move getPixel into CairoCommon and reuse from X11CairoSalGraphicsImpl

Change-Id: I5401cc87ec228d52d98fc65840f875cfb55e30c5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/145052
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

2 files changed, 34 insertions, 29 deletions

diff --git a/vcl/headless/CairoCommon.cxx b/vcl/headless/CairoCommon.cxx
index 5781eff048e8..39538a9f9f40 100644
--- a/vcl/headless/CairoCommon.cxx
+++ b/vcl/headless/CairoCommon.cxx
@@ -623,6 +623,39 @@ void CairoCommon::drawPixel(cairo_t* cr, basegfx::B2DRange* pExtents, const Colo
         *pExtents = getClippedFillDamage(cr);
 }
 
+Color CairoCommon::getPixel(cairo_surface_t* pSurface, tools::Long nX, tools::Long nY)
+{
+    cairo_surface_t* target
+        = cairo_surface_create_similar_image(pSurface, CAIRO_FORMAT_ARGB32, 1, 1);
+
+    cairo_t* cr = cairo_create(target);
+
+    cairo_rectangle(cr, 0, 0, 1, 1);
+    cairo_set_source_surface(cr, pSurface, -nX, -nY);
+    cairo_paint(cr);
+    cairo_destroy(cr);
+
+    cairo_surface_flush(target);
+#if !ENABLE_WASM_STRIP_PREMULTIPLY
+    vcl::bitmap::lookup_table const& unpremultiply_table = vcl::bitmap::get_unpremultiply_table();
+#endif
+    unsigned char* data = cairo_image_surface_get_data(target);
+    sal_uInt8 a = data[SVP_CAIRO_ALPHA];
+#if ENABLE_WASM_STRIP_PREMULTIPLY
+    sal_uInt8 b = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_BLUE]);
+    sal_uInt8 g = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_GREEN]);
+    sal_uInt8 r = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_RED]);
+#else
+    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]];
+#endif
+    Color aColor(ColorAlpha, a, r, g, b);
+    cairo_surface_destroy(target);
+
+    return aColor;
+}
+
 void CairoCommon::drawLine(cairo_t* cr, basegfx::B2DRange* pExtents, const Color& rLineColor,
                            bool bAntiAlias, tools::Long nX1, tools::Long nY1, tools::Long nX2,
                            tools::Long nY2)
diff --git a/vcl/headless/SvpGraphicsBackend.cxx b/vcl/headless/SvpGraphicsBackend.cxx
index 84d6aa1dcd09..efff52387575 100644
--- a/vcl/headless/SvpGraphicsBackend.cxx
+++ b/vcl/headless/SvpGraphicsBackend.cxx
@@ -566,35 +566,7 @@ void SvpGraphicsBackend::drawBitmapBuffer(const SalTwoRect& rTR, const BitmapBuf
 
 Color SvpGraphicsBackend::getPixel(tools::Long nX, tools::Long nY)
 {
-    cairo_surface_t* target
-        = cairo_surface_create_similar_image(m_rCairoCommon.m_pSurface, CAIRO_FORMAT_ARGB32, 1, 1);
-
-    cairo_t* cr = cairo_create(target);
-
-    cairo_rectangle(cr, 0, 0, 1, 1);
-    cairo_set_source_surface(cr, m_rCairoCommon.m_pSurface, -nX, -nY);
-    cairo_paint(cr);
-    cairo_destroy(cr);
-
-    cairo_surface_flush(target);
-#if !ENABLE_WASM_STRIP_PREMULTIPLY
-    vcl::bitmap::lookup_table const& unpremultiply_table = vcl::bitmap::get_unpremultiply_table();
-#endif
-    unsigned char* data = cairo_image_surface_get_data(target);
-    sal_uInt8 a = data[SVP_CAIRO_ALPHA];
-#if ENABLE_WASM_STRIP_PREMULTIPLY
-    sal_uInt8 b = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_BLUE]);
-    sal_uInt8 g = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_GREEN]);
-    sal_uInt8 r = vcl::bitmap::unpremultiply(a, data[SVP_CAIRO_RED]);
-#else
-    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]];
-#endif
-    Color aColor(ColorAlpha, a, r, g, b);
-    cairo_surface_destroy(target);
-
-    return aColor;
+    return CairoCommon::getPixel(m_rCairoCommon.m_pSurface, nX, nY);
 }
 
 void SvpGraphicsBackend::invert(tools::Long nX, tools::Long nY, tools::Long nWidth,