terminal/kitty-gfx: start working on placements

src/terminal/kitty/graphics_command.zig

@@ -294,6 +294,15 @@ pub const Command = struct {
         };
     }
 
+    /// Returns the display data if it has any.
+    pub fn display(self: Command) ?Display {
+        return switch (self.control) {
+            .display => |d| d,
+            .transmit_and_display => |t| t.display,
+            else => null,
+        };
+    }
+
     pub fn deinit(self: Command, alloc: Allocator) void {
         if (self.data.len > 0) alloc.free(self.data);
     }
@@ -399,6 +408,7 @@ pub const Transmission = struct {
 pub const Display = struct {
     image_id: u32 = 0, // i
     image_number: u32 = 0, // I
+    placement_id: u32 = 0, // p
     x: u32 = 0, // x
     y: u32 = 0, // y
     width: u32 = 0, // w
@@ -427,6 +437,10 @@ pub const Display = struct {
             result.image_number = v;
         }
 
+        if (kv.get('p')) |v| {
+            result.placement_id = v;
+        }
+
         if (kv.get('x')) |v| {
             result.x = v;
         }

src/terminal/kitty/graphics_exec.zig

@@ -111,10 +111,18 @@ fn display(
     terminal: *Terminal,
     cmd: *Command,
 ) Response {
+    const d = cmd.display().?;
+    var result: Response = .{
+        .id = d.image_id,
+        .image_number = d.image_number,
+        .placement_id = d.placement_id,
+    };
+
+    // TODO
+
     _ = alloc;
     _ = terminal;
-    _ = cmd;
-    return .{};
+    return result;
 }
 
 /// A combination of transmit and display. Nothing special.
@@ -138,7 +146,7 @@ fn loadAndAddImage(
     errdefer img.deinit(alloc);
 
     // Store our image
-    try terminal.screen.kitty_images.add(alloc, img);
+    try terminal.screen.kitty_images.addImage(alloc, img);
 
     return img;
 }

src/terminal/kitty/graphics_image.zig

@@ -10,6 +10,7 @@ const max_dimension = 10000;
 
 pub const Image = struct {
     id: u32 = 0,
+    number: u32 = 0,
     data: []const u8,
 
     pub const Error = error{
@@ -58,6 +59,7 @@ pub const Image = struct {
 
         return Image{
             .id = t.image_id,
+            .number = t.image_number,
             .data = data,
         };
     }

src/terminal/kitty/graphics_storage.zig

@@ -3,35 +3,72 @@ const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const ArenaAllocator = std.heap.ArenaAllocator;
 
-const Image = @import("graphics_image.zig").Image;
+const point = @import("../point.zig");
 const command = @import("graphics_command.zig");
+const Image = @import("graphics_image.zig").Image;
 const Command = command.Command;
+const ScreenPoint = point.ScreenPoint;
 
 /// An image storage is associated with a terminal screen (i.e. main
 /// screen, alt screen) and contains all the transmitted images and
 /// placements.
 pub const ImageStorage = struct {
-    /// The hash map type used to store our images. The key is the image ID
-    /// and the value is the image itself.
-    ///
-    /// Note that the image ID is optional when transmitting images, in
-    /// which case the image ID is always 0.
-    const HashMap = std.AutoHashMapUnmanaged(u32, Image);
+    const ImageMap = std.AutoHashMapUnmanaged(u32, Image);
+    const PlacementMap = std.AutoHashMapUnmanaged(PlacementKey, Placement);
 
     /// The set of images that are currently known.
-    images: HashMap = .{},
+    images: ImageMap = .{},
+
+    /// The set of placements for loaded images.
+    placements: PlacementMap = .{},
+
+    pub fn deinit(self: *ImageStorage, alloc: Allocator) void {
+        var it = self.images.iterator();
+        while (it.next()) |kv| kv.value_ptr.deinit(alloc);
+
+        self.images.deinit(alloc);
+        self.placements.deinit(alloc);
+    }
 
     /// Add an already-loaded image to the storage. This will automatically
     /// free any existing image with the same ID.
-    pub fn add(self: *ImageStorage, alloc: Allocator, img: Image) !void {
+    pub fn addImage(self: *ImageStorage, alloc: Allocator, img: Image) Allocator.Error!void {
         const gop = try self.images.getOrPut(alloc, img.id);
         if (gop.found_existing) gop.value_ptr.deinit(alloc);
         gop.value_ptr.* = img;
     }
 
-    pub fn deinit(self: *ImageStorage, alloc: Allocator) void {
-        var it = self.images.iterator();
-        while (it.next()) |kv| kv.value_ptr.deinit(alloc);
-        self.images.deinit(alloc);
+    /// Add a placement for a given image. The caller must verify in advance
+    /// the image exists to prevent memory corruption.
+    pub fn addPlacement(
+        self: *ImageStorage,
+        alloc: Allocator,
+        image_id: u32,
+        placement_id: u32,
+        p: Placement,
+    ) !void {
+        assert(self.images.get(image_id) != null);
+
+        const key: PlacementKey = .{ .image_id = image_id, .placement_id = placement_id };
+        const gop = try self.placements.getOrPut(alloc, key);
+        gop.value_ptr.* = p;
     }
+
+    /// Get an image by its ID. If the image doesn't exist, null is returned.
+    pub fn imageById(self: *ImageStorage, image_id: u32) ?Image {
+        return self.images.get(image_id);
+    }
+
+    /// Every placement is uniquely identified by the image ID and the
+    /// placement ID. If an image ID isn't specified it is assumed to be 0.
+    /// Likewise, if a placement ID isn't specified it is assumed to be 0.
+    pub const PlacementKey = struct {
+        image_id: u32,
+        placement_id: u32,
+    };
+
+    pub const Placement = struct {
+        /// The location of the image on the screen.
+        point: ScreenPoint,
+    };
 };