improve alignment of marks and playpos, avoid using half empty images

src/waveform/renderers/allshader/waveformrendermark.cpp

@@ -243,14 +243,13 @@ void allshader::WaveformRenderMark::paintGL() {
         // Pixmaps are expected to have the mark stroke at the center,
         // and preferably have an odd width in order to have the stroke
         // exactly at the sample position.
-        const float markHalfWidth = pTexture->width() / devicePixelRatio / 2.f;
-        const float drawOffset = currentMarkPoint - markHalfWidth;
+        const float markWidth = pTexture->width() / devicePixelRatio;
+        const float drawOffset = currentMarkPoint + pMark->getOffset();
 
         bool visible = false;
         // Check if the current point needs to be displayed.
-        if (drawOffset > -markHalfWidth &&
-                drawOffset < m_waveformRenderer->getLength() +
-                                markHalfWidth) {
+        if (drawOffset > -markWidth &&
+                drawOffset < m_waveformRenderer->getLength()) {
             drawTexture(matrix,
                     drawOffset,
                     !m_isSlipRenderer && slipActive
@@ -299,10 +298,8 @@ void allshader::WaveformRenderMark::paintGL() {
             devicePixelRatio;
 
     if (m_playPosMarkTexture.isStorageAllocated()) {
-        const float markHalfWidth = m_playPosMarkTexture.width() / devicePixelRatio / 2.f;
-        const float drawOffset = currentMarkPoint - markHalfWidth;
-
-        drawTexture(matrix, drawOffset, 0.f, &m_playPosMarkTexture);
+        const float drawOffset = -(m_playPosMarkTexture.width() / devicePixelRatio - 1.f) / 2.f;
+        drawTexture(matrix, currentMarkPoint + drawOffset, 0.f, &m_playPosMarkTexture);
     }
 
     if (WaveformWidgetFactory::instance()->getUntilMarkShowBeats() ||
@@ -404,8 +401,8 @@ void allshader::WaveformRenderMark::updatePlayPosMarkTexture() {
     // lines next to playpos
     // Note: don't draw lines where they would overlap the triangles,
     // otherwise both translucent strokes add up to a darker tone.
-    painter.drawLine(QLineF(lineX + 1.f, 4.f, lineX + 1.f, height));
-    painter.drawLine(QLineF(lineX - 1.f, 4.f, lineX - 1.f, height));
+    painter.drawLine(QLineF(lineX + 1.f, 4.f, lineX + 1.f, height / 3));
+    painter.drawLine(QLineF(lineX - 1.f, 4.f, lineX - 1.f, height / 3));
 
     // triangle at top edge
     // Increase line/waveform contrast
@@ -420,7 +417,7 @@ void allshader::WaveformRenderMark::updatePlayPosMarkTexture() {
     painter.setPen(fgColor);
     painter.setOpacity(1.0);
     // play position line
-    painter.drawLine(QLineF(lineX, 0.f, lineX, height));
+    painter.drawLine(QLineF(lineX, 0.f, lineX, height / 3));
     // triangle at top edge
     {
         QPointF baseL = QPointF(lineX - 4.f, 0.f);

src/waveform/renderers/waveformmark.cpp

@@ -100,6 +100,7 @@ WaveformMark::WaveformMark(const QString& group,
         const WaveformSignalColors& signalColors,
         int hotCue)
         : m_linePosition{},
+          m_offset{},
           m_breadth{},
           m_level{},
           m_iPriority(priority),
@@ -278,6 +279,8 @@ struct MarkerGeometry {
         const Qt::Alignment alignH = align & Qt::AlignHorizontal_Mask;
         const Qt::Alignment alignV = align & Qt::AlignVertical_Mask;
         const bool alignHCenter{alignH == Qt::AlignHCenter};
+        // when center aligning, make the image width odd (even label width + 1)
+        // so we can draw the line at a integer pixel position
         const qreal widthRounding{alignHCenter ? 2.f : 1.f};
 
         m_labelRect = QRectF{0.f,
@@ -286,17 +289,9 @@ struct MarkerGeometry {
                         widthRounding,
                 std::ceil(capHeight + 2.f * margin)};
 
-        m_imageSize = QSizeF{alignHCenter ? m_labelRect.width() + 1.f
-                                          : 2.f * m_labelRect.width() + 1.f,
-                breadth};
+        m_imageSize = QSizeF{m_labelRect.width() + 1.f, breadth};
 
-        if (alignH == Qt::AlignHCenter) {
-            m_labelRect.moveLeft((m_imageSize.width() - m_labelRect.width()) / 2.f);
-        } else if (alignH == Qt::AlignRight) {
-            m_labelRect.moveRight(m_imageSize.width() - 0.5f);
-        } else {
-            m_labelRect.moveLeft(0.5f);
-        }
+        m_labelRect.moveLeft(0.5f);
 
         const float increment = overlappingMarkerIncrement(
                 static_cast<float>(m_labelRect.height()), breadth);
@@ -373,23 +368,39 @@ QImage WaveformMark::generateImage(float devicePixelRatio) {
 
     painter.setWorldMatrixEnabled(false);
 
-    // Draw marker lines
-    const auto hcenter = markerGeometry.m_imageSize.width() / 2.f;
-    m_linePosition = static_cast<float>(hcenter);
+    const Qt::Alignment alignH = m_align & Qt::AlignHorizontal_Mask;
+    switch (alignH) {
+    case Qt::AlignHCenter:
+        m_linePosition = markerGeometry.m_imageSize.width() / 2.f;
+        m_offset = -(markerGeometry.m_imageSize.width() - 1.f) / 2.f;
+        DEBUG_ASSERT(linePos - std::roundf(linePos) < 0.000001f);
+        break;
+    case Qt::AlignLeft:
+        m_linePosition = markerGeometry.m_imageSize.width() - 1.5f;
+        m_offset = -markerGeometry.m_imageSize.width() + 2.f;
+        break;
+    case Qt::AlignRight:
+    default:
+        m_linePosition = 1.5f;
+        m_offset = -1.f;
+        break;
+    }
+
+    const float linePos = m_linePosition;
 
     // Draw the center line
     painter.setPen(fillColor());
-    painter.drawLine(QLineF(hcenter, 0.f, hcenter, markerGeometry.m_imageSize.height()));
+    painter.drawLine(QLineF(linePos, 0.f, linePos, markerGeometry.m_imageSize.height() / 2));
 
     painter.setPen(borderColor());
-    painter.drawLine(QLineF(hcenter - 1.f,
+    painter.drawLine(QLineF(linePos - 1.f,
             0.f,
-            hcenter - 1.f,
-            markerGeometry.m_imageSize.height()));
-    painter.drawLine(QLineF(hcenter + 1.f,
+            linePos - 1.f,
+            markerGeometry.m_imageSize.height() / 2));
+    painter.drawLine(QLineF(linePos + 1.f,
             0.f,
-            hcenter + 1.f,
-            markerGeometry.m_imageSize.height()));
+            linePos + 1.f,
+            markerGeometry.m_imageSize.height() / 2));
 
     if (useIcon || label.length() != 0) {
         painter.setPen(borderColor());

src/waveform/renderers/waveformmark.h

@@ -37,6 +37,10 @@ class WaveformMark {
     WaveformMark(const WaveformMark&) = delete;
     WaveformMark& operator=(const WaveformMark&) = delete;
 
+    float getOffset() const {
+        return m_offset;
+    }
+
     int getHotCue() const {
         return m_iHotCue;
     };
@@ -158,6 +162,7 @@ class WaveformMark {
     QString m_iconPath;
 
     float m_linePosition;
+    float m_offset;
     float m_breadth;
 
     // When there are overlapping marks, level is increased for each overlapping mark,