From 7804c6a96d26c2e757d09f1864eb73fb81eb280f Mon Sep 17 00:00:00 2001
From: Fox Caminiti <fox@foxcam.net>
Date: Thu, 20 Oct 2022 20:45:37 -0400
Subject: precomp recursion!

---
 imgui_helper_widgets.cpp | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 imgui_helper_widgets.cpp

(limited to 'imgui_helper_widgets.cpp')

diff --git a/imgui_helper_widgets.cpp b/imgui_helper_widgets.cpp
new file mode 100644
index 0000000..105dad2
--- /dev/null
+++ b/imgui_helper_widgets.cpp
@@ -0,0 +1,68 @@
+// Widgets not directly related to drawing UI.
+
+// Returns a normalized UV position of the composition
+static v2
+ImGui_ScreenPointToCompUV(ImVec2 ViewportMin, ImVec2 CompPos, ImVec2 CompZoom, ImVec2 MousePos)
+{
+    ImVec2 LocalMousePos = MousePos - ViewportMin;
+    ImVec2 LocalCompPos = CompPos - ViewportMin;
+    ImVec2 MouseScreenUV = LocalMousePos - LocalCompPos;
+    ImVec2 Result = MouseScreenUV / CompZoom;
+    return V2(Result);
+}
+
+// NOTE(fox): We have to do a bit of hackery here to tell how many times the
+// mouse has been warped during a drag, since it doesn't seem like we can rely
+// on SDL_WarpMouseGlobal to update on the first frame of a WantSetPos request.
+
+static void
+ImGui_WarpMouse(ui *UI, ImVec2 MousePos, ImVec2 Min, ImVec2 Max, int Direction = 3)
+{
+    if (Direction & 1) {
+        if (MousePos.x < Min.x) {
+            UI->Warp_WantSetPos = true;
+            UI->Warp_PositionToSet = ImVec2(Max.x - 5, MousePos.y);
+            UI->Warp_PositionInitial = MousePos.x;
+            UI->Warp_Direction = 0;
+        }
+        if (MousePos.x > Max.x) {
+            UI->Warp_WantSetPos = true;
+            UI->Warp_PositionToSet = ImVec2(Min.x + 5, MousePos.y);
+            UI->Warp_PositionInitial = MousePos.x;
+            UI->Warp_Direction = 1;
+        }
+    }
+    if (Direction & 2) {
+        if (MousePos.y < Min.y) {
+            UI->Warp_WantSetPos = true;
+            UI->Warp_PositionToSet = ImVec2(MousePos.x, Max.y - 5);
+            UI->Warp_PositionInitial = MousePos.y;
+            UI->Warp_Direction = 2;
+        }
+        if (MousePos.y > Max.y) {
+            UI->Warp_WantSetPos = true;
+            UI->Warp_PositionToSet = ImVec2(MousePos.x, Min.y + 5);
+            UI->Warp_PositionInitial = MousePos.y;
+            UI->Warp_Direction = 3;
+        }
+    }
+}
+
+// We record the initial position and the direction of the wrap, and only
+// increment the wrap amount when MousePos actually is measured to be what we expect.
+
+static void
+ImGui_WarpMouseFinish(ui *UI, ImVec2 MousePos)
+{
+    if (UI->Warp_Direction == 0) {
+        if (MousePos.x < UI->Warp_PositionInitial) UI->Warp_X--;
+    } else if (UI->Warp_Direction == 1) {
+        if (MousePos.x > UI->Warp_PositionInitial) UI->Warp_X++;
+    } else if (UI->Warp_Direction == 2) {
+        if (MousePos.y < UI->Warp_PositionInitial) UI->Warp_Y--;
+    } else if (UI->Warp_Direction == 3) {
+        if (MousePos.y > UI->Warp_PositionInitial) UI->Warp_Y++;
+    } else {
+        Assert(0);
+    }
+}
-- 
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