Lay out the overlay panels in a fixed 3-column scheme

Panels used to Begin at cascade positions, so they overlapped and clipped. A new
apply_panel_layout() in app_chrome positions/sizes each panel from the main
viewport work area (ImGuiCond_FirstUseEver, still movable): Injection left column
full height (room for hook diagnostics), Controllers/Video/Audio stacked in the
center column, Log right edge full height (max room for the log stream). Added a
"View -> Reset layout" menu item (request_layout_reset / apply_layout_end_frame
re-apply the defaults once via ImGuiCond_Always). Each panel now calls
apply_panel_layout(Panel::X) instead of its own ad-hoc SetNextWindowPos/Size.

Verified live: captured the host overlay -- Injection (left, full height),
Controllers/Video/Audio (center stack), Log (right, full height), no overlap among
the panels. x64 build + ctest green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

host/src/ui/app_chrome.cpp

@@ -1,5 +1,6 @@
 #include "ui/app_chrome.hpp"
 
+#include <algorithm>
 #include <cstdio>
 
 #include "imgui.h"
@@ -7,6 +8,72 @@
 namespace coop
 {
 
+namespace
+{
+// Set by "View -> Reset layout"; true for the one frame in which panels re-apply
+// their default position/size, then cleared by apply_layout_end_frame().
+bool g_layout_reset = false;
+} // namespace
+
+void request_layout_reset()
+{
+	g_layout_reset = true;
+}
+
+void apply_layout_end_frame()
+{
+	g_layout_reset = false;
+}
+
+void apply_panel_layout(Panel panel)
+{
+	const ImGuiViewport* vp = ImGui::GetMainViewport();
+	const ImVec2 o = vp->WorkPos;  // below the main menu bar
+	const ImVec2 s = vp->WorkSize;
+	const float m = 12.0f;   // outer margin
+	const float gap = 10.0f; // between panels
+
+	const float left_w = 440.0f;  // Injection (window list + hook diagnostics)
+	const float right_w = 380.0f; // Log
+	const float center_x = o.x + m + left_w + gap;
+	const float right_x = o.x + s.x - right_w - m;
+	const float center_w = std::max(360.0f, right_x - gap - center_x);
+	const float full_h = std::max(200.0f, s.y - 2.0f * m);
+	const float ctrl_h = 210.0f; // Controllers
+	const float vid_h = 250.0f;  // Video mirror
+	const float audio_y = o.y + m + ctrl_h + gap + vid_h + gap;
+	const float bottom = o.y + m + full_h;
+
+	ImVec2 pos, size;
+	switch (panel)
+	{
+	case Panel::Injection:
+		pos = ImVec2(o.x + m, o.y + m);
+		size = ImVec2(left_w, full_h);
+		break;
+	case Panel::Controllers:
+		pos = ImVec2(center_x, o.y + m);
+		size = ImVec2(center_w, ctrl_h);
+		break;
+	case Panel::Video:
+		pos = ImVec2(center_x, o.y + m + ctrl_h + gap);
+		size = ImVec2(center_w, vid_h);
+		break;
+	case Panel::Audio:
+		pos = ImVec2(center_x, audio_y);
+		size = ImVec2(center_w, std::max(180.0f, bottom - audio_y));
+		break;
+	case Panel::Log:
+		pos = ImVec2(right_x, o.y + m);
+		size = ImVec2(right_w, full_h);
+		break;
+	}
+
+	const ImGuiCond cond = g_layout_reset ? ImGuiCond_Always : ImGuiCond_FirstUseEver;
+	ImGui::SetNextWindowPos(pos, cond);
+	ImGui::SetNextWindowSize(size, cond);
+}
+
 float draw_main_menu_bar(UiState& ui, const FrameStats& stats)
 {
 	float height = 0.0f;
@@ -27,6 +94,10 @@ float draw_main_menu_bar(UiState& ui, const FrameStats& stats)
 		ImGui::MenuItem("Log", nullptr, &ui.show_log);
 		ImGui::Separator();
 		ImGui::MenuItem("Debug details", nullptr, &ui.debug_details);
+		if (ImGui::MenuItem("Reset layout"))
+		{
+			request_layout_reset();
+		}
 		ImGui::EndMenu();
 	}
 

host/src/ui/app_chrome.hpp

@@ -22,6 +22,27 @@ struct UiState
 	bool debug_details = false; // off = general status; on = full diagnostics
 };
 
+// The overlay panels, for the shared default layout below.
+enum class Panel
+{
+	Injection,   // left column, full height (room for hook diagnostics)
+	Controllers, // center column, top
+	Video,       // center column, below Controllers
+	Audio,       // center column, below Video
+	Log,         // right column, full height (max room for the log stream)
+};
+
+// Position + size the next ImGui window per the default 3-column layout, so panels
+// open without overlapping or needing a manual resize. First-use only, unless a
+// layout reset was just requested (then it re-applies once). Call right before the
+// panel's ImGui::Begin.
+void apply_panel_layout(Panel panel);
+
+// "View -> Reset layout" sets this; it forces apply_panel_layout to re-place every
+// panel on the next frame. apply_layout_end_frame() clears it after the panels draw.
+void request_layout_reset();
+void apply_layout_end_frame();
+
 // Rolling frame-timing over a ~1 s window, recomputed each window so the status
 // bar can show a stable FPS plus the min/max frame time (jitter) underneath it.
 class FrameStats