1 files changed, 90 insertions, 0 deletions
diff --git a/src/imgui_helper.cpp b/src/imgui_helper.cpp
new file mode 100644
index 0000000..dc120e1
--- /dev/null
+++ b/src/imgui_helper.cpp
@@ -0,0 +1,90 @@
+// 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(project_state *State, ImVec2 MousePos, ImVec2 Min, ImVec2 Max, int Direction)
+{
+    if (Direction & 1) {
+        if (MousePos.x < Min.x) {
+            State->Warp_WantSetPos = true;
+            State->Warp_PositionToSet = ImVec2(Max.x - 5, MousePos.y);
+            State->Warp_PositionInitial = MousePos.x;
+            State->Warp_Direction = 0;
+        }
+        if (MousePos.x > Max.x) {
+            State->Warp_WantSetPos = true;
+            State->Warp_PositionToSet = ImVec2(Min.x + 5, MousePos.y);
+            State->Warp_PositionInitial = MousePos.x;
+            State->Warp_Direction = 1;
+        }
+    }
+    if (Direction & 2) {
+        if (MousePos.y < Min.y) {
+            State->Warp_WantSetPos = true;
+            State->Warp_PositionToSet = ImVec2(MousePos.x, Max.y - 5);
+            State->Warp_PositionInitial = MousePos.y;
+            State->Warp_Direction = 2;
+        }
+        if (MousePos.y > Max.y) {
+            State->Warp_WantSetPos = true;
+            State->Warp_PositionToSet = ImVec2(MousePos.x, Min.y + 5);
+            State->Warp_PositionInitial = MousePos.y;
+            State->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(project_state *State, ImVec2 MousePos)
+{
+    if (State->Warp_Direction == 0) {
+        if (MousePos.x < State->Warp_PositionInitial) State->Warp_X--;
+    } else if (State->Warp_Direction == 1) {
+        if (MousePos.x > State->Warp_PositionInitial) State->Warp_X++;
+    } else if (State->Warp_Direction == 2) {
+        if (MousePos.y < State->Warp_PositionInitial) State->Warp_Y--;
+    } else if (State->Warp_Direction == 3) {
+        if (MousePos.y > State->Warp_PositionInitial) State->Warp_Y++;
+    } else {
+        Assert(0);
+    }
+}
+
+static bool32
+ImGui_TestBoxSelection_Point(ImVec2 Pos, ImGuiIO &io, bool32 *Test)
+{
+    bool32 Result = 0;
+    real32 Y_Top =    (io.MouseClickedPos[0].y < io.MousePos.y) ? io.MouseClickedPos[0].y : io.MousePos.y;
+    real32 Y_Bottom = (io.MouseClickedPos[0].y > io.MousePos.y) ? io.MouseClickedPos[0].y : io.MousePos.y;
+    real32 X_Left =   (io.MouseClickedPos[0].x < io.MousePos.x) ? io.MouseClickedPos[0].x : io.MousePos.x;
+    real32 X_Right =  (io.MouseClickedPos[0].x > io.MousePos.x) ? io.MouseClickedPos[0].x : io.MousePos.x;
+
+    if (Pos.y >= Y_Top  && Pos.y <= Y_Bottom &&
+        Pos.x >= X_Left && Pos.x <= X_Right)
+    {
+        if (!(*Test)) {
+            *Test = 1;
+            Result = 1;
+        }
+    } else if (!io.KeyShift) {
+        *Test = 0;
+    }
+    return Result;
+}