Add scene viewport move gizmo workflow

editor/src/Viewport/SceneViewportOverlayRenderer.cpp

@@ -10,6 +10,18 @@ Math::Matrix4x4 BuildOverlayViewMatrix(const SceneViewportOverlayData& overlay)
     return BuildSceneViewportViewMatrix(overlay);
 }
 
+ImU32 ToImGuiColor(const Math::Color& color) {
+    const auto toChannel = [](float value) -> int {
+        return static_cast<int>(std::clamp(value, 0.0f, 1.0f) * 255.0f + 0.5f);
+    };
+
+    return IM_COL32(
+        toChannel(color.r),
+        toChannel(color.g),
+        toChannel(color.b),
+        toChannel(color.a));
+}
+
 void DrawAxisLabel(ImDrawList* drawList, const ImVec2& position, const char* label, ImU32 color) {
     if (drawList == nullptr || label == nullptr) {
         return;
@@ -61,6 +73,31 @@ void DrawSceneAxisWidget(
     }
 }
 
+void DrawSceneMoveGizmo(
+    ImDrawList* drawList,
+    const SceneViewportMoveGizmoDrawData& moveGizmo) {
+    if (drawList == nullptr || !moveGizmo.visible) {
+        return;
+    }
+
+    const ImVec2 pivot(moveGizmo.pivot.x, moveGizmo.pivot.y);
+    drawList->AddCircleFilled(pivot, moveGizmo.pivotRadius + 1.0f, IM_COL32(20, 22, 24, 220), 20);
+    drawList->AddCircle(pivot, moveGizmo.pivotRadius + 1.0f, IM_COL32(255, 255, 255, 48), 20, 1.0f);
+
+    for (const SceneViewportMoveGizmoHandleDrawData& handle : moveGizmo.handles) {
+        if (!handle.visible) {
+            continue;
+        }
+
+        const ImU32 color = ToImGuiColor(handle.color);
+        const float thickness = handle.active ? 4.0f : (handle.hovered ? 3.0f : 2.0f);
+        const ImVec2 start(handle.start.x, handle.start.y);
+        const ImVec2 end(handle.end.x, handle.end.y);
+        drawList->AddLine(start, end, color, thickness);
+        drawList->AddCircleFilled(end, handle.active ? 6.5f : 5.5f, color, 20);
+    }
+}
+
 } // namespace
 
 void DrawSceneViewportOverlay(
@@ -68,13 +105,19 @@ void DrawSceneViewportOverlay(
     const SceneViewportOverlayData& overlay,
     const ImVec2& viewportMin,
     const ImVec2& viewportMax,
-    const ImVec2& viewportSize) {
-    if (drawList == nullptr || !overlay.valid || viewportSize.x <= 1.0f || viewportSize.y <= 1.0f) {
+    const ImVec2& viewportSize,
+    const SceneViewportMoveGizmoDrawData* moveGizmo) {
+    if (drawList == nullptr || viewportSize.x <= 1.0f || viewportSize.y <= 1.0f) {
         return;
     }
 
     drawList->PushClipRect(viewportMin, viewportMax, true);
-    DrawSceneAxisWidget(drawList, overlay, viewportMin, viewportMax);
+    if (overlay.valid) {
+        DrawSceneAxisWidget(drawList, overlay, viewportMin, viewportMax);
+    }
+    if (moveGizmo != nullptr) {
+        DrawSceneMoveGizmo(drawList, *moveGizmo);
+    }
     drawList->PopClipRect();
 }