add an --enable-cairo-rgba to set the order of pixels for internal cairo

Change-Id: Ieab2ef59f63a7722bffea3273d2eeefadef47b56
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/153628
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>

config_host.mk.in

@@ -145,6 +145,7 @@ export ENABLE_AVAHI=@ENABLE_AVAHI@
 export ENABLE_BREAKPAD=@ENABLE_BREAKPAD@
 export DEFAULT_CRASHDUMP_VALUE=@DEFAULT_CRASHDUMP_VALUE@
 export ENABLE_CAIRO_CANVAS=@ENABLE_CAIRO_CANVAS@
+export ENABLE_CAIRO_RGBA=@ENABLE_CAIRO_RGBA@
 export ENABLE_CIPHER_OPENSSL_BACKEND=@ENABLE_CIPHER_OPENSSL_BACKEND@
 export ENABLE_CLUCENE=@ENABLE_CLUCENE@
 export ENABLE_LIBCMIS=@ENABLE_LIBCMIS@

config_host/config_cairo_rgba.h.in

@@ -0,0 +1,6 @@
+#ifndef CONFIG_CAIRO_RGBA_H
+#define CONFIG_CAIRO_RGBA_H
+
+#define ENABLE_CAIRO_RGBA 0
+
+#endif

configure.ac

@@ -2482,6 +2482,10 @@ AC_ARG_WITH(system-hunspell,
         [Use libhunspell already on system.]),,
     [with_system_hunspell="$with_system_libs"])
 
+libo_FUZZ_ARG_ENABLE(cairo-rgba,
+    AS_HELP_STRING([--enable-cairo-rgba],
+        [Use RGBA order, instead of default BRGA. Not possible with --with-system-cairo]))
+
 libo_FUZZ_ARG_ENABLE(zxing,
     AS_HELP_STRING([--disable-zxing],
        [Disable use of zxing external library.]))
@@ -13610,6 +13614,20 @@ fi
 AC_SUBST(USE_XINERAMA)
 AC_SUBST(XINERAMA_LINK)
 
+AC_MSG_CHECKING([whether to use non-standard RGBA32 cairo pixel order])
+if test -z "$enable_cairo_rgba" -a "$_os" = "Android"; then
+    enable_cairo_rgba=yes
+fi
+if test "$enable_cairo_rgba" = yes; then
+    AC_DEFINE(ENABLE_CAIRO_RGBA)
+    ENABLE_CAIRO_RGBA=TRUE
+    AC_MSG_RESULT([yes])
+else
+    ENABLE_CAIRO_RGBA=
+    AC_MSG_RESULT([no])
+fi
+AC_SUBST(ENABLE_CAIRO_RGBA)
+
 dnl ===================================================================
 dnl Test whether to build cairo or rely on the system version
 dnl ===================================================================
@@ -13618,7 +13636,7 @@ if test "$test_cairo" = "yes"; then
     AC_MSG_CHECKING([whether to use the system cairo])
 
     : ${with_system_cairo:=$with_system_libs}
-    if test "$with_system_cairo" = "yes"; then
+    if test "$with_system_cairo" = "yes" -a "$enable_cairo_rgba" != "yes"; then
         SYSTEM_CAIRO=TRUE
         AC_MSG_RESULT([yes])
 
@@ -14924,6 +14942,7 @@ AC_CONFIG_HEADERS([config_host/config_dconf.h])
 AC_CONFIG_HEADERS([config_host/config_eot.h])
 AC_CONFIG_HEADERS([config_host/config_extensions.h])
 AC_CONFIG_HEADERS([config_host/config_cairo_canvas.h])
+AC_CONFIG_HEADERS([config_host/config_cairo_rgba.h])
 AC_CONFIG_HEADERS([config_host/config_cxxabi.h])
 AC_CONFIG_HEADERS([config_host/config_dbus.h])
 AC_CONFIG_HEADERS([config_host/config_features.h])

desktop/source/lib/init.cxx

@@ -9,6 +9,7 @@
 
 #include <sfx2/lokhelper.hxx>
 #include <config_buildconfig.h>
+#include <config_cairo_rgba.h>
 #include <config_features.h>
 
 #include <stdio.h>
@@ -4229,7 +4230,11 @@ static void doc_paintPartTile(LibreOfficeKitDocument* pThis,
 static int doc_getTileMode(SAL_UNUSED_PARAMETER LibreOfficeKitDocument* /*pThis*/)
 {
     SetLastExceptionMsg();
+#if ENABLE_CAIRO_RGBA
+    return LOK_TILEMODE_RGBA;
+#else
     return LOK_TILEMODE_BGRA;
+#endif
 }
 
 static void doc_getDocumentSize(LibreOfficeKitDocument* pThis,

distro-configs/CPLinux-LOKit.conf

@@ -6,6 +6,7 @@
 --with-myspell-dicts
 --with-system-zlib
 --disable-poppler
+--enable-cairo-rgba
 --without-system-cairo
 --without-system-fontconfig
 --without-system-freetype

distro-configs/LibreOfficeOnline.conf

@@ -15,6 +15,7 @@
 --disable-odk
 --disable-online-update
 --disable-skia
+--enable-cairo-rgba
 --enable-pdfimport
 --disable-postgresql-sdbc
 --disable-report-builder

external/cairo/UnpackedTarball_cairo.mk

@@ -40,8 +40,7 @@ $(eval $(call gb_UnpackedTarball_add_patches,cairo,\
 ))
 endif
 
-# To be applied only when ENABLE_ANDROID_LOK is not defined
-ifeq ($(OS)$(ENABLE_ANDROID_LOK),ANDROID)
+ifeq ($(ENABLE_CAIRO_RGBA),TRUE)
 $(eval $(call gb_UnpackedTarball_add_patches,cairo,\
 	external/cairo/cairo/cairo.GL_RGBA.patch \
 ))

include/vcl/cairo.hxx

@@ -24,14 +24,20 @@
 #include <vcl/Scanline.hxx>
 #include <vcl/vclptr.hxx>
 #include <config_features.h>
+#include <config_cairo_rgba.h>
 #include <memory>
 
-//Using formats that match cairo's formats. For android we patch cairo,
-//which is internal in that case, to swap the rgb components so that
-//cairo then matches the OpenGL GL_RGBA format so we can use it there
-//where we don't have GL_BGRA support.
+// Using formats that match cairo's formats.
 // SVP_24BIT_FORMAT is used to store 24-bit images in 3-byte pixels to conserve memory.
-#if defined(ANDROID) && !HAVE_FEATURE_ANDROID_LOK
+
+/*
+ For internal cairo we have the option --enable-cairo-rgba which is potentially
+ useful for Andoid or Online to switch the rgb components. For Android cairo then
+ matches the OpenGL GL_RGBA format so we can use it there where we don't have
+ GL_BGRA support. Similarly for Online we can then use cairo's pixel data
+ without needing to swizzle it for use as a canvas ImageData.
+*/
+#if ENABLE_CAIRO_RGBA
 #define SVP_24BIT_FORMAT (ScanlineFormat::N24BitTcRgb | ScanlineFormat::TopDown)
 #define SVP_CAIRO_FORMAT (ScanlineFormat::N32BitTcRgba | ScanlineFormat::TopDown)
 #define SVP_CAIRO_BLUE 1

libreofficekit/qa/tilebench/tilebench.cxx

@@ -110,29 +110,33 @@ static void dumpTile(const char *pNameStem,
         for (int x = 0; x < nWidth; ++x)
         {
             const char* pixel = row + x * 4;
-            if (mode == LOK_TILEMODE_RGBA)
-            {
-                ofs.write(pixel, 3); // Skip alpha
-            }
-            else if (mode == LOK_TILEMODE_BGRA)
-            {
-                const int alpha = *(pixel + 3);
-                char buf[3];
-                if (alpha == 0)
-                {
-                    buf[0] = 0;
-                    buf[1] = 0;
-                    buf[2] = 0;
-                }
-                else
-                {
-                    buf[0] = (*(pixel + 2) * 255 + alpha / 2) / alpha;
-                    buf[1] = (*(pixel + 1) * 255 + alpha / 2) / alpha;
-                    buf[2] = (*(pixel + 0) * 255 + alpha / 2) / alpha;
-                }
 
-                ofs.write(buf, 3);
+            const int alpha = *(pixel + 3);
+            char buf[3];
+            if (alpha == 0)
+            {
+                buf[0] = 0;
+                buf[1] = 0;
+                buf[2] = 0;
             }
+            else
+            {
+                switch (mode)
+                {
+                    case LOK_TILEMODE_RGBA:
+                        buf[0] = (*(pixel + 0) * 255 + alpha / 2) / alpha;
+                        buf[1] = (*(pixel + 1) * 255 + alpha / 2) / alpha;
+                        buf[2] = (*(pixel + 2) * 255 + alpha / 2) / alpha;
+                        break;
+                    case LOK_TILEMODE_BGRA:
+                        buf[0] = (*(pixel + 2) * 255 + alpha / 2) / alpha;
+                        buf[1] = (*(pixel + 1) * 255 + alpha / 2) / alpha;
+                        buf[2] = (*(pixel + 0) * 255 + alpha / 2) / alpha;
+                        break;
+                }
+            }
+
+            ofs.write(buf, 3);
             if (dumpText)
             {
                 int lowResI = (pixel[0] + pixel[1] + pixel[2])/(3*16);

vcl/headless/CairoCommon.cxx

@@ -2037,7 +2037,7 @@ std::unique_ptr<BitmapBuffer> FastConvert24BitRgbTo32BitCairo(const BitmapBuffer
         sal_uInt8* pD = pDst->mpBits + y * pDst->mnScanlineSize;
         for (tools::Long x = 0; x < nWidth; ++x)
         {
-#if defined(ANDROID) && !HAVE_FEATURE_ANDROID_LOK
+#if ENABLE_CAIRO_RGBA
             static_assert((SVP_CAIRO_FORMAT & ~ScanlineFormat::TopDown)
                               == ScanlineFormat::N32BitTcRgba,
                           "Expected SVP_CAIRO_FORMAT set to N32BitTcBgra");