \return true if host is little endian.
+ */
+static inline bool nsgif__host_is_little_endian(void)
+{
+ static const uint16_t test = 1;
+
+ return ((const uint8_t *) &test)[0] == 1;
+}
+
+static struct nsgif_colour_layout nsgif__bitmap_fmt_to_colour_layout(
+ nsgif_bitmap_fmt_t bitmap_fmt)
+{
+ bool le = nsgif__host_is_little_endian();
+
+ /* Map endian-dependant formats to byte-wise format for the host. */
+ switch (bitmap_fmt) {
+ case NSGIF_BITMAP_FMT_RGBA8888:
+ bitmap_fmt = (le) ? NSGIF_BITMAP_FMT_A8B8G8R8
+ : NSGIF_BITMAP_FMT_R8G8B8A8;
+ break;
+ case NSGIF_BITMAP_FMT_BGRA8888:
+ bitmap_fmt = (le) ? NSGIF_BITMAP_FMT_A8R8G8B8
+ : NSGIF_BITMAP_FMT_B8G8R8A8;
+ break;
+ case NSGIF_BITMAP_FMT_ARGB8888:
+ bitmap_fmt = (le) ? NSGIF_BITMAP_FMT_B8G8R8A8
+ : NSGIF_BITMAP_FMT_A8R8G8B8;
+ break;
+ case NSGIF_BITMAP_FMT_ABGR8888:
+ bitmap_fmt = (le) ? NSGIF_BITMAP_FMT_R8G8B8A8
+ : NSGIF_BITMAP_FMT_A8B8G8R8;
+ break;
+ default:
+ break;
+ }
+
+ /* Set up colour component order for bitmap format. */
+ switch (bitmap_fmt) {
+ default:
+ /* Fall through. */
+ case NSGIF_BITMAP_FMT_R8G8B8A8:
+ return (struct nsgif_colour_layout) {
+ .r = 0,
+ .g = 1,
+ .b = 2,
+ .a = 3,
+ };
+
+ case NSGIF_BITMAP_FMT_B8G8R8A8:
+ return (struct nsgif_colour_layout) {
+ .b = 0,
+ .g = 1,
+ .r = 2,
+ .a = 3,
+ };
+
+ case NSGIF_BITMAP_FMT_A8R8G8B8:
+ return (struct nsgif_colour_layout) {
+ .a = 0,
+ .r = 1,
+ .g = 2,
+ .b = 3,
+ };
+
+ case NSGIF_BITMAP_FMT_A8B8G8R8:
+ return (struct nsgif_colour_layout) {
+ .a = 0,
+ .b = 1,
+ .g = 2,
+ .r = 3,
+ };
+ }
+}
+
/* exported function documented in nsgif.h */
-nsgif_error nsgif_create(const nsgif_bitmap_cb_vt *bitmap_vt, nsgif_t
**gif_out)
+nsgif_error nsgif_create(
+ const nsgif_bitmap_cb_vt *bitmap_vt,
+ nsgif_bitmap_fmt_t bitmap_fmt,
+ nsgif_t **gif_out)
{
nsgif_t *gif;
@@ -1360,6 +1452,8 @@ nsgif_error nsgif_create(const nsgif_bitmap_cb_vt
*bitmap_vt, nsgif_t **gif_out)
gif->delay_min = 2;
gif->delay_default = 10;
+ gif->colour_layout = nsgif__bitmap_fmt_to_colour_layout(bitmap_fmt);
+
*gif_out = gif;
return NSGIF_OK;
}
commitdiff
http://git.netsurf-browser.org/libnsgif.git/commit/?id=617da7327f1247ae6930a814e065531a08cde4b5
commit 617da7327f1247ae6930a814e065531a08cde4b5
Author: Michael Drake <t...@netsurf-browser.org>
Commit: Michael Drake <t...@netsurf-browser.org>
API: Add enum for colour component order selection.
This will allow the client to choose the colour component order
for decoded bitmaps.
diff --git a/include/nsgif.h b/include/nsgif.h
index 54dcd71..5fcb608 100644
--- a/include/nsgif.h
+++ b/include/nsgif.h
@@ -99,14 +99,69 @@ typedef enum {
} nsgif_error;
/**
+ * NSGIF \ref nsgif_bitmap_t pixel format.
+ *
+ * All pixel formats are 32 bits per pixel (bpp). The different formats
+ * allow control over the ordering of the colour channels. All colour
+ * channels are 8 bits wide.
+ *
+ * Note that the GIF file format only supports an on/off mask, so the
+ * alpha (A) component (opacity) will always have a value of `0` (fully
+ * transparent) or `255` (fully opaque).
+ */
+typedef enum nsgif_bitmap_fmt {
+ /** Bite-wise RGBA: Byte order: 0xRR, 0xGG, 0xBB, 0xAA. */
+ NSGIF_BITMAP_FMT_R8G8B8A8,
+
+ /** Bite-wise BGRA: Byte order: 0xBB, 0xGG, 0xRR, 0xAA. */
+ NSGIF_BITMAP_FMT_B8G8R8A8,
+
+ /** Bite-wise ARGB: Byte order: 0xAA, 0xRR, 0xGG, 0xBB. */
+ NSGIF_BITMAP_FMT_A8R8G8B8,
+
+ /** Bite-wise ABGR: Byte order: 0xAA, 0xBB, 0xGG, 0xRR. */
+ NSGIF_BITMAP_FMT_A8B8G8R8,
+
+ /**
+ * 32-bit RGBA (0xRRGGBBAA).
+ *
+ * * On little endian host, same as \ref NSGIF_BITMAP_FMT_A8B8G8R8.
+ * * On big endian host, same as \ref NSGIF_BITMAP_FMT_R8G8B8A8.
+ */
+ NSGIF_BITMAP_FMT_RGBA8888,
+
+ /**
+ * 32-bit BGRA (0xBBGGRRAA).
+ *
+ * * On little endian host, same as \ref NSGIF_BITMAP_FMT_A8R8G8B8.
+ * * On big endian host, same as \ref NSGIF_BITMAP_FMT_B8G8R8A8.
+ */
+ NSGIF_BITMAP_FMT_BGRA8888,
+
+ /**
+ * 32-bit ARGB (0xAARRGGBB).
+ *
+ * * On little endian host, same as \ref NSGIF_BITMAP_FMT_B8G8R8A8.
+ * * On big endian host, same as \ref NSGIF_BITMAP_FMT_A8R8G8B8.
+ */
+ NSGIF_BITMAP_FMT_ARGB8888,
+
+ /**
+ * 32-bit BGRA (0xAABBGGRR).
+ *
+ * * On little endian host, same as \ref NSGIF_BITMAP_FMT_R8G8B8A8.
+ * * On big endian host, same as \ref NSGIF_BITMAP_FMT_A8B8G8R8.
+ */
+ NSGIF_BITMAP_FMT_ABGR8888,
+} nsgif_bitmap_fmt_t;
+
+/**
* Client bitmap type.
*
* These are client-created and destroyed, via the \ref bitmap callbacks,
* but they are owned by a \ref nsgif_t.
*
- * The pixel buffer is is 32bpp, treated as individual bytes in the component
- * order RR GG BB AA. For example, a 1x1 image with a single orange pixel would
- * be encoded as the following sequence of bytes: 0xff, 0x88, 0x00, 0x00.
+ * See \ref nsgif_bitmap_fmt for pixel format information.
*/
typedef void nsgif_bitmap_t;
-----------------------------------------------------------------------
Summary of changes:
README.md | 11 +++--
include/nsgif.h | 67 ++++++++++++++++++++++++--
src/gif.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++--------
test/nsgif.c | 2 +-
4 files changed, 193 insertions(+), 29 deletions(-)
diff --git a/README.md b/README.md
index 63ccdc7..e6219aa 100644
--- a/README.md
+++ b/README.md
@@ -22,14 +22,17 @@ Using
LibNSGIF allows the client to allocate the bitmap into which the GIF is
decoded. The client can have an arbitrary bitmap structure, that is simply
a void pointer to LibNSGIF. The client must provide a callback table for
-interacting with bitmaps. This table must include as a minimum functions to
-create and destroy bitmaps, and a function to get a pointer to the bitmap's
-pixel data buffer.
+interacting with bitmaps, and the required client bitmap pixel format.
+The bitmap table must include as a minimum functions to create and destroy
+bitmaps, and a function to get a pointer to the bitmap's pixel data buffer.
+
+LibNSGIF always decodes to a 32bpp, 8 bits per channel bitmap pixel format,
+however it allows the client to control the colour component ordering.
To load a GIF, first create an nsgif object with `nsgif_create()`.
```c
- err = nsgif_create(&bitmap_callbacks, &gif);
+ err = nsgif_create(&bitmap_callbacks, NSGIF_BITMAP_FMT_R8G8B8A8, &gif);
if (err != NSGIF_OK) {
fprintf(stderr, "%s\n", nsgif_strerror(err));
// Handle error
diff --git a/include/nsgif.h b/include/nsgif.h
index 54dcd71..655486b 100644
--- a/include/nsgif.h
+++ b/include/nsgif.h
@@ -99,14 +99,69 @@ typedef enum {
} nsgif_error;
/**
+ * NSGIF \ref nsgif_bitmap_t pixel format.
+ *
+ * All pixel formats are 32 bits per pixel (bpp). The different formats
+ * allow control over the ordering of the colour channels. All colour
+ * channels are 8 bits wide.
+ *
+ * Note that the GIF file format only supports an on/off mask, so the
+ * alpha (A) component (opacity) will always have a value of `0` (fully
+ * transparent) or `255` (fully opaque).
+ */
+typedef enum nsgif_bitmap_fmt {
+ /** Bite-wise RGBA: Byte order: 0xRR, 0xGG, 0xBB, 0xAA. */
+ NSGIF_BITMAP_FMT_R8G8B8A8,
+
+ /** Bite-wise BGRA: Byte order: 0xBB, 0xGG, 0xRR, 0xAA. */
+ NSGIF_BITMAP_FMT_B8G8R8A8,
+
+ /** Bite-wise ARGB: Byte order: 0xAA, 0xRR, 0xGG, 0xBB. */
+ NSGIF_BITMAP_FMT_A8R8G8B8,
+
+ /** Bite-wise ABGR: Byte order: 0xAA, 0xBB, 0xGG, 0xRR. */
+ NSGIF_BITMAP_FMT_A8B8G8R8,
+
+ /**
+ * 32-bit RGBA (0xRRGGBBAA).
+ *
+ * * On little endian host, same as \ref NSGIF_BITMAP_FMT_A8B8G8R8.
+ * * On big endian host, same as \ref NSGIF_BITMAP_FMT_R8G8B8A8.
+ */
+ NSGIF_BITMAP_FMT_RGBA8888,
+
+ /**
+ * 32-bit BGRA (0xBBGGRRAA).
+ *
+ * * On little endian host, same as \ref NSGIF_BITMAP_FMT_A8R8G8B8.
+ * * On big endian host, same as \ref NSGIF_BITMAP_FMT_B8G8R8A8.
+ */
+ NSGIF_BITMAP_FMT_BGRA8888,
+
+ /**
+ * 32-bit ARGB (0xAARRGGBB).
+ *
+ * * On little endian host, same as \ref NSGIF_BITMAP_FMT_B8G8R8A8.
+ * * On big endian host, same as \ref NSGIF_BITMAP_FMT_A8R8G8B8.
+ */
+ NSGIF_BITMAP_FMT_ARGB8888,
+
+ /**
+ * 32-bit BGRA (0xAABBGGRR).
+ *
+ * * On little endian host, same as \ref NSGIF_BITMAP_FMT_R8G8B8A8.
+ * * On big endian host, same as \ref NSGIF_BITMAP_FMT_A8B8G8R8.
+ */
+ NSGIF_BITMAP_FMT_ABGR8888,
+} nsgif_bitmap_fmt_t;
+
+/**
* Client bitmap type.
*
* These are client-created and destroyed, via the \ref bitmap callbacks,
* but they are owned by a \ref nsgif_t.
*
- * The pixel buffer is is 32bpp, treated as individual bytes in the component
- * order RR GG BB AA. For example, a 1x1 image with a single orange pixel would
- * be encoded as the following sequence of bytes: 0xff, 0x88, 0x00, 0x00.
+ * See \ref nsgif_bitmap_fmt for pixel format information.
*/
typedef void nsgif_bitmap_t;
@@ -176,13 +231,15 @@ const char *nsgif_strerror(nsgif_error err);
/**
* Create the NSGIF object.
*
- * \param[in] bitmap_vt Bitmap operation functions v-table.
- * \param[out] gif_out Return \ref nsgif_t object on success.
+ * \param[in] bitmap_vt Bitmap operation functions v-table.
+ * \param[in] bitmap_fmt Bitmap pixel format specification.
+ * \param[out] gif_out Return \ref nsgif_t object on success.
*
* \return NSGIF_OK on success, or appropriate error otherwise.
*/
nsgif_error nsgif_create(
const nsgif_bitmap_cb_vt *bitmap_vt,
+ nsgif_bitmap_fmt_t bitmap_fmt,
nsgif_t **gif_out);
/**
diff --git a/src/gif.c b/src/gif.c
index 287b632..6d10898 100644
--- a/src/gif.c
+++ b/src/gif.c
@@ -40,6 +40,14 @@ typedef struct nsgif_frame {
uint32_t flags;
} nsgif_frame;
+/** Pixel format: colour component order. */
+struct nsgif_colour_layout {
+ uint8_t r; /**< Byte offset within pixel to red component. */
+ uint8_t g; /**< Byte offset within pixel to green component. */
+ uint8_t b; /**< Byte offset within pixel to blue component. */
+ uint8_t a; /**< Byte offset within pixel to alpha component. */
+};
+
/** GIF animation data */
struct nsgif {
struct nsgif_info info;
@@ -83,6 +91,8 @@ struct nsgif {
bool global_colours;
/** current colour table */
uint32_t *colour_table;
+ /** Client's colour component order. */
+ struct nsgif_colour_layout colour_layout;
/** global colour table */
uint32_t global_colour_table[NSGIF_MAX_COLOURS];
/** local colour table */
@@ -1042,6 +1052,7 @@ static nsgif_error nsgif__parse_image_descriptor(
static nsgif_error nsgif__colour_table_extract(
struct nsgif *gif,
uint32_t colour_table[NSGIF_MAX_COLOURS],
+ const struct nsgif_colour_layout *layout,
size_t colour_table_entries,
const uint8_t **pos,
bool decode)
@@ -1060,16 +1071,16 @@ static nsgif_error nsgif__colour_table_extract(
while (count--) {
/* Gif colour map contents are r,g,b.
*
- * We want to pack them bytewise into the
- * colour table, such that the red component
- * is in byte 0 and the alpha component is in
- * byte 3.
+ * We want to pack them bytewise into the colour table,
+ * according to the client colour layout.
*/
- *entry++ = *data++; /* r */
- *entry++ = *data++; /* g */
- *entry++ = *data++; /* b */
- *entry++ = 0xff; /* a */
+ entry[layout->r] = *data++;
+ entry[layout->g] = *data++;
+ entry[layout->b] = *data++;
+ entry[layout->a] = 0xff;
+
+ entry += sizeof(uint32_t);
}
}
@@ -1104,7 +1115,8 @@ static nsgif_error nsgif__parse_colour_table(
return NSGIF_OK;
}
- ret = nsgif__colour_table_extract(gif, gif->local_colour_table,
+ ret = nsgif__colour_table_extract(gif,
+ gif->local_colour_table, &gif->colour_layout,
2 << (frame->flags & NSGIF_COLOUR_TABLE_SIZE_MASK),
pos, decode);
if (ret != NSGIF_OK) {
@@ -1343,8 +1355,90 @@ void nsgif_destroy(nsgif_t *gif)
free(gif);
}
+/**
+ * Check whether the host is little endian.
+ *
+ * Checks whether least significant bit is in the first byte of a `uint16_t`.
+ *
+ * \return true if host is little endian.
+ */
+static inline bool nsgif__host_is_little_endian(void)
+{
+ static const uint16_t test = 1;
+
+ return ((const uint8_t *) &test)[0] == 1;
+}
+
+static struct nsgif_colour_layout nsgif__bitmap_fmt_to_colour_layout(
+ nsgif_bitmap_fmt_t bitmap_fmt)
+{
+ bool le = nsgif__host_is_little_endian();
+
+ /* Map endian-dependant formats to byte-wise format for the host. */
+ switch (bitmap_fmt) {
+ case NSGIF_BITMAP_FMT_RGBA8888:
+ bitmap_fmt = (le) ? NSGIF_BITMAP_FMT_A8B8G8R8
+ : NSGIF_BITMAP_FMT_R8G8B8A8;
+ break;
+ case NSGIF_BITMAP_FMT_BGRA8888:
+ bitmap_fmt = (le) ? NSGIF_BITMAP_FMT_A8R8G8B8
+ : NSGIF_BITMAP_FMT_B8G8R8A8;
+ break;
+ case NSGIF_BITMAP_FMT_ARGB8888:
+ bitmap_fmt = (le) ? NSGIF_BITMAP_FMT_B8G8R8A8
+ : NSGIF_BITMAP_FMT_A8R8G8B8;
+ break;
+ case NSGIF_BITMAP_FMT_ABGR8888:
+ bitmap_fmt = (le) ? NSGIF_BITMAP_FMT_R8G8B8A8
+ : NSGIF_BITMAP_FMT_A8B8G8R8;
+ break;
+ default:
+ break;
+ }
+
+ /* Set up colour component order for bitmap format. */
+ switch (bitmap_fmt) {
+ default:
+ /* Fall through. */
+ case NSGIF_BITMAP_FMT_R8G8B8A8:
+ return (struct nsgif_colour_layout) {
+ .r = 0,
+ .g = 1,
+ .b = 2,
+ .a = 3,
+ };
+
+ case NSGIF_BITMAP_FMT_B8G8R8A8:
+ return (struct nsgif_colour_layout) {
+ .b = 0,
+ .g = 1,
+ .r = 2,
+ .a = 3,
+ };
+
+ case NSGIF_BITMAP_FMT_A8R8G8B8:
+ return (struct nsgif_colour_layout) {
+ .a = 0,
+ .r = 1,
+ .g = 2,
+ .b = 3,
+ };
+
+ case NSGIF_BITMAP_FMT_A8B8G8R8:
+ return (struct nsgif_colour_layout) {
+ .a = 0,
+ .b = 1,
+ .g = 2,
+ .r = 3,
+ };
+ }
+}
+
/* exported function documented in nsgif.h */
-nsgif_error nsgif_create(const nsgif_bitmap_cb_vt *bitmap_vt, nsgif_t
**gif_out)
+nsgif_error nsgif_create(
+ const nsgif_bitmap_cb_vt *bitmap_vt,
+ nsgif_bitmap_fmt_t bitmap_fmt,
+ nsgif_t **gif_out)
{
nsgif_t *gif;
@@ -1360,6 +1454,8 @@ nsgif_error nsgif_create(const nsgif_bitmap_cb_vt
*bitmap_vt, nsgif_t **gif_out)
gif->delay_min = 2;
gif->delay_default = 10;
+ gif->colour_layout = nsgif__bitmap_fmt_to_colour_layout(bitmap_fmt);
+
*gif_out = gif;
return NSGIF_OK;
}
@@ -1535,6 +1631,7 @@ nsgif_error nsgif_data_scan(
if (gif->global_colours) {
ret = nsgif__colour_table_extract(gif,
gif->global_colour_table,
+ &gif->colour_layout,
gif->colour_table_size,
&nsgif_data, true);
if (ret != NSGIF_OK) {
@@ -1544,15 +1641,22 @@ nsgif_error nsgif_data_scan(
gif->buf_pos = (nsgif_data - gif->buf);
} else {
/* Create a default colour table with the first two
- * colours as black and white
- */
- uint32_t *entry = gif->global_colour_table;
-
- entry[0] = 0x00000000;
- /* Force Alpha channel to opaque */
- ((uint8_t *) entry)[3] = 0xff;
-
- entry[1] = 0xffffffff;
+ * colours as black and white. */
+ uint8_t *entry = (uint8_t *)gif->global_colour_table;
+
+ /* Black */
+ entry[gif->colour_layout.r] = 0x00;
+ entry[gif->colour_layout.g] = 0x00;
+ entry[gif->colour_layout.b] = 0x00;
+ entry[gif->colour_layout.a] = 0xFF;
+
+ entry += sizeof(uint32_t);
+
+ /* White */
+ entry[gif->colour_layout.r] = 0xFF;
+ entry[gif->colour_layout.g] = 0xFF;
+ entry[gif->colour_layout.b] = 0xFF;
+ entry[gif->colour_layout.a] = 0xFF;
}
if (gif->global_colours &&
diff --git a/test/nsgif.c b/test/nsgif.c
index 76d7b8f..a32a0ef 100644
--- a/test/nsgif.c
+++ b/test/nsgif.c
@@ -272,7 +272,7 @@ int main(int argc, char *argv[])
}
/* create our gif animation */
- err = nsgif_create(&bitmap_callbacks, &gif);
+ err = nsgif_create(&bitmap_callbacks, NSGIF_BITMAP_FMT_R8G8B8A8, &gif);
if (err != NSGIF_OK) {
warning("nsgif_create", err);
return EXIT_FAILURE;
--
NetSurf GIF Decoder
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