mirror of
https://github.com/OrcaSlicer/OrcaSlicer.git
synced 2026-09-22 16:32:40 +00:00
Hanif Koh
1acec9f88f
The G-code preview draws every toolpath segment as an instanced box, and its frame cost is linear in the number of segments drawn. On a plate of large objects that is enough that dragging the camera or a preview slider cannot keep up, and no amount of per-segment work changes that; only drawing fewer segments does. The objects themselves are cheaper: a mesh costs its triangles once, however many layers it has, and the preview already loads the objects as shells for its translucent ghost. A new preference, "Only render solid model when dragging" (off by default), draws those shells opaque in their filament colours instead of the toolpaths while the user drags. The visible layer range still holds. The shells are cut at the range's top and bottom through the gouraud shader's z range, and libvgcode keeps a second index buffer holding just the range's bottom and top layers, filled in the same walk as the full one, which is drawn afterwards so that it caps the cut with what was really printed there. Switching between the two sets is a buffer binding, never a rebuild. The prime tower is added to the shells from its sliced mesh while the preference is on, positioned as the print placed it; it keeps its opaque colour and so stays out of the translucent ghost. Supports have no mesh and are not shown. Dragging is the camera, the navigator or either slider being held; a slider reports it from ImGui's active id, since its dirty flag is raised and consumed inside one frame. A wheel step holds the solid model for a 150 ms settle time, with the frame that restores the toolpaths scheduled for when it runs out. The switch is decided at the top of the frame, before the cached scene is consulted, and a frame that switches redraws the scene. A drag cut short by focus or capture loss is ended explicitly, and a button release wakes the idle loop, since on some platforms no idle event follows it until the next input. With the preference off, nothing is built and the preview is unchanged.