gdk: Make the optimized premultiply function a macro

That way, all permutations are possible.  Previously it was only useful
in the cairo renderer, which required rgba8 → premultiplied bgra8, while
the GL renderer required rgba8 → premultiplied rgba8.  Now both are
available.
This commit is contained in:
Emmanuel Gil Peyrot 2022-03-03 14:34:29 +00:00
parent cfeedcc321
commit 3a98b28ab7

View File

@ -166,29 +166,32 @@ r32g32b32a32_float_from_float (guchar *dest,
memcpy (dest, src, sizeof (float) * n * 4); memcpy (dest, src, sizeof (float) * n * 4);
} }
// This one conversion is quite important, it converts from RGBA with straight #define PREMULTIPLY_FUNC(name, R1, G1, B1, A1, R2, G2, B2, A2) \
// alpha (as found in PNG for instance) to BGRA with premultiplied alpha (the static void \
// sole cairo format available). name (guchar *dest, \
static void const guchar *src, \
r8g8b8a8_to_b8g8r8a8_premultiplied (guchar *dest, gsize n) \
const guchar *src, { \
gsize n) for (; n > 0; n--) \
{ { \
for (; n > 0; n--) guchar a = src[A1]; \
{ guint16 r = (guint16)src[R1] * a + 127; \
guchar a = src[3]; guint16 g = (guint16)src[G1] * a + 127; \
guint16 r = (guint16)src[0] * a + 127; guint16 b = (guint16)src[B1] * a + 127; \
guint16 g = (guint16)src[1] * a + 127; dest[R2] = (r + (r >> 8) + 1) >> 8; \
guint16 b = (guint16)src[2] * a + 127; dest[G2] = (g + (g >> 8) + 1) >> 8; \
dest[0] = (b + (b >> 8) + 1) >> 8; dest[B2] = (b + (b >> 8) + 1) >> 8; \
dest[1] = (g + (g >> 8) + 1) >> 8; dest[A2] = a; \
dest[2] = (r + (r >> 8) + 1) >> 8; dest += 4; \
dest[3] = a; src += 4; \
dest += 4; } \
src += 4;
}
} }
PREMULTIPLY_FUNC(r8g8b8a8_to_r8g8b8a8_premultiplied, 0, 1, 2, 3, 0, 1, 2, 3)
PREMULTIPLY_FUNC(r8g8b8a8_to_b8g8r8a8_premultiplied, 0, 1, 2, 3, 2, 1, 0, 3)
PREMULTIPLY_FUNC(r8g8b8a8_to_a8r8g8b8_premultiplied, 0, 1, 2, 3, 1, 2, 3, 0)
PREMULTIPLY_FUNC(r8g8b8a8_to_a8b8g8r8_premultiplied, 0, 1, 2, 3, 3, 2, 1, 0)
struct _GdkMemoryFormatDescription struct _GdkMemoryFormatDescription
{ {
GdkMemoryAlpha alpha; GdkMemoryAlpha alpha;
@ -498,15 +501,29 @@ gdk_memory_convert (guchar *dest_data,
const GdkMemoryFormatDescription *src_desc = &memory_formats[src_format]; const GdkMemoryFormatDescription *src_desc = &memory_formats[src_format];
float *tmp; float *tmp;
gsize y; gsize y;
void (*func) (guchar *, const guchar *, gsize) = NULL;
g_assert (dest_format < GDK_MEMORY_N_FORMATS); g_assert (dest_format < GDK_MEMORY_N_FORMATS);
g_assert (src_format < GDK_MEMORY_N_FORMATS); g_assert (src_format < GDK_MEMORY_N_FORMATS);
if (src_format == GDK_MEMORY_R8G8B8A8 && dest_format == GDK_MEMORY_B8G8R8A8_PREMULTIPLIED) if (src_format == GDK_MEMORY_R8G8B8A8 && dest_format == GDK_MEMORY_R8G8B8A8_PREMULTIPLIED)
func = r8g8b8a8_to_r8g8b8a8_premultiplied;
else if (src_format == GDK_MEMORY_B8G8R8A8 && dest_format == GDK_MEMORY_R8G8B8A8_PREMULTIPLIED)
func = r8g8b8a8_to_b8g8r8a8_premultiplied;
else if (src_format == GDK_MEMORY_R8G8B8A8 && dest_format == GDK_MEMORY_B8G8R8A8_PREMULTIPLIED)
func = r8g8b8a8_to_b8g8r8a8_premultiplied;
else if (src_format == GDK_MEMORY_B8G8R8A8 && dest_format == GDK_MEMORY_B8G8R8A8_PREMULTIPLIED)
func = r8g8b8a8_to_r8g8b8a8_premultiplied;
else if (src_format == GDK_MEMORY_R8G8B8A8 && dest_format == GDK_MEMORY_A8R8G8B8_PREMULTIPLIED)
func = r8g8b8a8_to_a8r8g8b8_premultiplied;
else if (src_format == GDK_MEMORY_B8G8R8A8 && dest_format == GDK_MEMORY_A8R8G8B8_PREMULTIPLIED)
func = r8g8b8a8_to_a8b8g8r8_premultiplied;
if (func != NULL)
{ {
for (y = 0; y < height; y++) for (y = 0; y < height; y++)
{ {
r8g8b8a8_to_b8g8r8a8_premultiplied (dest_data, src_data, width); func (dest_data, src_data, width);
src_data += src_stride; src_data += src_stride;
dest_data += dest_stride; dest_data += dest_stride;
} }