From 71f1f35cfcd90ff5c48c9751895fcd632fd63398 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 22 Aug 2023 12:15:51 -0700
Subject: [PATCH] terminal/kitty-gfx: move cursor after image placement

---
 src/terminal/Terminal.zig            |  7 ++++
 src/terminal/kitty/graphics_exec.zig | 53 +++++++++++++++++++++++++++-
 src/termio/Exec.zig                  | 16 ++++++---
 3 files changed, 70 insertions(+), 6 deletions(-)

diff --git a/src/terminal/Terminal.zig b/src/terminal/Terminal.zig
index 93a380ca9..badb81a96 100644
--- a/src/terminal/Terminal.zig
+++ b/src/terminal/Terminal.zig
@@ -63,6 +63,10 @@ tabstops: Tabstops,
 rows: usize,
 cols: usize,
 
+/// The size of the screen in pixels. This is used for pty events and images
+width_px: u32 = 0,
+height_px: u32 = 0,
+
 /// The current scrolling region.
 scrolling_region: ScrollingRegion,
 
@@ -305,6 +309,9 @@ pub fn resize(self: *Terminal, alloc: Allocator, cols_req: usize, rows: usize) !
     else
         cols_req;
 
+    // If our cols/rows didn't change then we're done
+    if (self.cols == cols and self.rows == rows) return;
+
     // Resize our tabstops
     // TODO: use resize, but it doesn't set new tabstops
     if (self.cols != cols) {
diff --git a/src/terminal/kitty/graphics_exec.zig b/src/terminal/kitty/graphics_exec.zig
index 277d808b3..380205b81 100644
--- a/src/terminal/kitty/graphics_exec.zig
+++ b/src/terminal/kitty/graphics_exec.zig
@@ -19,7 +19,6 @@ const log = std.log.scoped(.kitty_gfx);
 // - terminal state around deleting images (i.e. CSI J)
 // - terminal state around deleting placements (i.e. scrolling)
 // (not exhaustive, almost every op is ignoring additional config)
-
 /// Execute a Kitty graphics command against the given terminal. This
 /// will never fail, but the response may indicate an error and the
 /// terminal state may not be updated to reflect the command. This will
@@ -175,6 +174,58 @@ fn display(
         return result;
     };
 
+    // Cursor needs to move after placement
+    switch (d.cursor_movement) {
+        .none => {},
+        .after => {
+            // Determine the rectangle of the image in grid cells
+            const image_grid_size: struct {
+                columns: u32,
+                rows: u32,
+            } = grid_size: {
+                // Calculate our cell size.
+                const terminal_width_f64: f64 = @floatFromInt(terminal.width_px);
+                const terminal_height_f64: f64 = @floatFromInt(terminal.height_px);
+                const grid_columns_f64: f64 = @floatFromInt(terminal.cols);
+                const grid_rows_f64: f64 = @floatFromInt(terminal.rows);
+                const cell_width_f64 = terminal_width_f64 / grid_columns_f64;
+                const cell_height_f64 = terminal_height_f64 / grid_rows_f64;
+
+                // Calculate our image size in grid cells
+                const width_f64: f64 = @floatFromInt(img.width);
+                const height_f64: f64 = @floatFromInt(img.height);
+                const width_cells: u32 = @intFromFloat(@ceil(width_f64 / cell_width_f64));
+                const height_cells: u32 = @intFromFloat(@ceil(height_f64 / cell_height_f64));
+
+                break :grid_size .{ .columns = width_cells, .rows = height_cells };
+            };
+            log.warn("terminal width={} height={} image_grid={}", .{
+                terminal.width_px,
+                terminal.height_px,
+                image_grid_size,
+            });
+
+            // If we are moving beneath the screen we need to scroll.
+            // TODO: handle scroll regions
+            var new_y = terminal.screen.cursor.y + image_grid_size.rows;
+            if (new_y >= terminal.rows) {
+                const scroll_amount = (new_y + 1) - terminal.rows;
+                terminal.screen.scroll(.{ .screen = @intCast(scroll_amount) }) catch |err| {
+                    // If this failed we just warn, the screen will just be in a
+                    // weird state but nothing fatal.
+                    log.warn("scroll for image failed: {}", .{err});
+                };
+                new_y = terminal.rows - 1;
+            }
+
+            // Move the cursor
+            terminal.setCursorPos(
+                terminal.screen.cursor.x + image_grid_size.columns,
+                new_y,
+            );
+        },
+    }
+
     return result;
 }
 
diff --git a/src/termio/Exec.zig b/src/termio/Exec.zig
index 94f53d3ba..562961237 100644
--- a/src/termio/Exec.zig
+++ b/src/termio/Exec.zig
@@ -103,6 +103,8 @@ pub fn init(alloc: Allocator, opts: termio.Options) !Exec {
     );
     errdefer term.deinit(alloc);
     term.color_palette = opts.config.palette;
+    term.width_px = opts.screen_size.width;
+    term.height_px = opts.screen_size.height;
 
     var subprocess = try Subprocess.init(alloc, opts);
     errdefer subprocess.deinit();
@@ -255,10 +257,6 @@ pub fn resize(
     const padded_size = screen_size.subPadding(padding);
     try self.subprocess.resize(grid_size, padded_size);
 
-    // If our grid size didn't change, then we don't need to change
-    // the underlying terminal.
-    if (grid_size.equals(self.grid_size)) return;
-
     // Update our cached grid size
     self.grid_size = grid_size;
 
@@ -268,7 +266,15 @@ pub fn resize(
         defer self.renderer_state.mutex.unlock();
 
         // Update the size of our terminal state
-        try self.terminal.resize(self.alloc, grid_size.columns, grid_size.rows);
+        try self.terminal.resize(
+            self.alloc,
+            grid_size.columns,
+            grid_size.rows,
+        );
+
+        // Update our pixel sizes
+        self.terminal.width_px = screen_size.width;
+        self.terminal.height_px = screen_size.height;
     }
 }