Timeline: Make 0-width events visible again.

Events with duration == 0 were erroneously filtered out by the items
render pass. Also, we have to give them a very small width in order for
the "stretching" mechanism in the vertex shader to work.

Change-Id: Icb76168f0831547a3ca55ab79df7161736ed4dc4
Task-number: QTCREATORBUG-14446
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

3 files changed, 18 insertions, 12 deletions

diff --git a/src/libs/timeline/qml/timelineitems.vert b/src/libs/timeline/qml/timelineitems.vert
index cea5b49cd4..f8cfb40adb 100644
--- a/src/libs/timeline/qml/timelineitems.vert
+++ b/src/libs/timeline/qml/timelineitems.vert
@@ -48,7 +48,7 @@ void main()
 
     // Make very narrow events somewhat wider so that they don't collapse into 0 pixels
     float scaledWidth = scale.x * rectSize.x;
-    float shift = sign(scaledWidth) * max(0.0, 3.0 - abs(scaledWidth)) * 0.0005;
+    float shift = sign(rectSize.x) * max(0.0, 3.0 - abs(scaledWidth)) * 0.0005;
     gl_Position.x += shift;
 
     // Ditto for events with very small height
diff --git a/src/libs/timeline/timelineitemsrenderpass.cpp b/src/libs/timeline/timelineitemsrenderpass.cpp
index 41f0a362cd..114cd5983a 100644
--- a/src/libs/timeline/timelineitemsrenderpass.cpp
+++ b/src/libs/timeline/timelineitemsrenderpass.cpp
@@ -202,7 +202,7 @@ static void updateNodes(int from, int to, const TimelineModel *model,
     for (int i = from; i < to; ++i) {
         qint64 start = qMax(parentState->start(), model->startTime(i));
         qint64 end = qMin(parentState->end(), model->startTime(i) + model->duration(i));
-        if (start >= end)
+        if (start > end)
             continue;
 
         float itemTop = (1.0 - model->relativeHeight(i)) * defaultRowHeight;
@@ -230,7 +230,7 @@ static void updateNodes(int from, int to, const TimelineModel *model,
     for (int i = from; i < to; ++i) {
         qint64 start = qMax(parentState->start(), model->startTime(i));
         qint64 end = qMin(parentState->end(), model->startTime(i) + model->duration(i));
-        if (start >= end)
+        if (start > end)
             continue;
 
         QColor color = model->color(i);
@@ -238,7 +238,8 @@ static void updateNodes(int from, int to, const TimelineModel *model,
         uchar green = color.green();
         uchar blue = color.blue();
 
-        float itemWidth = (end - start) * parentState->scale();
+        float itemWidth = end > start ? (end - start) * parentState->scale() :
+                                        std::numeric_limits<float>::min();
         float itemLeft = (start - parentState->start()) * parentState->scale();
 
         // This has to be the exact same expression as above, to guarantee determinism.
diff --git a/tests/auto/timeline/timelineitemsrenderpass/tst_timelineitemsrenderpass.cpp b/tests/auto/timeline/timelineitemsrenderpass/tst_timelineitemsrenderpass.cpp
index c2cff9cffb..b7944890af 100644
--- a/tests/auto/timeline/timelineitemsrenderpass/tst_timelineitemsrenderpass.cpp
+++ b/tests/auto/timeline/timelineitemsrenderpass/tst_timelineitemsrenderpass.cpp
@@ -105,6 +105,8 @@ void DummyModel::loadData()
 {
     for (int i = 0; i < 10; ++i)
         insert(i, 1, 1);
+
+    insert(5, 0, 10);
 }
 
 float DummyModel::relativeHeight(int index) const
@@ -139,7 +141,7 @@ void tst_TimelineItemsRenderPass::update()
     result = inst->update(&renderer, &parentState, 0, 0, 0, true, 1);
     QCOMPARE(result, nullState);
 
-    result = inst->update(&renderer, &parentState, 0, 2, 8, true, 1);
+    result = inst->update(&renderer, &parentState, 0, 2, 9, true, 1);
     QVERIFY(result != nullState);
     QCOMPARE(result->expandedOverlay(), nullNode);
     QCOMPARE(result->expandedOverlay(), nullNode);
@@ -150,10 +152,10 @@ void tst_TimelineItemsRenderPass::update()
     QSGGeometryNode *node = static_cast<QSGGeometryNode *>(result->expandedRows()[0]->firstChild());
     QSGMaterial *material1 = node->material();
     QVERIFY(material1 != 0);
-    QCOMPARE(node->geometry()->vertexCount(), 26);
+    QCOMPARE(node->geometry()->vertexCount(), 30);
     node = static_cast<QSGGeometryNode *>(result->collapsedRows()[0]->firstChild());
     QSGMaterial *material2 = node->material();
-    QCOMPARE(node->geometry()->vertexCount(), 26);
+    QCOMPARE(node->geometry()->vertexCount(), 30);
     QVERIFY(material2 != 0);
     QCOMPARE(material1->type(), material2->type());
     QSGMaterialShader *shader1 = material1->createShader();
@@ -165,17 +167,20 @@ void tst_TimelineItemsRenderPass::update()
     delete shader1;
     delete shader2;
 
-    result = inst->update(&renderer, &parentState, result, 0, 10, true, 1);
+    result = inst->update(&renderer, &parentState, result, 0, 11, true, 1);
     QVERIFY(result != nullState);
     QCOMPARE(result->expandedOverlay(), nullNode);
     QCOMPARE(result->expandedOverlay(), nullNode);
     QCOMPARE(result->expandedRows().count(), 1);
     QCOMPARE(result->collapsedRows().count(), 1);
-    QCOMPARE(result->expandedRows()[0]->childCount(), 2);
-    QCOMPARE(result->collapsedRows()[0]->childCount(), 2);
-    node = static_cast<QSGGeometryNode *>(result->expandedRows()[0]->lastChild());
+
+    // 0-sized node starting at 8 may also be added. We don't test for this one.
+    QVERIFY(result->expandedRows()[0]->childCount() > 1);
+    QVERIFY(result->collapsedRows()[0]->childCount() > 1);
+
+    node = static_cast<QSGGeometryNode *>(result->expandedRows()[0]->childAtIndex(1));
     QCOMPARE(node->geometry()->vertexCount(), 8);
-    node = static_cast<QSGGeometryNode *>(result->collapsedRows()[0]->lastChild());
+    node = static_cast<QSGGeometryNode *>(result->collapsedRows()[0]->childAtIndex(1));
     QCOMPARE(node->geometry()->vertexCount(), 8);
 
     model.setExpanded(true);