From d213c1a939710a26672e4711bbb1337610f32a37 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sun, 20 Nov 2022 20:05:07 -0800
Subject: [PATCH] fix selection regression caused by screen copy optimization

---
 src/Window.zig             |  4 ++--
 src/main.zig               |  1 -
 src/renderer/Metal.zig     |  9 +++++++-
 src/renderer/OpenGL.zig    |  9 +++++++-
 src/terminal/Selection.zig | 43 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 61 insertions(+), 5 deletions(-)

diff --git a/src/Window.zig b/src/Window.zig
index d0a467128..1609f5419 100644
--- a/src/Window.zig
+++ b/src/Window.zig
@@ -1650,13 +1650,13 @@ fn posToViewport(self: Window, xpos: f64, ypos: f64) terminal.point.Viewport {
 
             // Can be off the screen if the user drags it out, so max
             // it out on our available columns
-            break :x @min(x, self.io.terminal.cols - 1);
+            break :x @min(x, self.grid_size.columns - 1);
         },
 
         .y = if (ypos < 0) 0 else y: {
             const cell_height = @floatCast(f64, self.cell_size.height);
             const y = @floatToInt(usize, ypos / cell_height);
-            break :y @min(y, self.io.terminal.rows - 1);
+            break :y @min(y, self.grid_size.rows - 1);
         },
     };
 }
diff --git a/src/main.zig b/src/main.zig
index 2b245baa8..00d198f7b 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -203,7 +203,6 @@ test {
     _ = @import("TempDir.zig");
     _ = @import("font/main.zig");
     _ = @import("renderer.zig");
-    _ = @import("terminal/Terminal.zig");
     _ = @import("termio.zig");
     _ = @import("input.zig");
 
diff --git a/src/renderer/Metal.zig b/src/renderer/Metal.zig
index 21b68726c..c094d8ecb 100644
--- a/src/renderer/Metal.zig
+++ b/src/renderer/Metal.zig
@@ -458,10 +458,17 @@ pub fn render(
         );
         errdefer screen_copy.deinit();
 
+        // Convert our selection to viewport points because we copy only
+        // the viewport above.
+        const selection: ?terminal.Selection = if (state.terminal.selection) |sel|
+            sel.toViewport(&state.terminal.screen)
+        else
+            null;
+
         break :critical .{
             .bg = self.background,
             .devmode = if (state.devmode) |dm| dm.visible else false,
-            .selection = state.terminal.selection,
+            .selection = selection,
             .screen = screen_copy,
             .draw_cursor = self.cursor_visible and state.terminal.screen.viewportIsBottom(),
         };
diff --git a/src/renderer/OpenGL.zig b/src/renderer/OpenGL.zig
index d36670917..1302979ef 100644
--- a/src/renderer/OpenGL.zig
+++ b/src/renderer/OpenGL.zig
@@ -593,11 +593,18 @@ pub fn render(
         );
         errdefer screen_copy.deinit();
 
+        // Convert our selection to viewport points because we copy only
+        // the viewport above.
+        const selection: ?terminal.Selection = if (state.terminal.selection) |sel|
+            sel.toViewport(&state.terminal.screen)
+        else
+            null;
+
         break :critical .{
             .gl_bg = self.background,
             .devmode_data = devmode_data,
             .active_screen = state.terminal.active_screen,
-            .selection = state.terminal.selection,
+            .selection = selection,
             .screen = screen_copy,
             .draw_cursor = self.cursor_visible and state.terminal.screen.viewportIsBottom(),
         };
diff --git a/src/terminal/Selection.zig b/src/terminal/Selection.zig
index 8edf90215..973e1ab67 100644
--- a/src/terminal/Selection.zig
+++ b/src/terminal/Selection.zig
@@ -4,6 +4,7 @@ const Selection = @This();
 
 const std = @import("std");
 const point = @import("point.zig");
+const Screen = @import("Screen.zig");
 const ScreenPoint = point.ScreenPoint;
 
 /// Start and end of the selection. There is no guarantee that
@@ -13,6 +14,25 @@ const ScreenPoint = point.ScreenPoint;
 start: ScreenPoint,
 end: ScreenPoint,
 
+/// Converts a selection screen points to viewport points (still typed
+/// as ScreenPoints) if the selection is present within the viewport
+/// of the screen.
+pub fn toViewport(self: Selection, screen: *const Screen) ?Selection {
+    const top = (point.Viewport{ .x = 0, .y = 0 }).toScreen(screen);
+    const bot = (point.Viewport{ .x = 0, .y = screen.rows - 1 }).toScreen(screen);
+
+    // If our selection isn't within the viewport, do nothing.
+    if (!self.within(top, bot)) return null;
+
+    // Convert
+    const start = self.start.toViewport(screen);
+    const end = self.end.toViewport(screen);
+    return Selection{
+        .start = .{ .x = start.x, .y = start.y },
+        .end = .{ .x = end.x, .y = end.y },
+    };
+}
+
 /// Returns true if the selection contains the given point.
 ///
 /// This recalculates top left and bottom right each call. If you have
@@ -40,6 +60,15 @@ pub fn contains(self: Selection, p: ScreenPoint) bool {
     return p.y > tl.y and p.y < br.y;
 }
 
+/// Returns true if the selection contains any of the points between
+/// (and including) the start and end. The x values are ignored this is
+/// just a section match
+pub fn within(self: Selection, start: ScreenPoint, end: ScreenPoint) bool {
+    const tl = self.topLeft();
+    const br = self.bottomRight();
+    return tl.y >= start.y and br.y <= end.y;
+}
+
 /// Returns true if the selection contains the row of the given point,
 /// regardless of the x value.
 pub fn containsRow(self: Selection, p: ScreenPoint) bool {
@@ -116,3 +145,17 @@ test "Selection: contains" {
         try testing.expect(!sel.contains(.{ .x = 12, .y = 1 }));
     }
 }
+
+test "Selection: within" {
+    const testing = std.testing;
+    {
+        const sel: Selection = .{
+            .start = .{ .x = 5, .y = 1 },
+            .end = .{ .x = 3, .y = 2 },
+        };
+
+        try testing.expect(sel.within(.{ .x = 6, .y = 0 }, .{ .x = 6, .y = 3 }));
+        try testing.expect(sel.within(.{ .x = 3, .y = 1 }, .{ .x = 6, .y = 3 }));
+        try testing.expect(sel.within(.{ .x = 3, .y = 0 }, .{ .x = 6, .y = 2 }));
+    }
+}