From 57b8a021ad19fb400c2b91f115e53dd41cbd8550 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Caol=C3=A1n=20McNamara?= <caolanm@redhat.com>
Date: Fri, 30 Nov 2018 17:03:11 +0000
Subject: [PATCH] Related: tdf#121721 use premultiply unpremultiply tables
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for tdf#121721 this brings the time down between pressing F5 and seeing the
image from 4 seconds to 1.4 seconds
Change-Id: I8e7f15e5126218b040e96f9143827ff788b4fb51
Reviewed-on: https://gerrit.libreoffice.org/64403
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
---
vcl/headless/svpgdi.cxx | 74 ++++++++++++++++++++++++++++++++---------
1 file changed, 58 insertions(+), 16 deletions(-)
diff --git a/vcl/headless/svpgdi.cxx b/vcl/headless/svpgdi.cxx
index f4ef3b21fe33..011d698d0fcb 100644
--- a/vcl/headless/svpgdi.cxx
+++ b/vcl/headless/svpgdi.cxx
@@ -1213,7 +1213,7 @@ void SvpSalGraphics::drawBitmap( const SalTwoRect& rTR,
static sal_uInt8 unpremultiply(sal_uInt8 c, sal_uInt8 a)
{
- return (a > 0) ? (c * 255 + a / 2) / a : 0;
+ return (a == 0) ? 0 : (c * 255 + a / 2) / a;
}
static sal_uInt8 premultiply(sal_uInt8 c, sal_uInt8 a)
@@ -1221,6 +1221,40 @@ static sal_uInt8 premultiply(sal_uInt8 c, sal_uInt8 a)
return (c * a + 127) / 255;
}
+typedef sal_uInt8 (*lookup_table)[256];
+
+static lookup_table get_unpremultiply_table()
+{
+ static bool inited;
+ static sal_uInt8 unpremultiply_table[256][256];
+
+ if (!inited)
+ {
+ for (int a = 0; a < 256; ++a)
+ for (int c = 0; c < 256; ++c)
+ unpremultiply_table[a][c] = unpremultiply(c, a);
+ inited = true;
+ }
+
+ return unpremultiply_table;
+}
+
+static lookup_table get_premultiply_table()
+{
+ static bool inited;
+ static sal_uInt8 premultiply_table[256][256];
+
+ if (!inited)
+ {
+ for (int a = 0; a < 256; ++a)
+ for (int c = 0; c < 256; ++c)
+ premultiply_table[a][c] = premultiply(c, a);
+ inited = true;
+ }
+
+ return premultiply_table;
+}
+
void SvpSalGraphics::drawMask( const SalTwoRect& rTR,
const SalBitmap& rSalBitmap,
Color nMaskColor )
@@ -1235,15 +1269,17 @@ void SvpSalGraphics::drawMask( const SalTwoRect& rTR,
}
sal_Int32 nStride;
unsigned char *mask_data = aSurface.getBits(nStride);
+ lookup_table unpremultiply_table = get_unpremultiply_table();
for (sal_Int32 y = rTR.mnSrcY ; y < rTR.mnSrcY + rTR.mnSrcHeight; ++y)
{
unsigned char *row = mask_data + (nStride*y);
unsigned char *data = row + (rTR.mnSrcX * 4);
for (sal_Int32 x = rTR.mnSrcX; x < rTR.mnSrcX + rTR.mnSrcWidth; ++x)
{
- sal_uInt8 b = unpremultiply(data[SVP_CAIRO_BLUE], data[SVP_CAIRO_ALPHA]);
- sal_uInt8 g = unpremultiply(data[SVP_CAIRO_GREEN], data[SVP_CAIRO_ALPHA]);
- sal_uInt8 r = unpremultiply(data[SVP_CAIRO_RED], data[SVP_CAIRO_ALPHA]);
+ sal_uInt8 a = data[SVP_CAIRO_ALPHA];
+ sal_uInt8 b = unpremultiply_table[a][data[SVP_CAIRO_BLUE]];
+ sal_uInt8 g = unpremultiply_table[a][data[SVP_CAIRO_GREEN]];
+ sal_uInt8 r = unpremultiply_table[a][data[SVP_CAIRO_RED]];
if (r == 0 && g == 0 && b == 0)
{
data[0] = nMaskColor.GetBlue();
@@ -1337,10 +1373,12 @@ Color SvpSalGraphics::getPixel( long nX, long nY )
cairo_destroy(cr);
cairo_surface_flush(target);
+ lookup_table unpremultiply_table = get_unpremultiply_table();
unsigned char *data = cairo_image_surface_get_data(target);
- sal_uInt8 b = unpremultiply(data[SVP_CAIRO_BLUE], data[SVP_CAIRO_ALPHA]);
- sal_uInt8 g = unpremultiply(data[SVP_CAIRO_GREEN], data[SVP_CAIRO_ALPHA]);
- sal_uInt8 r = unpremultiply(data[SVP_CAIRO_RED], data[SVP_CAIRO_ALPHA]);
+ sal_uInt8 a = data[SVP_CAIRO_ALPHA];
+ sal_uInt8 b = unpremultiply_table[a][data[SVP_CAIRO_BLUE]];
+ sal_uInt8 g = unpremultiply_table[a][data[SVP_CAIRO_GREEN]];
+ sal_uInt8 r = unpremultiply_table[a][data[SVP_CAIRO_RED]];
Color nRet = Color(r, g, b);
cairo_surface_destroy(target);
@@ -1592,6 +1630,8 @@ void SvpSalGraphics::releaseCairoContext(cairo_t* cr, bool bXorModeAllowed, cons
sal_Int32 nUnscaledExtentsRight = nExtentsRight * m_fScale;
sal_Int32 nUnscaledExtentsTop = nExtentsTop * m_fScale;
sal_Int32 nUnscaledExtentsBottom = nExtentsBottom * m_fScale;
+ lookup_table unpremultiply_table = get_unpremultiply_table();
+ lookup_table premultiply_table = get_premultiply_table();
for (sal_Int32 y = nUnscaledExtentsTop; y < nUnscaledExtentsBottom; ++y)
{
unsigned char *true_row = target_surface_data + (nStride*y);
@@ -1600,15 +1640,17 @@ void SvpSalGraphics::releaseCairoContext(cairo_t* cr, bool bXorModeAllowed, cons
unsigned char *xor_data = xor_row + (nUnscaledExtentsLeft * 4);
for (sal_Int32 x = nUnscaledExtentsLeft; x < nUnscaledExtentsRight; ++x)
{
- sal_uInt8 b = unpremultiply(true_data[SVP_CAIRO_BLUE], true_data[SVP_CAIRO_ALPHA]) ^
- unpremultiply(xor_data[SVP_CAIRO_BLUE], xor_data[SVP_CAIRO_ALPHA]);
- sal_uInt8 g = unpremultiply(true_data[SVP_CAIRO_GREEN], true_data[SVP_CAIRO_ALPHA]) ^
- unpremultiply(xor_data[SVP_CAIRO_GREEN], xor_data[SVP_CAIRO_ALPHA]);
- sal_uInt8 r = unpremultiply(true_data[SVP_CAIRO_RED], true_data[SVP_CAIRO_ALPHA]) ^
- unpremultiply(xor_data[SVP_CAIRO_RED], xor_data[SVP_CAIRO_ALPHA]);
- true_data[0] = premultiply(b, true_data[SVP_CAIRO_ALPHA]);
- true_data[1] = premultiply(g, true_data[SVP_CAIRO_ALPHA]);
- true_data[2] = premultiply(r, true_data[SVP_CAIRO_ALPHA]);
+ sal_uInt8 a = true_data[SVP_CAIRO_ALPHA];
+ sal_uInt8 xor_a = xor_data[SVP_CAIRO_ALPHA];
+ sal_uInt8 b = unpremultiply_table[a][true_data[SVP_CAIRO_BLUE]] ^
+ unpremultiply_table[xor_a][xor_data[SVP_CAIRO_BLUE]];
+ sal_uInt8 g = unpremultiply_table[a][true_data[SVP_CAIRO_GREEN]] ^
+ unpremultiply_table[xor_a][xor_data[SVP_CAIRO_GREEN]];
+ sal_uInt8 r = unpremultiply_table[a][true_data[SVP_CAIRO_RED]] ^
+ unpremultiply_table[xor_a][xor_data[SVP_CAIRO_RED]];
+ true_data[SVP_CAIRO_BLUE] = premultiply_table[a][b];
+ true_data[SVP_CAIRO_GREEN] = premultiply_table[a][g];
+ true_data[SVP_CAIRO_RED] = premultiply_table[a][r];
true_data+=4;
xor_data+=4;
}
--
2.20.1