commit 8d902026dc45af7b239fc6f68096a3dd31279dc9
author Katarina Behrens <Katarina.Behrens@cib.de> Thu May 02 18:24:10 2019 +0200
committer Caolán McNamara <caolanm@redhat.com> Fri May 03 17:09:08 2019 +0200
tree 5108b1ae91de0c590b9f611c1e1c4113812baa16
parent f6e663e4bb725102ebcff03cd0fea5ded9d8bc10

tdf#120585: use applyColor and make it transparency-aware

An overloaded drawPolyPolygon for zero transparency case used to
exist and it used applyColor to fill cairo path. It was removed
by commit 7034311dce663c895577267110baadbec312d491 and the new
transparency-aware drawPolyPolygon missed cairo_set_operator call
that is present in applyColor. This works OK most of the time
but breaks sometimes when no transparency (~no antialiasing)
is involved.

To fix that add transparency argument to applyColor and use it
where applicable

Change-Id: Ib1b077e38e7f5d30778434d45be67284407a7d16
Reviewed-on: https://gerrit.libreoffice.org/71700
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/headless/svpgdi.cxx

diff --git a/vcl/headless/svpgdi.cxx b/vcl/headless/svpgdi.cxx
index 6f70ec6..74c27e9 100644
--- a/vcl/headless/svpgdi.cxx
+++ b/vcl/headless/svpgdi.cxx
@@ -548,7 +548,7 @@ bool SvpSalGraphics::drawAlphaRect(long nX, long nY, long nWidth, long nHeight, 
    cairo_t* cr = getCairoContext(false);
    clipRegion(cr);

    const double fTransparency = (100 - nTransparency) * (1.0/100);
    const double fTransparency = nTransparency * (1.0/100);

    // To make releaseCairoContext work, use empty extents
    basegfx::B2DRange extents;
@@ -557,10 +557,7 @@ bool SvpSalGraphics::drawAlphaRect(long nX, long nY, long nWidth, long nHeight, 

    if (bHasFill)
    {
        cairo_set_source_rgba(cr, m_aFillColor.GetRed()/255.0,
                                  m_aFillColor.GetGreen()/255.0,
                                  m_aFillColor.GetBlue()/255.0,
                                  fTransparency);
        applyColor(cr, m_aFillColor, fTransparency);

        // set FillDamage
        extents = getClippedFillDamage(cr);
@@ -576,10 +573,7 @@ bool SvpSalGraphics::drawAlphaRect(long nX, long nY, long nWidth, long nHeight, 
        cairo_matrix_init_translate(&aMatrix, 0.5, 0.5);
        cairo_set_matrix(cr, &aMatrix);

        cairo_set_source_rgba(cr, m_aLineColor.GetRed()/255.0,
                                  m_aLineColor.GetGreen()/255.0,
                                  m_aLineColor.GetBlue()/255.0,
                                  fTransparency);
        applyColor(cr, m_aLineColor, fTransparency);

        // expand with possible StrokeDamage
        extents.expand(getClippedStrokeDamage(cr));
@@ -1451,11 +1445,7 @@ bool SvpSalGraphics::drawPolyPolygon(

    if (bHasFill)
    {
        cairo_set_source_rgba(cr, m_aFillColor.GetRed()/255.0,
                                  m_aFillColor.GetGreen()/255.0,
                                  m_aFillColor.GetBlue()/255.0,
                                  1.0-fTransparency);

        applyColor(cr, m_aFillColor, fTransparency);
        // Get FillDamage (will be extended for LineDamage below)
        extents = getClippedFillDamage(cr);

@@ -1469,12 +1459,7 @@ bool SvpSalGraphics::drawPolyPolygon(
        cairo_matrix_init_translate(&aMatrix, 0.5, 0.5);
        cairo_set_matrix(cr, &aMatrix);

        // Note: Other methods use applyColor(...) to set the Color. That
        // seems to do some more. Maybe it should be used here, too (?)
        cairo_set_source_rgba(cr, m_aLineColor.GetRed()/255.0,
                                  m_aLineColor.GetGreen()/255.0,
                                  m_aLineColor.GetBlue()/255.0,
                                  1.0-fTransparency);
        applyColor(cr, m_aLineColor, fTransparency);

        // expand with possible StrokeDamage
        extents.expand(getClippedStrokeDamage(cr));
@@ -1490,14 +1475,14 @@ bool SvpSalGraphics::drawPolyPolygon(
    return true;
}

void SvpSalGraphics::applyColor(cairo_t *cr, Color aColor)
void SvpSalGraphics::applyColor(cairo_t *cr, Color aColor, double fTransparency)
{
    if (cairo_surface_get_content(m_pSurface) == CAIRO_CONTENT_COLOR_ALPHA)
    {
        cairo_set_source_rgba(cr, aColor.GetRed()/255.0,
                                  aColor.GetGreen()/255.0,
                                  aColor.GetBlue()/255.0,
                                  1.0);
                                  1.0 - fTransparency);
    }
    else
    {

vcl/inc/headless/svpgdi.hxx

diff --git a/vcl/inc/headless/svpgdi.hxx b/vcl/inc/headless/svpgdi.hxx
index 51b53f7..73d80da 100644
--- a/vcl/inc/headless/svpgdi.hxx
+++ b/vcl/inc/headless/svpgdi.hxx
@@ -126,7 +126,7 @@ public:

private:
    void invert(const basegfx::B2DPolygon &rPoly, SalInvert nFlags);
    void applyColor(cairo_t *cr, Color rColor);
    void applyColor(cairo_t *cr, Color rColor, double fTransparency = 0.0);

protected:
    vcl::Region                         m_aClipRegion;