Replace Dropzone VTKActor by IMGUI #1990

Ni-g-3l · 2025-02-15T18:19:45Z

Hello !

I try to replace DropZone Actor by a IMGUI window. I'm not ImGUI expert if you see a better way to do it do not hesitate to comment.

Linked issue : #1975

mwestphal · 2025-02-15T18:20:53Z

Do you think you could put an outline around the text, like its done for the filename ?

mwestphal · 2025-02-15T18:23:07Z

Other than that, its looking good! Dont hesitate to share such screenshot on discord :)

mwestphal · 2025-02-15T18:23:49Z

However, how can I update tests in order to match the new dropzone ?

You just need to update the baselines

Ni-g-3l · 2025-02-15T18:24:44Z

Sorry I don't understand ? Where I can find the example to put outline on text ? because my update on DropText look very similar at what it is done for FileName

mwestphal · 2025-02-15T19:12:27Z

I think its handled by SetupNextWindow

mwestphal · 2025-02-15T19:13:11Z

I mean this:

snoyer · 2025-02-16T05:51:36Z

@Ni-g-3l I would suggest trying absurdly high values for tickThickness and tickLength in order to highlight accuracy/precision issues in the drawing logic.

For example, using:

    constexpr float tickThickness = 25.0f;
    constexpr float tickLength = 40.0f;

this PR's ImGui code shows:

while the previous VTK code shows:

The key point here is that the previous code was drawing rectangles and the new code is drawing thick lines so there's going to be some ±thickness/2 offsets to account for somewhere somehow

(also check to make sure it all still works when resizing the window)

possible fix/improvement

diff --git a/vtkext/private/module/vtkF3DImguiActor.cxx b/vtkext/private/module/vtkF3DImguiActor.cxx
index b54e941c..c386d537 100644
--- a/vtkext/private/module/vtkF3DImguiActor.cxx
+++ b/vtkext/private/module/vtkF3DImguiActor.cxx
@@ -299,8 +299,8 @@ void vtkF3DImguiActor::RenderDropZone()
     constexpr float tickLength = 10.0f;
 
     int dropzonePad = static_cast<int>(std::min(viewport->WorkSize.x, viewport->WorkSize.y) * 0.1);
-    int dropZoneW = viewport->WorkSize.x - dropzonePad;
-    int dropZoneH = viewport->WorkSize.y - dropzonePad;
+    int dropZoneW = viewport->WorkSize.x - dropzonePad * 2;
+    int dropZoneH = viewport->WorkSize.y - dropzonePad * 2;
 
     ::SetupNextWindow(ImVec2(0, 0), viewport->WorkSize);
     ImGui::SetNextWindowBgAlpha(0.f);
@@ -312,7 +312,7 @@ void vtkF3DImguiActor::RenderDropZone()
     ImDrawList* draw_list = ImGui::GetWindowDrawList();
 
     ImVec2 p0(dropzonePad, dropzonePad);
-    ImVec2 p1(dropZoneW, dropZoneH);
+    ImVec2 p1(dropzonePad + dropZoneW, dropzonePad + dropZoneH);
     int tickNumberW = static_cast<int>(std::ceil(dropZoneW / (tickLength * 2.0f)));
     int tickNumberH = static_cast<int>(std::ceil(dropZoneH / (tickLength * 2.0f)));
     double tickSpaceW =
@@ -323,22 +323,24 @@ void vtkF3DImguiActor::RenderDropZone()
     // Draw top and bottom line
     for (float x = p0.x; x < p1.x; x += tickLength + tickSpaceW)
     {
-      draw_list->AddLine(ImVec2(x, p0.y), ImVec2(x + tickLength, p0.y), color, tickThickness);
-      draw_list->AddLine(ImVec2(x, p1.y), ImVec2(x + tickLength, p1.y), color, tickThickness);
+      const float y0 = p0.y + tickThickness / 2.f;
+      const float y1 = p1.y - tickThickness / 2.f;
+      draw_list->AddLine(ImVec2(x, y0), ImVec2(x + tickLength, y0), color, tickThickness);
+      draw_list->AddLine(ImVec2(x, y1), ImVec2(x + tickLength, y1), color, tickThickness);
     }
 
     // Draw left and right line
     for (float y = p0.y; y < p1.y; y += tickLength + tickSpaceH)
     {
-      draw_list->AddLine(ImVec2(p0.x, y), ImVec2(p0.x, y + tickLength), color, tickThickness);
-      draw_list->AddLine(ImVec2(p1.x, y), ImVec2(p1.x, y + tickLength), color, tickThickness);
+      const float x0 = p0.x + tickThickness / 2.f;
+      const float x1 = p1.x - tickThickness / 2.f;
+      draw_list->AddLine(ImVec2(x0, y), ImVec2(x0, y + tickLength), color, tickThickness);
+      draw_list->AddLine(ImVec2(x1, y), ImVec2(x1, y + tickLength), color, tickThickness);
     }
 
     ImGui::End();
 
     ImVec2 dropTextSize = ImGui::CalcTextSize(this->DropText.c_str());
-    dropTextSize.x += 2.f * ImGui::GetStyle().WindowPadding.x;
-    dropTextSize.y += 2.f * ImGui::GetStyle().WindowPadding.y;
 
     ImGui::Begin("DropZoneText", nullptr, flags);
     ImGui::SetCursorPos(ImVec2(viewport->GetWorkCenter().x - 0.5f * dropTextSize.x,

Ni-g-3l · 2025-02-16T17:46:27Z

I try to fix what you find, with my latest commit

I will fix the CICD tomorow

snoyer

@Ni-g-3l I believe you forgot to double the padding at the beginning and ended up trying to compensate for that all along later

vtkext/private/module/vtkF3DImguiActor.cxx

snoyer · 2025-02-17T05:41:02Z

vtkext/private/module/vtkF3DImguiActor.cxx

+    double tickBBSizeW = tickLength + tickSpaceW;
+    double tickBBSizeH = tickLength + tickSpaceH;
+
+    // Draw top and bottom line
+    for (float x = p0.x - tickHalfThickness; x < p1.x - tickBBSizeW; x += tickBBSizeW)
+    {
+      draw_list->AddLine(ImVec2(x, p0.y), ImVec2(x + tickLength, p0.y), color, tickThickness);
+      draw_list->AddLine(ImVec2(x, p1.y), ImVec2(x + tickLength, p1.y), color, tickThickness);
+    }
+
+    draw_list->AddLine(ImVec2(p1.x - tickLength, p0.y), ImVec2(p1.x + tickHalfThickness, p0.y),
+      color, tickThickness);
+    draw_list->AddLine(ImVec2(p1.x - tickLength, p1.y), ImVec2(p1.x + tickHalfThickness, p1.y),
+      color, tickThickness);
+
+    // Draw left and right line
+    for (float y = p0.y - tickHalfThickness; y < p1.y - tickBBSizeH; y += tickBBSizeH)
+    {
+      draw_list->AddLine(ImVec2(p0.x, y), ImVec2(p0.x, y + tickLength), color, tickThickness);
+      draw_list->AddLine(ImVec2(p1.x, y), ImVec2(p1.x, y + tickLength), color, tickThickness);
+    }
+
+    draw_list->AddLine(ImVec2(p0.x, p1.y - tickLength), ImVec2(p0.x, p1.y + tickHalfThickness),
+      color, tickThickness);
+    draw_list->AddLine(ImVec2(p1.x, p1.y - tickLength), ImVec2(p1.x, p1.y + tickHalfThickness),
+      color, tickThickness);


the half-thickness offset you want is only to draw the lines inside the target rectangle rather that on it:

vs

So you just have to to shift the top/bottom lines down/up and the right/left lines left/right, no need to modify/extend the loops:

Suggested change

double tickBBSizeW = tickLength + tickSpaceW;

double tickBBSizeH = tickLength + tickSpaceH;

// Draw top and bottom line

for (float x = p0.x - tickHalfThickness; x < p1.x - tickBBSizeW; x += tickBBSizeW)

{

draw_list->AddLine(ImVec2(x, p0.y), ImVec2(x + tickLength, p0.y), color, tickThickness);

draw_list->AddLine(ImVec2(x, p1.y), ImVec2(x + tickLength, p1.y), color, tickThickness);

}

draw_list->AddLine(ImVec2(p1.x - tickLength, p0.y), ImVec2(p1.x + tickHalfThickness, p0.y),

color, tickThickness);

draw_list->AddLine(ImVec2(p1.x - tickLength, p1.y), ImVec2(p1.x + tickHalfThickness, p1.y),

color, tickThickness);

// Draw left and right line

for (float y = p0.y - tickHalfThickness; y < p1.y - tickBBSizeH; y += tickBBSizeH)

{

draw_list->AddLine(ImVec2(p0.x, y), ImVec2(p0.x, y + tickLength), color, tickThickness);

draw_list->AddLine(ImVec2(p1.x, y), ImVec2(p1.x, y + tickLength), color, tickThickness);

}

draw_list->AddLine(ImVec2(p0.x, p1.y - tickLength), ImVec2(p0.x, p1.y + tickHalfThickness),

color, tickThickness);

draw_list->AddLine(ImVec2(p1.x, p1.y - tickLength), ImVec2(p1.x, p1.y + tickHalfThickness),

color, tickThickness);

// Draw top and bottom line

for (float x = p0.x; x < p1.x; x += tickLength + tickSpaceW)

{

const float y0 = p0.y + tickThickness / 2.f;

const float y1 = p1.y - tickThickness / 2.f;

draw_list->AddLine(ImVec2(x, y0), ImVec2(x + tickLength, y0), color, tickThickness);

draw_list->AddLine(ImVec2(x, y1), ImVec2(x + tickLength, y1), color, tickThickness);

}

// Draw left and right line

for (float y = p0.y; y < p1.y; y += tickLength + tickSpaceH)

{

const float x0 = p0.x + tickThickness / 2.f;

const float x1 = p1.x - tickThickness / 2.f;

draw_list->AddLine(ImVec2(x0, y), ImVec2(x0, y + tickLength), color, tickThickness);

draw_list->AddLine(ImVec2(x1, y), ImVec2(x1, y + tickLength), color, tickThickness);

}

vtkext/private/module/vtkF3DImguiActor.cxx

mwestphal · 2025-03-01T11:33:05Z

Hi @Ni-g-3l

Do you need help or review into order to move forward ?

Co-authored-by: snoyer <noyer.stephane@gmail.com>

Ni-g-3l · 2025-03-03T19:37:16Z

Hello ! Sorry I was quite busy last week ! I will try to take a look this week in order to provide healthy base for the future implementation of the new drop zone

Ni-g-3l · 2025-03-05T08:45:08Z

So I try all of your propositions @snoyer, but it wasn't worked as expected. If we want to ensure the dropZone rectangle is always correctly closed we have to draw the the last tick independantly from the loop.

The current implementation is looking like this :

The only problem that I can see is the different space length between the last tick of each line and the previous one.

Feel free to review and comment if you think I should try another implementation !

snoyer · 2025-03-05T09:51:03Z

@Ni-g-3l I think you should refer to the original computations for the dashing (you may want to keep the comments too)

f3d/vtkext/private/module/vtkF3DDropZoneActor.cxx

Lines 66 to 77 in c7f7a99

    
           // padding is 10% of shortest side 
        
           int padding = static_cast<int>(std::min(vSize[0], vSize[1]) * 0.1); 
        
           int borderW = vSize[0] - 2 * padding; 
        
           int borderH = vSize[1] - 2 * padding; 
        
           // number of ticks assuming spacing == tickLength 
        
           int nTicksW = static_cast<int>(std::ceil(borderW / (tickLength * 2.0))); 
        
           int nTicksH = static_cast<int>(std::ceil(borderH / (tickLength * 2.0))); 
        
           // recompute uniform spacing 
        
           double spacingW = static_cast<double>(borderW - nTicksW * tickLength) / (nTicksW - 1); 
        
           double spacingH = static_cast<double>(borderH - nTicksH * tickLength) / (nTicksH - 1);

I believe your original version was only missing the offsetting to draw inside of the target rectangle instead of exactly on it (see this 2 images #1990 (comment)).

Here's a snippet that seem to work for me:

    const double tickSpaceW =
      static_cast<double>(dropZoneW - tickNumberW * tickLength) / (tickNumberW - 1);
    const double tickSpaceH =
      static_cast<double>(dropZoneH - tickNumberH * tickLength) / (tickNumberH - 1);

    ::SetupNextWindow(ImVec2(0, 0), viewport->WorkSize);
    ImGui::SetNextWindowBgAlpha(0.f);

    ImGuiWindowFlags flags = ImGuiWindowFlags_NoDecoration | ImGuiWindowFlags_NoSavedSettings |
      ImGuiWindowFlags_NoFocusOnAppearing | ImGuiWindowFlags_NoNav | ImGuiWindowFlags_NoMove;

    ImGui::Begin("DropZoneText", nullptr, flags);
    ImDrawList* draw_list = ImGui::GetWindowDrawList();

    const ImVec2 p0(dropzonePad, dropzonePad);
    const ImVec2 p1(dropzonePad + dropZoneW, dropzonePad + dropZoneH);

    // Draw top and bottom line
    for (float x = p0.x; x < p1.x; x += tickLength + tickSpaceW)
    {
      const float y0 = p0.y + tickThickness / 2.f;
      const float y1 = p1.y - tickThickness / 2.f;
      draw_list->AddLine(ImVec2(x, y0), ImVec2(x + tickLength, y0), color, tickThickness);
      draw_list->AddLine(ImVec2(x, y1), ImVec2(x + tickLength, y1), color, tickThickness);
    }
    // Draw left and right line
    for (float y = p0.y; y < p1.y; y += tickLength + tickSpaceH)
    {
      const float x0 = p0.x + tickThickness / 2.f;
      const float x1 = p1.x - tickThickness / 2.f;
      draw_list->AddLine(ImVec2(x0, y), ImVec2(x0, y + tickLength), color, tickThickness);
      draw_list->AddLine(ImVec2(x1, y), ImVec2(x1, y + tickLength), color, tickThickness);
    }

    {
      /* target rectangle for debugging ;) */
      constexpr ImU32 red = IM_COL32(255, 0, 0, 255);
      draw_list->AddLine(ImVec2(p0.x, p0.x), ImVec2(p1.x, p0.y), red, 1);
      draw_list->AddLine(ImVec2(p0.x, p1.y), ImVec2(p1.x, p1.y), red, 1);
      draw_list->AddLine(ImVec2(p0.x, p0.x), ImVec2(p0.x, p1.y), red, 1);
      draw_list->AddLine(ImVec2(p1.x, p0.x), ImVec2(p1.x, p1.y), red, 1);
    }

Ni-g-3l mentioned this pull request Feb 15, 2025

Convert dropzone widget into ImGui widget #1975

Open

snoyer reviewed Feb 17, 2025

View reviewed changes

mwestphal linked an issue Mar 1, 2025 that may be closed by this pull request

Convert dropzone widget into ImGui widget #1975

Open

Ni-g-3l and others added 6 commits March 3, 2025 20:34

application: Replace VTK DropZone Actor and replace it by ImGUI Widget

34c04bb

chore: Format code

d4ac9bb

application: Ensure DropZone dashed are correctly aligned

10467bc

application: store tickHalfThickNess is const

539c04e

application: Fix DropZone windows padding

1546cfc

Co-authored-by: snoyer <noyer.stephane@gmail.com>

application: Remove useless padding on dropText

4d7bde7

Co-authored-by: snoyer <noyer.stephane@gmail.com>

application: Force draw last dropZone tick to ensure dropZone close

4268995

Ni-g-3l force-pushed the remove-dropzone-vtk-actor branch from c68a5cb to 4268995 Compare March 5, 2025 08:38

applications: Remove dropzone loop extension for last tick draw

3bb11af

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Replace Dropzone VTKActor by IMGUI #1990

Replace Dropzone VTKActor by IMGUI #1990

Ni-g-3l commented Feb 15, 2025 •

edited

Loading

mwestphal commented Feb 15, 2025

mwestphal commented Feb 15, 2025

mwestphal commented Feb 15, 2025

Ni-g-3l commented Feb 15, 2025

mwestphal commented Feb 15, 2025

mwestphal commented Feb 15, 2025 •

edited

Loading

snoyer commented Feb 16, 2025 •

edited

Loading

Ni-g-3l commented Feb 16, 2025

snoyer left a comment

snoyer Feb 17, 2025

mwestphal commented Mar 1, 2025

Ni-g-3l commented Mar 3, 2025

Ni-g-3l commented Mar 5, 2025

snoyer commented Mar 5, 2025

Replace Dropzone VTKActor by IMGUI #1990

Are you sure you want to change the base?

Replace Dropzone VTKActor by IMGUI #1990

Conversation

Ni-g-3l commented Feb 15, 2025 • edited Loading

mwestphal commented Feb 15, 2025

mwestphal commented Feb 15, 2025

mwestphal commented Feb 15, 2025

Ni-g-3l commented Feb 15, 2025

mwestphal commented Feb 15, 2025

mwestphal commented Feb 15, 2025 • edited Loading

snoyer commented Feb 16, 2025 • edited Loading

Ni-g-3l commented Feb 16, 2025

snoyer left a comment

Choose a reason for hiding this comment

snoyer Feb 17, 2025

Choose a reason for hiding this comment

mwestphal commented Mar 1, 2025

Ni-g-3l commented Mar 3, 2025

Ni-g-3l commented Mar 5, 2025

snoyer commented Mar 5, 2025

Ni-g-3l commented Feb 15, 2025 •

edited

Loading

mwestphal commented Feb 15, 2025 •

edited

Loading

snoyer commented Feb 16, 2025 •

edited

Loading