mutter/cogl/cogl-bitmap-fallback.c
Neil Roberts ccc3068ffd cogl-bitmap: Encapsulate the CoglBitmap even internally
The CoglBitmap struct is now only defined within cogl-bitmap.c so that
all of its members can now only be accessed with accessor
functions. To get to the data pointer for the bitmap image you must
first call _cogl_bitmap_map and later call _cogl_bitmap_unmap. The map
function takes the same arguments as cogl_pixel_array_map so that
eventually we can make a bitmap optionally internally divert to a
pixel array.

There is a _cogl_bitmap_new_from_data function which constructs a new
bitmap object and takes ownership of the data pointer. The function
gets passed a destroy callback which gets called when the bitmap is
freed. This is similar to how gdk_pixbuf_new_from_data
works. Alternatively NULL can be passed for the destroy function which
means that the caller will manage the life of the pointer (but must
guarantee that it stays alive at least until the bitmap is
freed). This mechanism is used instead of the old approach of creating
a CoglBitmap struct on the stack and manually filling in the
members. It could also later be used to create a CoglBitmap that owns
a GdkPixbuf ref so that we don't necessarily have to copy the
GdkPixbuf data when converting to a bitmap.

There is also _cogl_bitmap_new_shared. This creates a bitmap using a
reference to another CoglBitmap for the data. This is a bit of a hack
but it is needed by the atlas texture backend which wants to divert
the set_region virtual to another texture but it needs to override the
format of the bitmap to ignore the premult flag.
2010-07-15 17:24:01 +01:00

583 lines
15 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl.h"
#include "cogl-internal.h"
#include "cogl-bitmap-private.h"
#include <string.h>
/* TO rgba */
inline static void
_cogl_g_to_rgba (const guint8 *src, guint8 *dst)
{
dst[0] = src[0];
dst[1] = src[0];
dst[2] = src[0];
dst[3] = 255;
}
inline static void
_cogl_rgb_to_rgba (const guint8 *src, guint8 *dst)
{
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
dst[3] = 255;
}
inline static void
_cogl_bgr_to_rgba (const guint8 *src, guint8 *dst)
{
dst[0] = src[2];
dst[1] = src[1];
dst[2] = src[0];
dst[3] = 255;
}
inline static void
_cogl_bgra_to_rgba (const guint8 *src, guint8 *dst)
{
dst[0] = src[2];
dst[1] = src[1];
dst[2] = src[0];
dst[3] = src[3];
}
inline static void
_cogl_argb_to_rgba (const guint8 *src, guint8 *dst)
{
dst[0] = src[1];
dst[1] = src[2];
dst[2] = src[3];
dst[3] = src[0];
}
inline static void
_cogl_abgr_to_rgba (const guint8 *src, guint8 *dst)
{
dst[0] = src[3];
dst[1] = src[2];
dst[2] = src[1];
dst[3] = src[0];
}
inline static void
_cogl_rgba_to_rgba (const guint8 *src, guint8 *dst)
{
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
dst[3] = src[3];
}
/* FROM rgba */
inline static void
_cogl_rgba_to_g (const guint8 *src, guint8 *dst)
{
dst[0] = (src[0] + src[1] + src[2]) / 3;
}
inline static void
_cogl_rgba_to_rgb (const guint8 *src, guint8 *dst)
{
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
}
inline static void
_cogl_rgba_to_bgr (const guint8 *src, guint8 *dst)
{
dst[0] = src[2];
dst[1] = src[1];
dst[2] = src[0];
}
inline static void
_cogl_rgba_to_bgra (const guint8 *src, guint8 *dst)
{
dst[0] = src[2];
dst[1] = src[1];
dst[2] = src[0];
dst[3] = src[3];
}
inline static void
_cogl_rgba_to_argb (const guint8 *src, guint8 *dst)
{
dst[0] = src[3];
dst[1] = src[0];
dst[2] = src[1];
dst[3] = src[2];
}
inline static void
_cogl_rgba_to_abgr (const guint8 *src, guint8 *dst)
{
dst[0] = src[3];
dst[1] = src[2];
dst[2] = src[1];
dst[3] = src[0];
}
/* (Un)Premultiplication */
inline static void
_cogl_unpremult_alpha_0 (guint8 *dst)
{
dst[0] = 0;
dst[1] = 0;
dst[2] = 0;
dst[3] = 0;
}
inline static void
_cogl_unpremult_alpha_last (guint8 *dst)
{
guint8 alpha = dst[3];
dst[0] = (dst[0] * 255) / alpha;
dst[1] = (dst[1] * 255) / alpha;
dst[2] = (dst[2] * 255) / alpha;
}
inline static void
_cogl_unpremult_alpha_first (guint8 *dst)
{
guint8 alpha = dst[0];
dst[1] = (dst[1] * 255) / alpha;
dst[2] = (dst[2] * 255) / alpha;
dst[3] = (dst[3] * 255) / alpha;
}
/* No division form of floor((c*a + 128)/255) (I first encountered
* this in the RENDER implementation in the X server.) Being exact
* is important for a == 255 - we want to get exactly c.
*/
#define MULT(d,a,t) \
G_STMT_START { \
t = d * a + 128; \
d = ((t >> 8) + t) >> 8; \
} G_STMT_END
inline static void
_cogl_premult_alpha_last (guint8 *dst)
{
guint8 alpha = dst[3];
/* Using a separate temporary per component has given slightly better
* code generation with GCC in the past; it shouldn't do any worse in
* any case.
*/
unsigned int t1, t2, t3;
MULT(dst[0], alpha, t1);
MULT(dst[1], alpha, t2);
MULT(dst[2], alpha, t3);
}
inline static void
_cogl_premult_alpha_first (guint8 *dst)
{
guint8 alpha = dst[0];
unsigned int t1, t2, t3;
MULT(dst[1], alpha, t1);
MULT(dst[2], alpha, t2);
MULT(dst[3], alpha, t3);
}
#undef MULT
/* Use the SSE optimized version to premult four pixels at once when
it is available. The same assembler code works for x86 and x86-64
because it doesn't refer to any non-SSE registers directly */
#if defined(__SSE2__) && defined(__GNUC__) \
&& (defined(__x86_64) || defined(__i386))
#define COGL_USE_PREMULT_SSE2
#endif
#ifdef COGL_USE_PREMULT_SSE2
inline static void
_cogl_premult_alpha_last_four_pixels_sse2 (guint8 *p)
{
/* 8 copies of 128 used below */
static const gint16 eight_halves[8] __attribute__ ((aligned (16))) =
{ 128, 128, 128, 128, 128, 128, 128, 128 };
/* Mask of the rgb components of the four pixels */
static const gint8 just_rgb[16] __attribute__ ((aligned (16))) =
{ 0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00,
0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00 };
/* Each SSE register only holds two pixels because we need to work
with 16-bit intermediate values. We still do four pixels by
interleaving two registers in the hope that it will pipeline
better */
asm (/* Load eight_halves into xmm5 for later */
"movdqa (%1), %%xmm5\n"
/* Clear xmm3 */
"pxor %%xmm3, %%xmm3\n"
/* Load two pixels from p into the low half of xmm0 */
"movlps (%0), %%xmm0\n"
/* Load the next set of two pixels from p into the low half of xmm1 */
"movlps 8(%0), %%xmm1\n"
/* Unpack 8 bytes from the low quad-words in each register to 8
16-bit values */
"punpcklbw %%xmm3, %%xmm0\n"
"punpcklbw %%xmm3, %%xmm1\n"
/* Copy alpha values of the first pixel in xmm0 to all
components of the first pixel in xmm2 */
"pshuflw $255, %%xmm0, %%xmm2\n"
/* same for xmm1 and xmm3 */
"pshuflw $255, %%xmm1, %%xmm3\n"
/* The above also copies the second pixel directly so we now
want to replace the RGB components with copies of the alpha
components */
"pshufhw $255, %%xmm2, %%xmm2\n"
"pshufhw $255, %%xmm3, %%xmm3\n"
/* Multiply the rgb components by the alpha */
"pmullw %%xmm2, %%xmm0\n"
"pmullw %%xmm3, %%xmm1\n"
/* Add 128 to each component */
"paddw %%xmm5, %%xmm0\n"
"paddw %%xmm5, %%xmm1\n"
/* Copy the results to temporary registers xmm4 and xmm5 */
"movdqa %%xmm0, %%xmm4\n"
"movdqa %%xmm1, %%xmm5\n"
/* Divide the results by 256 */
"psrlw $8, %%xmm0\n"
"psrlw $8, %%xmm1\n"
/* Add the temporaries back in */
"paddw %%xmm4, %%xmm0\n"
"paddw %%xmm5, %%xmm1\n"
/* Divide again */
"psrlw $8, %%xmm0\n"
"psrlw $8, %%xmm1\n"
/* Pack the results back as bytes */
"packuswb %%xmm1, %%xmm0\n"
/* Load just_rgb into xmm3 for later */
"movdqa (%2), %%xmm3\n"
/* Reload all four pixels into xmm2 */
"movups (%0), %%xmm2\n"
/* Mask out the alpha from the results */
"andps %%xmm3, %%xmm0\n"
/* Mask out the RGB from the original four pixels */
"andnps %%xmm2, %%xmm3\n"
/* Combine the two to get the right alpha values */
"orps %%xmm3, %%xmm0\n"
/* Write to memory */
"movdqu %%xmm0, (%0)\n"
: /* no outputs */
: "r" (p), "r" (eight_halves), "r" (just_rgb)
: "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5");
}
#endif /* COGL_USE_PREMULT_SSE2 */
gboolean
_cogl_bitmap_fallback_can_convert (CoglPixelFormat src, CoglPixelFormat dst)
{
if (src == dst)
return FALSE;
switch (src & COGL_UNORDERED_MASK)
{
case COGL_PIXEL_FORMAT_G_8:
case COGL_PIXEL_FORMAT_24:
case COGL_PIXEL_FORMAT_32:
if ((dst & COGL_UNORDERED_MASK) != COGL_PIXEL_FORMAT_24 &&
(dst & COGL_UNORDERED_MASK) != COGL_PIXEL_FORMAT_32 &&
(dst & COGL_UNORDERED_MASK) != COGL_PIXEL_FORMAT_G_8)
return FALSE;
break;
default:
return FALSE;
}
return TRUE;
}
gboolean
_cogl_bitmap_fallback_can_unpremult (CoglPixelFormat format)
{
return ((format & COGL_UNORDERED_MASK) == COGL_PIXEL_FORMAT_32);
}
gboolean
_cogl_bitmap_fallback_can_premult (CoglPixelFormat format)
{
return ((format & COGL_UNORDERED_MASK) == COGL_PIXEL_FORMAT_32);
}
CoglBitmap *
_cogl_bitmap_fallback_convert (CoglBitmap *src_bmp,
CoglPixelFormat dst_format)
{
guint8 *src_data;
guint8 *dst_data;
guint8 *src;
guint8 *dst;
int src_bpp;
int dst_bpp;
int src_rowstride;
int dst_rowstride;
int x,y;
guint8 temp_rgba[4] = {0,0,0,0};
int width, height;
CoglPixelFormat src_format;
src_format = _cogl_bitmap_get_format (src_bmp);
src_rowstride = _cogl_bitmap_get_rowstride (src_bmp);
width = _cogl_bitmap_get_width (src_bmp);
height = _cogl_bitmap_get_height (src_bmp);
/* Make sure conversion supported */
if (!_cogl_bitmap_fallback_can_convert (src_format, dst_format))
return NULL;
src_data = _cogl_bitmap_map (src_bmp, COGL_BUFFER_ACCESS_READ, 0);
if (src_data == NULL)
return NULL;
src_bpp = _cogl_get_format_bpp (src_format);
dst_bpp = _cogl_get_format_bpp (dst_format);
/* Initialize destination bitmap */
dst_rowstride = sizeof(guint8) * dst_bpp * width;
/* Copy the premult bit if the new format has an alpha channel */
if ((dst_format & COGL_A_BIT))
dst_format = ((src_format & COGL_PREMULT_BIT) |
(dst_format & COGL_UNPREMULT_MASK));
/* Allocate a new buffer to hold converted data */
dst_data = g_malloc (height * dst_rowstride);
/* FIXME: Optimize */
for (y = 0; y < height; y++)
{
src = src_data + y * src_rowstride;
dst = dst_data + y * dst_rowstride;
for (x = 0; x < width; x++)
{
/* FIXME: Would be nice to at least remove this inner
* branching, but not sure it can be done without
* rewriting of the whole loop */
switch (src_format & COGL_UNPREMULT_MASK)
{
case COGL_PIXEL_FORMAT_G_8:
_cogl_g_to_rgba (src, temp_rgba); break;
case COGL_PIXEL_FORMAT_RGB_888:
_cogl_rgb_to_rgba (src, temp_rgba); break;
case COGL_PIXEL_FORMAT_BGR_888:
_cogl_bgr_to_rgba (src, temp_rgba); break;
case COGL_PIXEL_FORMAT_RGBA_8888:
_cogl_rgba_to_rgba (src, temp_rgba); break;
case COGL_PIXEL_FORMAT_BGRA_8888:
_cogl_bgra_to_rgba (src, temp_rgba); break;
case COGL_PIXEL_FORMAT_ARGB_8888:
_cogl_argb_to_rgba (src, temp_rgba); break;
case COGL_PIXEL_FORMAT_ABGR_8888:
_cogl_abgr_to_rgba (src, temp_rgba); break;
default:
break;
}
switch (dst_format & COGL_UNPREMULT_MASK)
{
case COGL_PIXEL_FORMAT_G_8:
_cogl_rgba_to_g (temp_rgba, dst); break;
case COGL_PIXEL_FORMAT_RGB_888:
_cogl_rgba_to_rgb (temp_rgba, dst); break;
case COGL_PIXEL_FORMAT_BGR_888:
_cogl_rgba_to_bgr (temp_rgba, dst); break;
case COGL_PIXEL_FORMAT_RGBA_8888:
_cogl_rgba_to_rgba (temp_rgba, dst); break;
case COGL_PIXEL_FORMAT_BGRA_8888:
_cogl_rgba_to_bgra (temp_rgba, dst); break;
case COGL_PIXEL_FORMAT_ARGB_8888:
_cogl_rgba_to_argb (temp_rgba, dst); break;
case COGL_PIXEL_FORMAT_ABGR_8888:
_cogl_rgba_to_abgr (temp_rgba, dst); break;
default:
break;
}
src += src_bpp;
dst += dst_bpp;
}
}
_cogl_bitmap_unmap (src_bmp);
return _cogl_bitmap_new_from_data (dst_data,
dst_format,
width, height, dst_rowstride,
(CoglBitmapDestroyNotify) g_free,
NULL);
}
gboolean
_cogl_bitmap_fallback_unpremult (CoglBitmap *bmp)
{
guint8 *p, *data;
int x,y;
CoglPixelFormat format;
int width, height;
int rowstride;
format = _cogl_bitmap_get_format (bmp);
width = _cogl_bitmap_get_width (bmp);
height = _cogl_bitmap_get_height (bmp);
rowstride = _cogl_bitmap_get_rowstride (bmp);
/* Make sure format supported for un-premultiplication */
if (!_cogl_bitmap_fallback_can_unpremult (format))
return FALSE;
if ((data = _cogl_bitmap_map (bmp,
COGL_BUFFER_ACCESS_READ |
COGL_BUFFER_ACCESS_WRITE,
0)) == NULL)
return FALSE;
for (y = 0; y < height; y++)
{
p = (guint8*) data + y * rowstride;
if (format & COGL_AFIRST_BIT)
{
for (x = 0; x < width; x++)
{
if (p[0] == 0)
_cogl_unpremult_alpha_0 (p);
else
_cogl_unpremult_alpha_first (p);
p += 4;
}
}
else
{
for (x = 0; x < width; x++)
{
if (p[3] == 0)
_cogl_unpremult_alpha_0 (p);
else
_cogl_unpremult_alpha_last (p);
p += 4;
}
}
}
_cogl_bitmap_unmap (bmp);
_cogl_bitmap_set_format (bmp, format & ~COGL_PREMULT_BIT);
return TRUE;
}
gboolean
_cogl_bitmap_fallback_premult (CoglBitmap *bmp)
{
guint8 *p, *data;
int x,y;
CoglPixelFormat format;
int width, height;
int rowstride;
format = _cogl_bitmap_get_format (bmp);
width = _cogl_bitmap_get_width (bmp);
height = _cogl_bitmap_get_height (bmp);
rowstride = _cogl_bitmap_get_rowstride (bmp);
/* Make sure format supported for un-premultiplication */
if (!_cogl_bitmap_fallback_can_premult (format))
return FALSE;
if ((data = _cogl_bitmap_map (bmp,
COGL_BUFFER_ACCESS_READ |
COGL_BUFFER_ACCESS_WRITE,
0)) == NULL)
return FALSE;
for (y = 0; y < height; y++)
{
p = (guint8*) data + y * rowstride;
if (format & COGL_AFIRST_BIT)
{
for (x = 0; x < width; x++)
{
_cogl_premult_alpha_first (p);
p += 4;
}
}
else
{
x = width;
#ifdef COGL_USE_PREMULT_SSE2
/* Process 4 pixels at a time */
while (x >= 4)
{
_cogl_premult_alpha_last_four_pixels_sse2 (p);
p += 4 * 4;
x -= 4;
}
/* If there are any pixels left we will fall through and
handle them below */
#endif /* COGL_USE_PREMULT_SSE2 */
while (x-- > 0)
{
_cogl_premult_alpha_last (p);
p += 4;
}
}
}
_cogl_bitmap_unmap (bmp);
_cogl_bitmap_set_format (bmp, format | COGL_PREMULT_BIT);
return TRUE;
}
CoglBitmap *
_cogl_bitmap_fallback_from_file (const char *filename)
{
/* FIXME: use jpeglib, libpng, etc. manually maybe */
return FALSE;
}