opengl: use line shader for all line drawing not just polylines

Change-Id: I9c2d5c5ca4761867a0a38cb3bc3c4973454ee992
Reviewed-on: https://gerrit.libreoffice.org/25157
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 14 insertions, 200 deletions

diff --git a/vcl/opengl/gdiimpl.cxx b/vcl/opengl/gdiimpl.cxx
index 8dc167695ec8..a92e5b3fca5e 100644
--- a/vcl/opengl/gdiimpl.cxx
+++ b/vcl/opengl/gdiimpl.cxx
@@ -583,25 +583,6 @@ bool OpenGLSalGraphicsImpl::UseSolid( SalColor nColor )
     return UseSolid( nColor, 0.0f );
 }
 
-// Like UseSolid(), but sets up for AA drawing, which uses gradients to create the AA.
-bool OpenGLSalGraphicsImpl::UseSolidAA( SalColor nColor, double fTransparency )
-{
-    if( nColor == SALCOLOR_NONE )
-        return false;
-    if( !mrParent.getAntiAliasB2DDraw())
-        return UseSolid( nColor );
-    if( !UseProgram( "textureVertexShader", "linearGradientFragmentShader" ) )
-        return false;
-    mpProgram->SetColorf( "start_color", nColor, fTransparency );
-    mpProgram->SetColorf( "end_color", nColor, 1.0f );
-    return true;
-}
-
-bool OpenGLSalGraphicsImpl::UseSolidAA( SalColor nColor )
-{
-    return UseSolidAA( nColor, 0.0 );
-}
-
 bool OpenGLSalGraphicsImpl::UseInvert( SalInvert nFlags )
 {
     OpenGLZone aZone;
@@ -715,7 +696,7 @@ void OpenGLSalGraphicsImpl::DrawLineCap(float x1, float y1, float x2, float y2,
         addVertexPair(aVertices, aExtrusionVectors, p1, normal, 1.0f);
     }
 
-    ApplyProgramMatrices(0.0f);
+    ApplyProgramMatrices(0.5f);
     mpProgram->SetExtrusionVectors(aExtrusionVectors.data());
     mpProgram->DrawArrays(GL_TRIANGLE_STRIP, aVertices);
 
@@ -727,9 +708,6 @@ void OpenGLSalGraphicsImpl::DrawLineSegment(float x1, float y1, float x2, float
     glm::vec2 p1(x1, y1);
     glm::vec2 p2(x2, y2);
 
-    if (p1.x == p2.x && p1.y == p2.y)
-        return;
-
     std::vector<GLfloat> aPoints;
     std::vector<GLfloat> aExtrusionVectors;
 
@@ -741,7 +719,7 @@ void OpenGLSalGraphicsImpl::DrawLineSegment(float x1, float y1, float x2, float
     addVertexPair(aPoints, aExtrusionVectors, p1, normal, 1.0f);
     addVertexPair(aPoints, aExtrusionVectors, p2, normal, 1.0f);
 
-    ApplyProgramMatrices(0.0f);
+    ApplyProgramMatrices(0.5f);
     mpProgram->SetExtrusionVectors(aExtrusionVectors.data());
     mpProgram->DrawArrays(GL_TRIANGLE_STRIP, aPoints);
 
@@ -935,7 +913,7 @@ void OpenGLSalGraphicsImpl::DrawPolyLine(const basegfx::B2DPolygon& rPolygon, fl
             addVertexPair(aVertices, aExtrusionVectors, p1, normal, 1.0f);
         }
 
-        ApplyProgramMatrices(0.0f);
+        ApplyProgramMatrices(0.5f);
         mpProgram->SetExtrusionVectors(aExtrusionVectors.data());
         mpProgram->DrawArrays(GL_TRIANGLE_STRIP, aVertices);
 
@@ -943,7 +921,7 @@ void OpenGLSalGraphicsImpl::DrawPolyLine(const basegfx::B2DPolygon& rPolygon, fl
     }
 }
 
-bool OpenGLSalGraphicsImpl::UseLine(SalColor nColor, double fTransparency, GLfloat fLineWidth)
+bool OpenGLSalGraphicsImpl::UseLine(SalColor nColor, double fTransparency, GLfloat fLineWidth, bool bUseAA)
 {
     if( nColor == SALCOLOR_NONE )
         return false;
@@ -953,7 +931,7 @@ bool OpenGLSalGraphicsImpl::UseLine(SalColor nColor, double fTransparency, GLflo
     mpProgram->SetUniform1f("line_width", fLineWidth);
     // The width of the feather - area we make lineary transparent in VS.
     // Good AA value is 0.5
-    mpProgram->SetUniform1f("feather", 0.5f);
+    mpProgram->SetUniform1f("feather", bUseAA ? 0.5f : 0.0f);
     // We need blending or AA won't work correctly
     mpProgram->SetBlendMode( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 #ifdef DBG_UTIL
@@ -964,170 +942,6 @@ bool OpenGLSalGraphicsImpl::UseLine(SalColor nColor, double fTransparency, GLflo
     return true;
 }
 
-void OpenGLSalGraphicsImpl::DrawLineAA( double nX1, double nY1, double nX2, double nY2 )
-{
-    OpenGLZone aZone;
-
-    if( !mrParent.getAntiAliasB2DDraw())
-        return DrawLine( nX1, nY1, nX2, nY2 );
-
-    if( nX1 == nX2 || nY1 == nY2 )
-    {   // Horizontal/vertical, no need for AA, both points have normal color.
-
-        // Still set up for the trivial "gradients", because presumably UseSolidAA() has been called.
-        GLfloat aTexCoord[4] = { 0, 1, 1, 1 };
-        mpProgram->SetTextureCoord( aTexCoord );
-        DrawLine(nX1, nY1, nX2, nY2);
-
-        return;
-    }
-    ImplDrawLineAA( nX1, nY1, nX2, nY2 );
-}
-
-void OpenGLSalGraphicsImpl::ImplDrawLineAA( double nX1, double nY1, double nX2, double nY2, bool edge )
-{
-    // Draw the line anti-aliased. Based on code with the following notice:
-    /* Drawing nearly perfect 2D line segments in OpenGL
-     * You can use this code however you want.
-     * I just hope you to cite my name and the page of this technique:
-     * http://artgrammer.blogspot.com/2011/05/drawing-nearly-perfect-2d-line-segments.html
-     * http://www.codeproject.com/KB/openGL/gllinedraw.aspx
-     *
-     * Enjoy. Chris Tsang.*/
-
-    double x1 = nX1;
-    double y1 = nY1;
-    double x2 = nX2;
-    double y2 = nY2;
-
-    // A special hack for drawing lines that are in fact AA edges of a shape. Make the line somewhat
-    // wider, but (done further below) draw the entire width as a gradient. This would be wrong for a line
-    // (too wide and seemingly less straight), but it makes the edges look smoother and the width difference
-    // is almost unnoticeable.
-    const double w = edge ? 1.4 : 1.0;
-
-    double t(0.0);
-    double R(0.0);
-    double f = w - static_cast<int>(w);
-    //determine parameters t,R
-    if ( w>=0.0 && w<1.0 )
-    {
-        t=0.05;
-        R=0.48+0.32*f;
-    }
-    else if ( w>=1.0 && w<2.0 )
-    {
-        t=0.05+f*0.33;
-        R=0.768+0.312*f;
-    }
-    else if ( w>=2.0 && w<3.0 )
-    {
-        t=0.38+f*0.58;
-        R=1.08;
-    }
-    else if ( w>=3.0 && w<4.0 )
-    {
-        t=0.96+f*0.48;
-        R=1.08;
-    }
-    else if ( w>=4.0 && w<5.0 )
-    {
-        t=1.44+f*0.46;
-        R=1.08;
-    }
-    else if ( w>=5.0 && w<6.0 )
-    {
-        t=1.9+f*0.6;
-        R=1.08;
-    }
-    else if ( w>=6.0 )
-    {
-        double ff=w-6.0;
-        t=2.5+ff*0.50;
-        R=1.08;
-    }
-
-    //determine angle of the line to horizontal
-    double tx=0,ty=0; //core thinkness of a line
-    double Rx=0,Ry=0; //fading edge of a line
-    double dx=x2-x1;
-    double dy=y2-y1;
-    if ( w < 3 )
-    {   //approximate to make things even faster
-        double m=dy/dx;
-        //and calculate tx,ty,Rx,Ry
-        if ( m>-0.4142 && m<=0.4142)
-        {
-            // -22.5< angle <= 22.5, approximate to 0 (degree)
-            tx=t*0.1; ty=t;
-            Rx=R*0.6; Ry=R;
-        }
-        else if ( m>0.4142 && m<=2.4142)
-        {
-            // 22.5< angle <= 67.5, approximate to 45 (degree)
-            tx=t*-0.7071; ty=t*0.7071;
-            Rx=R*-0.7071; Ry=R*0.7071;
-        }
-        else if ( m>2.4142 || m<=-2.4142)
-        {
-            // 67.5 < angle <=112.5, approximate to 90 (degree)
-            tx=t; ty=t*0.1;
-            Rx=R; Ry=R*0.6;
-        }
-        else if ( m>-2.4142 && m<-0.4142)
-        {
-            // 112.5 < angle < 157.5, approximate to 135 (degree)
-            tx=t*0.7071; ty=t*0.7071;
-            Rx=R*0.7071; Ry=R*0.7071;
-        }
-        else
-            assert( false );
-    }
-    else
-    { //calculate to exact
-        dx=y1-y2;
-        dy=x2-x1;
-        double L=sqrt(dx*dx+dy*dy);
-        dx/=L;
-        dy/=L;
-        tx=t*dx; ty=t*dy;
-        Rx=R*dx; Ry=R*dy;
-    }
-
-    if( edge )
-    {   // See above.
-        Rx += tx;
-        Ry += ty;
-        tx = ty = 0;
-    }
-
-    std::vector<GLfloat> vertices
-    {
-        GLfloat(x1-tx-Rx), GLfloat(y1-ty-Ry), //fading edge1
-        GLfloat(x2-tx-Rx), GLfloat(y2-ty-Ry),
-        GLfloat(x1-tx),    GLfloat(y1-ty),    //core
-        GLfloat(x2-tx),    GLfloat(y2-ty),
-        GLfloat(x1+tx),    GLfloat(y1+ty),
-        GLfloat(x2+tx),    GLfloat(y2+ty),
-        GLfloat(x1+tx+Rx), GLfloat(y1+ty+Ry), //fading edge2
-        GLfloat(x2+tx+Rx), GLfloat(y2+ty+Ry)
-    };
-
-    ApplyProgramMatrices(0.0f);
-    GLfloat aTexCoord[16] = { 0, 0, 1, 0, 2, 1, 3, 1, 4, 1, 5, 1, 6, 0, 7, 0 };
-    mpProgram->SetTextureCoord( aTexCoord );
-    mpProgram->DrawArrays(GL_TRIANGLE_STRIP, vertices);
-    CHECK_GL_ERROR();
-}
-
-void OpenGLSalGraphicsImpl::DrawEdgeAA( double nX1, double nY1, double nX2, double nY2 )
-{
-    assert( mrParent.getAntiAliasB2DDraw());
-    if( nX1 == nX2 || nY1 == nY2 )
-        return; //horizontal/vertical, no need for AA
-    ImplDrawLineAA( nX1, nY1, nX2, nY2, true );
-}
-
 void OpenGLSalGraphicsImpl::DrawConvexPolygon( sal_uInt32 nPoints, const SalPoint* pPtAry, bool blockAA )
 {
     OpenGLZone aZone;
@@ -1156,13 +970,13 @@ void OpenGLSalGraphicsImpl::DrawConvexPolygon( sal_uInt32 nPoints, const SalPoin
 #endif
         SalColor lastSolidColor = mProgramSolidColor;
         double lastSolidTransparency = mProgramSolidTransparency;
-        if( UseSolidAA( lastSolidColor, lastSolidTransparency ))
+        if (UseLine(lastSolidColor, lastSolidTransparency, 1.0f ,true))
         {
             for( i = 0; i < nPoints; ++i )
             {
                 const SalPoint& rPt1 = pPtAry[ i ];
                 const SalPoint& rPt2 = pPtAry[ ( i + 1 ) % nPoints ];
-                DrawEdgeAA( rPt1.mnX, rPt1.mnY, rPt2.mnX, rPt2.mnY );
+                DrawLineSegment(rPt1.mnX, rPt1.mnY, rPt2.mnX, rPt2.mnY);
             }
             UseSolid( lastSolidColor, lastSolidTransparency );
         }
@@ -1199,13 +1013,13 @@ void OpenGLSalGraphicsImpl::DrawConvexPolygon( const tools::Polygon& rPolygon, b
 #endif
         SalColor lastSolidColor = mProgramSolidColor;
         double lastSolidTransparency = mProgramSolidTransparency;
-        if( UseSolidAA( lastSolidColor, lastSolidTransparency ))
+        if (UseLine(lastSolidColor, lastSolidTransparency, 1.0f ,true))
         {
             for( i = 0; i < nPoints; ++i )
             {
                 const Point& rPt1 = rPolygon.GetPoint( i );
                 const Point& rPt2 = rPolygon.GetPoint(( i + 1 ) % nPoints );
-                DrawEdgeAA( rPt1.getX(), rPt1.getY(), rPt2.getX(), rPt2.getY());
+                DrawLineSegment(rPt1.getX(), rPt1.getY(), rPt2.getX(), rPt2.getY());
             }
             UseSolid( lastSolidColor, lastSolidTransparency );
         }
@@ -1249,13 +1063,13 @@ void OpenGLSalGraphicsImpl::DrawTrapezoid( const basegfx::B2DTrapezoid& trapezoi
 #endif
         SalColor lastSolidColor = mProgramSolidColor;
         double lastSolidTransparency = mProgramSolidTransparency;
-        if( UseSolidAA( lastSolidColor, lastSolidTransparency ))
+        if (UseLine(lastSolidColor, lastSolidTransparency, 1.0f ,true))
         {
             for( i = 0; i < nPoints; ++i )
             {
                 const basegfx::B2DPoint& rPt1 = rPolygon.getB2DPoint( i );
                 const basegfx::B2DPoint& rPt2 = rPolygon.getB2DPoint(( i + 1 ) % nPoints );
-                DrawEdgeAA( rPt1.getX(), rPt1.getY(), rPt2.getX(), rPt2.getY());
+                DrawLineSegment(rPt1.getX(), rPt1.getY(), rPt2.getX(), rPt2.getY());
             }
             UseSolid( lastSolidColor, lastSolidTransparency );
         }
@@ -1878,8 +1692,8 @@ void OpenGLSalGraphicsImpl::drawLine( long nX1, long nY1, long nX2, long nY2 )
     if( mnLineColor != SALCOLOR_NONE )
     {
         PreDraw( XOROption::IMPLEMENT_XOR );
-        if( UseSolidAA( mnLineColor ) )
-            DrawLineAA( nX1, nY1, nX2, nY2 );
+        if (UseLine(mnLineColor, 0.0, 1.0f, mrParent.getAntiAliasB2DDraw()))
+            DrawLineSegment(nX1, nY1, nX2, nY2);
         PostDraw();
     }
 }
@@ -1998,7 +1812,7 @@ bool OpenGLSalGraphicsImpl::drawPolyLine(
 
     PreDraw(XOROption::IMPLEMENT_XOR);
 
-    if (UseLine(mnLineColor, 0.0f, fLineWidth))
+    if (UseLine(mnLineColor, 0.0f, fLineWidth, mrParent.getAntiAliasB2DDraw()))
     {
         basegfx::B2DPolygon aPolygon(rPolygon);