QskBasicLinesNode completed

src/nodes/QskBasicLinesNode.cpp

@@ -13,6 +13,21 @@ QSK_QT_PRIVATE_BEGIN
 #include <private/qsgnode_p.h>
 QSK_QT_PRIVATE_END
 
+static inline QVector4D qskColorVector( const QColor& c, qreal opacity)
+{
+    const auto a = c.alphaF() * opacity;
+    return QVector4D( c.redF() * a, c.greenF() * a, c.blueF() * a, a );
+}
+
+static inline QVector2D qskOrigin(
+    const QRect& rect, Qt::Orientations orientations )
+{
+    return QVector2D(
+        ( orientations & Qt::Horizontal ) ? 0.5 * rect.width() : 0.0,
+        ( orientations & Qt::Vertical ) ? 0.5 * rect.height() : 0.0
+    );
+}
+
 #if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
     #include <QSGMaterialRhiShader>
     using RhiShader = QSGMaterialRhiShader;
@@ -37,7 +52,7 @@ namespace
 
         int compare( const QSGMaterial* other ) const override;
 
-        QVector4D m_color = QVector4D{ 0, 0, 0, 1 };
+        QColor m_color = QColor( 255, 255, 255 );
         Qt::Orientations m_pixelAlignment;
     };
 
@@ -72,27 +87,28 @@ namespace
                 changed = true;
             }
 
-            if ( ( matOld == nullptr ) || ( matNew->m_color != matOld->m_color ) )
+            if ( ( matOld == nullptr ) || ( matNew->m_color != matOld->m_color )
+                || state.isOpacityDirty() )
             {
-                // state.opacity() TODO ...
-                memcpy( data + 64, &matNew->m_color, 16 );
+                const auto v4 = qskColorVector( matNew->m_color, state.opacity() );
+                memcpy( data + 64, &v4, 16 );
                 changed = true;
             }
 
             if ( state.isMatrixDirty() || ( matOld == nullptr )
                 || ( matNew->m_pixelAlignment != matOld->m_pixelAlignment ) )
             {
-                const auto r = state.viewportRect();
+                /*
+                    The shaders work with coordinates in the range[-1,1]. When knowing
+                    the device coordinates corresponding to [0.0] we can scale a vertex
+                    into device coordinates.
 
-                QVector2D size;
+                    coordinates <= 0.0 indicate, that no rounding should be done.
+                 */
+                const auto origin = qskOrigin(
+                    state.viewportRect(), matNew->m_pixelAlignment );
 
-                if ( matNew->m_pixelAlignment & Qt::Horizontal )
-                    size.setX( r.width() );
-
-                if ( matNew->m_pixelAlignment & Qt::Vertical )
-                    size.setY( r.height() );
-
-                memcpy( data + 80, &size, 8 );
+                memcpy( data + 80, &origin, 8 );
                 changed = true;
             }
 
@@ -135,7 +151,7 @@ namespace
 
             m_matrixId = p->uniformLocation( "matrix" );
             m_colorId = p->uniformLocation( "color" );
-            m_sizeId = p->uniformLocation( "size" );
+            m_originId = p->uniformLocation( "origin" );
         }
 
         void updateState( const QSGMaterialShader::RenderState& state,
@@ -157,26 +173,19 @@ namespace
             {
                 auto material = static_cast< const Material* >( newMaterial );
 
-                p->setUniformValue( m_colorId, material->m_color );
+                p->setUniformValue( m_colorId,
+                    qskColorVector( material->m_color, state.opacity() ) );
 
-                const auto r = state.viewportRect();
-
-                QVector2D size;
-
-                if ( material->m_pixelAlignment & Qt::Horizontal )
-                    size.setX( r.width() );
-
-                if ( material->m_pixelAlignment & Qt::Vertical )
-                    size.setY( r.height() );
-
-                p->setUniformValue( m_sizeId, size );
+                const auto origin = qskOrigin(
+                    state.viewportRect(), material->m_pixelAlignment );;
+                p->setUniformValue( m_originId, origin );
             }
         }
 
       private:
         int m_matrixId = -1;
         int m_colorId = -1;
-        int m_sizeId = -1;
+        int m_originId = -1;
     };
 }
 
@@ -273,10 +282,7 @@ void QskBasicLinesNode::setColor( const QColor& color )
 {
     Q_D( QskBasicLinesNode );
 
-    const auto a = color.alphaF();
-
-    const QVector4D c( color.redF() * a, color.greenF() * a, color.blueF() * a, a );
-
+    const auto c = color.toRgb();
     if ( c != d->material.m_color )
     {
         d->material.m_color = c;
@@ -284,6 +290,11 @@ void QskBasicLinesNode::setColor( const QColor& color )
     }
 }
 
+QColor QskBasicLinesNode::color() const
+{
+    return d_func()->material.m_color;
+}
+
 void QskBasicLinesNode::setLineWidth( float lineWidth )
 {
     Q_D( QskBasicLinesNode );

src/nodes/QskBasicLinesNode.h

@@ -31,6 +31,7 @@ class QSK_EXPORT QskBasicLinesNode : public QSGGeometryNode
     Qt::Orientations pixelAlignment() const;
 
     void setColor( const QColor& );
+    QColor color() const;
 
     void setLineWidth( float );
     float lineWidth() const;

src/nodes/shaders/crisplines-vulkan.frag

@@ -6,7 +6,7 @@ layout( std140, binding = 0 ) uniform buf
 {
     mat4 matrix;
     vec4 color;
-    vec2 size;
+    vec2 origin;
 } ubuf;
 
 void main()

src/nodes/shaders/crisplines-vulkan.vert

@@ -6,36 +6,28 @@ layout( std140, binding = 0 ) uniform buf
 {
     mat4 matrix;
     vec4 color;
-    vec2 size;
+    vec2 origin;
 } ubuf;
 
 out gl_PerVertex { vec4 gl_Position; };
 
-float normalized( in float pos, in float scale, in float size )
-{
-    return ( ( pos / size - 0.5 ) / 0.5 ) * scale;
-}
-
-float denormalized( in float pos, in float scale, in float size )
-{
-    return ( ( pos / scale ) * 0.5 + 0.5 ) * size;
-}
-
 void main()
 {
-    gl_Position = ubuf.matrix * vertexCoord;
+    vec4 pos = ubuf.matrix * vertexCoord;
 
-    if ( ubuf.size.x > 0.0 )
+    if ( ubuf.origin.x > 0.0 )
     {
-        gl_Position.x = denormalized( gl_Position.x, gl_Position.w, ubuf.size.x );
-        gl_Position.x = round( gl_Position.x ) + 0.5;
-        gl_Position.x = normalized( gl_Position.x, gl_Position.w, ubuf.size.x );
+        pos.x = ( pos.x + 1.0 ) * ubuf.origin.x;
+        pos.x = round( pos.x ) + 0.5;
+        pos.x = pos.x / ubuf.origin.x - 1.0;
     }
 
-    if ( ubuf.size.y > 0.0 )
+    if ( ubuf.origin.y > 0.0 )
     {
-        gl_Position.y = denormalized( gl_Position.y, gl_Position.w, ubuf.size.y );
-        gl_Position.y = round( gl_Position.y ) + 0.5;
-        gl_Position.y = normalized( gl_Position.y, gl_Position.w, ubuf.size.y );
+        pos.y = ( pos.y + 1.0 ) * ubuf.origin.y;
+        pos.y = round( pos.y ) + 0.5;
+        pos.y = pos.y / ubuf.origin.y - 1.0;
     }
+
+    gl_Position = pos;
 }

src/nodes/shaders/crisplines.vert

@@ -1,17 +1,7 @@
 attribute highp vec4 in_vertex;
 uniform highp mat4 matrix;
 
-uniform lowp vec2 size;
-
-float normalized( in float pos, in float scale, in float size )
-{
-    return ( ( pos / size - 0.5 ) / 0.5 ) * scale;
-}
-
-float denormalized( in float pos, in float scale, in float size )
-{
-    return ( ( pos / scale ) * 0.5 + 0.5 ) * size;
-}
+uniform lowp vec2 origin;
 
 float round( in float v )
 {
@@ -20,19 +10,21 @@ float round( in float v )
 
 void main()
 {
-    gl_Position = matrix * in_vertex;
+    vec4 pos = matrix * in_vertex;
 
-    if ( size.x > 0.0 )
+    if ( origin.x > 0.0 )
     {
-        gl_Position.x = denormalized( gl_Position.x, gl_Position.w, size.x );
-        gl_Position.x = round( gl_Position.x ) + 0.5;
-        gl_Position.x = normalized( gl_Position.x, gl_Position.w, size.x );
+        pos.x = ( pos.x + 1.0 ) * origin.x;
+        pos.x = round( pos.x ) + 0.5;
+        pos.x = pos.x / origin.x - 1.0;
     }
 
-    if ( size.y > 0.0 )
+    if ( origin.y > 0.0 )
     {
-        gl_Position.y = denormalized( gl_Position.y, gl_Position.w, size.y );
-        gl_Position.y = round( gl_Position.y ) + 0.5;
-        gl_Position.y = normalized( gl_Position.y, gl_Position.w, size.y );
+        pos.y = ( pos.y + 1.0 ) * origin.y;
+        pos.y = round( pos.y ) + 0.5;
+        pos.y = pos.y / origin.y - 1.0;
     }
+
+    gl_Position = pos;
 }