Add new background image modes

src/config.zig

@@ -30,8 +30,10 @@ pub const RepeatableFontVariation = Config.RepeatableFontVariation;
 pub const RepeatableString = Config.RepeatableString;
 pub const RepeatableStringMap = @import("config/RepeatableStringMap.zig");
 pub const RepeatablePath = Config.RepeatablePath;
+pub const SinglePath = Config.SinglePath;
 pub const ShellIntegrationFeatures = Config.ShellIntegrationFeatures;
 pub const WindowPaddingColor = Config.WindowPaddingColor;
+pub const BackgroundImageMode = Config.BackgroundImageMode;
 
 // Alternate APIs
 pub const CAPI = @import("config/CAPI.zig");

src/config/Config.zig

@@ -461,22 +461,22 @@ background: Color = .{ .r = 0x28, .g = 0x2C, .b = 0x34 },
 foreground: Color = .{ .r = 0xFF, .g = 0xFF, .b = 0xFF },
 
 /// Background image for the window.
-@"background-image": RepeatablePath = .{},
+@"background-image": SinglePath = .{},
 
 /// Background image opactity
-@"background-image-opacity": f32 = 0.0,
+@"background-image-opacity": f32 = 1.0,
 
 /// Background image mode to use.
 ///
-/// `aspect` keeps the aspect-ratio of the background image and `scaled` scales
-/// the image to fit the window. `aspect` is the default mode.
-///
 /// Valid values are:
 ///
-///   * `aspect`
+///   * `zoomed` - Image is scaled to fit the window, preserving aspect ratio.
-///   * `scaled`
+///   * `scaled` - Image is scaled to fill the window, not preserving aspect ratio.
+///   * `tiled` - Image is repeated horizontally and vertically to fill the window.
+///   * `centered` - Image is centered in the window and displayed 1-to-1 pixel
+///     scale, preserving both the aspect ratio and the image size.
 ///
-@"background-image-mode": BackgroundImageProgram.BackgroundMode = .aspect,
+@"background-image-mode": BackgroundImageMode = .zoomed,
 
 /// The foreground and background color for selection. If this is not set, then
 /// the selection color is just the inverted window background and foreground
@@ -4181,6 +4181,84 @@ pub const Palette = struct {
     }
 };
 
+/// Path is a path to a single file.
+pub const SinglePath = struct {
+    const Self = @This();
+
+    /// The actual value that is updated as we parse.
+    value: []const u8 = "",
+
+    /// Parse a single path.
+    pub fn parseCLI(self: *Self, alloc: Allocator, input: ?[]const u8) !void {
+        const value = input orelse return error.ValueRequired;
+        const copy = try alloc.dupe(u8, value);
+        self.value = copy;
+    }
+
+    /// Deep copy of the struct. Required by Config.
+    pub fn clone(self: Self, alloc: Allocator) Allocator.Error!Self {
+        const copy_path = try alloc.dupe(u8, self.value);
+        return .{
+            .value = copy_path,
+        };
+    }
+
+    /// Used by Formatter
+    pub fn formatEntry(self: Self, formatter: anytype) !void {
+        try formatter.formatEntry([]const u8, self.value);
+    }
+
+    pub fn expand(
+        self: *Self,
+        alloc: Allocator,
+        base: []const u8,
+        diags: *cli.DiagnosticList,
+    ) !void {
+        assert(std.fs.path.isAbsolute(base));
+        var dir = try std.fs.cwd().openDir(base, .{});
+        defer dir.close();
+
+        const path = self.value;
+
+        // If it is already absolute we can ignore it.
+        if (path.len == 0 or std.fs.path.isAbsolute(path)) return;
+
+        // If it isn't absolute, we need to make it absolute relative
+        // to the base.
+        var buf: [std.fs.max_path_bytes]u8 = undefined;
+        const abs = dir.realpath(path, &buf) catch |err| abs: {
+            if (err == error.FileNotFound) {
+                // The file doesn't exist. Try to resolve the relative path
+                // another way.
+                const resolved = try std.fs.path.resolve(alloc, &.{ base, path });
+                defer alloc.free(resolved);
+                @memcpy(buf[0..resolved.len], resolved);
+                break :abs buf[0..resolved.len];
+            }
+
+            try diags.append(alloc, .{
+                .message = try std.fmt.allocPrintZ(
+                    alloc,
+                    "error resolving file path {s}: {}",
+                    .{ path, err },
+                ),
+            });
+
+            // Blank this path so that we don't attempt to resolve it again
+            self.value = "";
+
+            return;
+        };
+
+        log.debug(
+            "expanding file path relative={s} abs={s}",
+            .{ path, abs },
+        );
+
+        self.value = try alloc.dupeZ(u8, abs);
+    }
+};
+
 /// RepeatableString is a string value that can be repeated to accumulate
 /// a list of strings. This isn't called "StringList" because I find that
 /// sometimes leads to confusion that it _accepts_ a list such as
@@ -6177,6 +6255,14 @@ pub const AlphaBlending = enum {
     }
 };
 
+/// See background-image-mode
+pub const BackgroundImageMode = enum(u8) {
+    zoomed = 0,
+    stretched = 1,
+    tiled = 2,
+    centered = 3,
+};
+
 /// See freetype-load-flag
 pub const FreetypeLoadFlags = packed struct {
     // The defaults here at the time of writing this match the defaults

src/renderer/OpenGL.zig

@@ -4,6 +4,7 @@ pub const OpenGL = @This();
 const std = @import("std");
 const builtin = @import("builtin");
 const glfw = @import("glfw");
+const wuffs = @import("wuffs");
 const assert = std.debug.assert;
 const testing = std.testing;
 const Allocator = std.mem.Allocator;
@@ -44,6 +45,9 @@ else
 const DrawMutex = if (single_threaded_draw) std.Thread.Mutex else void;
 const drawMutexZero: DrawMutex = if (DrawMutex == void) void{} else .{};
 
+/// The maximum size of a background image.
+const max_image_size = 400 * 1024 * 1024; // 400MB
+
 alloc: std.mem.Allocator,
 
 /// The configuration we need derived from the main config.
@@ -137,13 +141,13 @@ draw_mutex: DrawMutex = drawMutexZero,
 draw_background: terminal.color.RGB,
 
 /// The background image(s) to draw. Currentlly, we always draw the last image.
-background_image: configpkg.RepeatablePath,
+background_image: configpkg.SinglePath,
 
 /// The opacity of the background image. Not to be confused with background-opacity
 background_image_opacity: f32,
 
 /// The background image mode to use.
-background_image_mode: BackgroundImageProgram.BackgroundMode,
+background_image_mode: configpkg.BackgroundImageMode,
 
 /// The current background image to draw. If it is null, then we will not
 /// draw any background image.
@@ -295,9 +299,9 @@ pub const DerivedConfig = struct {
     cursor_opacity: f64,
     background: terminal.color.RGB,
     background_opacity: f64,
-    background_image: configpkg.RepeatablePath,
+    background_image: configpkg.SinglePath,
     background_image_opacity: f32,
-    background_image_mode: BackgroundImageProgram.BackgroundMode,
+    background_image_mode: configpkg.BackgroundImageMode,
     foreground: terminal.color.RGB,
     selection_background: ?terminal.color.RGB,
     selection_foreground: ?terminal.color.RGB,
@@ -824,14 +828,13 @@ pub fn updateFrame(
         }
 
         if (self.current_background_image == null and
-            self.background_image.value.items.len > 0)
+            self.background_image.value.len > 0)
         {
             if (single_threaded_draw) self.draw_mutex.lock();
             defer if (single_threaded_draw) self.draw_mutex.unlock();
             self.prepBackgroundImage() catch |err| switch (err) {
                 error.InvalidData => {
-                    log.warn("invalid image data", .{});
+                    log.warn("invalid image data, skipping", .{});
-                    self.current_background_image = null;
                 },
                 else => return err,
             };
@@ -1205,52 +1208,63 @@ fn prepKittyImage(
 /// Prepares the current background image for upload
 pub fn prepBackgroundImage(self: *OpenGL) !void {
     // If the user doesn't have a background image, do nothing...
-    const last_image = self.background_image.value.getLastOrNull() orelse return;
+    if (self.background_image.value.len == 0) return;
+    const path = self.background_image.value;
 
-    // Get the last background image
+    // Read the file content
-    const path = switch (last_image) {
+    const file_content = try self.readImageContent(path);
-        .optional, .required => |path| path,
+    defer self.alloc.free(file_content);
-    };
-    const command = terminal.kitty.graphics.Command{
-        .control = .{
-            .transmit = .{
-                .format = .png,
-                .medium = .file,
-                .width = 0,
-                .height = 0,
-                .compression = .none,
-                .image_id = 0,
-            },
-        },
-        .data = try self.alloc.dupe(u8, path),
-    };
-    defer command.deinit(self.alloc);
 
-    // Load the iamge
+    // Decode the png (currently, we only support png)
-    var loading = try terminal.kitty.graphics.LoadingImage.init(self.alloc, &command);
+    const decoded_image = try wuffs.png.decode(self.alloc, file_content);
-    defer loading.deinit(self.alloc);
+    defer self.alloc.free(decoded_image.data);
 
-    // Complete the image to get the final data
+    // Copy the data into the pending state
-    var image = try loading.complete(self.alloc);
+    const data = try self.alloc.dupe(u8, decoded_image.data);
-    defer image.deinit(self.alloc);
-
-    // Copy the data into the pending state.
-    const data = try self.alloc.dupe(u8, image.data);
     errdefer self.alloc.free(data);
-
     const pending: Image.Pending = .{
-        .width = image.width,
+        .width = decoded_image.width,
-        .height = image.height,
+        .height = decoded_image.height,
         .data = data.ptr,
     };
 
-    self.current_background_image = switch (image.format) {
+    // Store the image
-        .gray => .{ .pending_gray = pending },
+    self.current_background_image = .{ .pending_rgba = pending };
-        .gray_alpha => .{ .pending_gray_alpha = pending },
+}
-        .rgb => .{ .pending_rgb = pending },
+
-        .rgba => .{ .pending_rgba = pending },
+/// Reads the content of the given image path and returns it
-        .png => unreachable, // should be decoded by now
+pub fn readImageContent(self: *OpenGL, path: []const u8) ![]u8 {
+    // Open the file
+    var file = std.fs.cwd().openFile(path, .{}) catch |err| {
+        log.warn("failed to open file: {}", .{err});
+        return error.InvalidData;
     };
+    defer file.close();
+
+    // File must be a regular file
+    if (file.stat()) |stat| {
+        if (stat.kind != .file) {
+            log.warn("file is not a regular file kind={}", .{stat.kind});
+            return error.InvalidData;
+        }
+    } else |err| {
+        log.warn("failed to stat file: {}", .{err});
+        return error.InvalidData;
+    }
+
+    var buf_reader = std.io.bufferedReader(file.reader());
+    const reader = buf_reader.reader();
+
+    // Read the file
+    var managed = std.ArrayList(u8).init(self.alloc);
+    errdefer managed.deinit();
+    const size: usize = max_image_size;
+    reader.readAllArrayList(&managed, size) catch |err| {
+        log.warn("failed to read file: {}", .{err});
+        return error.InvalidData;
+    };
+
+    return managed.items;
 }
 
 /// rebuildCells rebuilds all the GPU cells from our CPU state. This is a

src/renderer/opengl/BackgroundImageProgram.zig

@@ -3,6 +3,7 @@ const BackgroundImageProgram = @This();
 
 const std = @import("std");
 const gl = @import("opengl");
+const configpkg = @import("../../config.zig");
 
 pub const Input = extern struct {
     /// vec2 terminal_size
@@ -10,13 +11,7 @@ pub const Input = extern struct {
     terminal_height: u32 = 0,
 
     /// uint mode
-    mode: BackgroundMode = .aspect,
+    mode: configpkg.BackgroundImageMode = .zoomed,
-};
-
-pub const BackgroundMode = enum(u8) {
-    aspect = 0,
-    scaled = 1,
-    _,
 };
 
 program: gl.Program,
@@ -63,7 +58,7 @@ pub fn init() !BackgroundImageProgram {
     var offset: usize = 0;
     try vbobind.attributeAdvanced(0, 2, gl.c.GL_UNSIGNED_INT, false, @sizeOf(Input), offset);
     offset += 2 * @sizeOf(u32);
-    try vbobind.attributeAdvanced(1, 2, gl.c.GL_UNSIGNED_BYTE, false, @sizeOf(Input), offset);
+    try vbobind.attributeIAdvanced(1, 1, gl.c.GL_UNSIGNED_BYTE, @sizeOf(Input), offset);
     offset += 1 * @sizeOf(u8);
     try vbobind.enableAttribArray(0);
     try vbobind.enableAttribArray(1);

src/renderer/shaders/bgimage.f.glsl

@@ -1,6 +1,12 @@
 #version 330 core
 
+const uint MODE_ZOOMED = 0u;
+const uint MODE_STRETCHED = 1u;
+const uint MODE_TILED = 2u;
+const uint MODE_CENTERED = 3u;
+
 in vec2 tex_coord;
+flat in uint mode;
 
 layout(location = 0) out vec4 out_FragColor;
 
@@ -8,6 +14,12 @@ uniform sampler2D image;
 uniform float opacity;
 
 void main() {
-	vec4 color = texture(image, tex_coord);
+	// Normalize the coordinate if we are tiling
+	vec2 norm_coord = tex_coord;
+	// if (mode == MODE_TILED) {
+	// 	norm_coord = fract(tex_coord);
+	// }
+	norm_coord = fract(tex_coord);
+	vec4 color = texture(image, norm_coord);
 	out_FragColor = vec4(color.rgb * color.a * opacity, color.a * opacity);
 }

src/renderer/shaders/bgimage.v.glsl

@@ -1,24 +1,37 @@
 #version 330 core
 
-const uint MODE_ASPECT = 0u;
+const uint MODE_ZOOMED = 0u;
-const uint MODE_SCALED = 1u;
+const uint MODE_STRETCHED = 1u;
+const uint MODE_TILED = 2u;
+const uint MODE_CENTERED = 3u;
 
 layout (location = 0) in vec2 terminal_size;
-layout (location = 1) in uint mode;
+layout (location = 1) in uint mode_in;
 
 out vec2 tex_coord;
+flat out uint mode;
+
 uniform sampler2D image;
 uniform mat4 projection;
 
 void main() {
+	// Set mode so that we can use it in the fragment shader
+	mode = mode_in;
+
+	// Calculate the position of the image
 	vec2 position;
 	position.x = (gl_VertexID == 0 || gl_VertexID == 1) ? 1. : 0.;
 	position.y = (gl_VertexID == 0 || gl_VertexID == 3) ? 0. : 1.;
 
+	// Get the size of the image
 	vec2 image_size = textureSize(image, 0);
+
+	// Handles the scale of the image relative to the terminal size
 	vec2 scale = vec2(1.0, 1.0);
+
 	switch (mode) {
-	case MODE_ASPECT:
+	case MODE_ZOOMED:
+		// If zoomed, we want to scale the image to fit the terminal
 		vec2 aspect_ratio = vec2(
 			terminal_size.x / terminal_size.y,
 			image_size.x / image_size.y
@@ -29,12 +42,24 @@ void main() {
 		else {
 			scale.y = aspect_ratio.x / aspect_ratio.y;
 		}
-	case MODE_SCALED:
+		break;
+	case MODE_CENTERED:
+		// If centered, the final scale of the image should match the actual
+		// size of the image and should be centered
+		scale.x = image_size.x / terminal_size.x;
+		scale.y = image_size.y / terminal_size.y;
+		break;
+	case MODE_STRETCHED:
+	case MODE_TILED:
+		// We don't need to do anything for stretched or tiled
 		break;
 	}
 
-	vec2 image_pos = terminal_size * position * scale;
+	vec2 final_image_size = terminal_size * position * scale;
 	vec2 offset = (terminal_size * (1.0 - scale)) / 2.0;
-	gl_Position = projection * vec4(image_pos.xy + offset, 0.0, 1.0);
+	gl_Position = projection * vec4(final_image_size.xy + offset, 0.0, 1.0);
 	tex_coord = position;
+	if (mode == MODE_TILED) {
+		tex_coord = position * terminal_size / image_size;
+	}
 }

src/terminal/kitty/graphics.zig

@@ -24,7 +24,6 @@ const storage = @import("graphics_storage.zig");
 pub const unicode = @import("graphics_unicode.zig");
 pub const Command = command.Command;
 pub const CommandParser = command.Parser;
-pub const LoadingImage = image.LoadingImage;
 pub const Image = image.Image;
 pub const ImageStorage = storage.ImageStorage;
 pub const RenderPlacement = render.Placement;