GPU-based font rendering (keming edition)

src/Game.zig

@@ -16,6 +16,7 @@ const Chunk = @import("Chunk.zig");
 const Chunks = @import("Chunks.zig");
 const CommandBuffer = @import("engine/CommandBuffer.zig");
 const Engine = @import("engine/Engine.zig");
+const Fonts = @import("engine/Fonts.zig");
 const Iterator2 = math.Iterator2;
 const Materials = @import("engine/Materials.zig");
 const Player = @import("Player.zig");
@@ -47,6 +48,7 @@ blocks: Blocks,
 chunks: Chunks,
 skybox: Skybox,
 player: Player,
+font: Fonts.Id,
 
 const max_textures = 1024;
 const max_point_lights = 1024;
@@ -70,6 +72,7 @@ pub fn init() !Game {
     const swapchain = ctx.swapchain;
     const textures = ctx.textures;
     const materials = ctx.materials;
+    const fonts = ctx.fonts;
     const gui = ctx.gui;
 
     var blocks = try Blocks.init();
@@ -137,7 +140,7 @@ pub fn init() !Game {
                 .descriptor_type = .sampled_image,
                 .descriptor_count = max_textures,
                 .stage_flags = .{ .vertex_bit = true, .fragment_bit = true },
-                .flags = .{ .variable_descriptor_count_bit = true },
+                .flags = .{ .variable_descriptor_count_bit = true }, // TODO Get rid of this AND somehow integrate with Textures module?
             },
         },
     });
@@ -442,6 +445,13 @@ pub fn init() !Game {
     const block_stone = try blocks.getOrLoad("Stone.json");
     const block_bedrock = try blocks.getOrLoad("Bedrock.json");
 
+    const font_id = try fonts.load("FiraMono-Regular.ttf", .{
+        .codepoint_ranges = &.{
+            .{ .start = 32, .end = 127 },
+        },
+        .name = "EB Garamond Regular",
+    });
+
     // VOLATILE Load all assets before this point
 
     const descriptor_images = try allocator_frame.alloc(vk.DescriptorImageInfo, textures.array.items.len);
@@ -619,6 +629,8 @@ pub fn init() !Game {
     var skybox = try Skybox.load("skybox.hdr", 512, global_uniforms.buffer);
     errdefer skybox.deinit();
 
+    const font = &fonts.array.items[@intFromEnum(font_id)];
+
     // TODO This coupling is not elegant - the game must provide the GUI with
     // uniform buffer for globals. Maybe GUI should just use their own global
     // uniform buffer not for any other reason than decoupling. After all, GUI
@@ -641,6 +653,66 @@ pub fn init() !Game {
                     },
                 },
             },
+            .{
+                .dst_set = gui.text_descriptor_set,
+                .dst_binding = 0,
+                .dst_array_element = 0,
+                .descriptor_type = .uniform_buffer,
+                .descriptor_infos = .{
+                    .buffer = &.{
+                        .{
+                            .buffer = global_uniforms.buffer,
+                            .offset = 0,
+                            .range = vk.WHOLE_SIZE,
+                        },
+                    },
+                },
+            },
+            .{
+                .dst_set = gui.text_descriptor_set,
+                .dst_binding = 2,
+                .dst_array_element = @intFromEnum(font_id),
+                .descriptor_type = .storage_buffer,
+                .descriptor_infos = .{
+                    .buffer = &.{
+                        .{
+                            .buffer = font.glyph_data.buffer,
+                            .offset = 0,
+                            .range = vk.WHOLE_SIZE,
+                        },
+                    },
+                },
+            },
+            .{
+                .dst_set = gui.text_descriptor_set,
+                .dst_binding = 3,
+                .dst_array_element = @intFromEnum(font_id),
+                .descriptor_type = .storage_buffer,
+                .descriptor_infos = .{
+                    .buffer = &.{
+                        .{
+                            .buffer = font.control_points.buffer,
+                            .offset = 0,
+                            .range = vk.WHOLE_SIZE,
+                        },
+                    },
+                },
+            },
+            .{
+                .dst_set = gui.text_descriptor_set,
+                .dst_binding = 4,
+                .dst_array_element = @intFromEnum(font_id),
+                .descriptor_type = .storage_buffer,
+                .descriptor_infos = .{
+                    .buffer = &.{
+                        .{
+                            .buffer = font.band_data.buffer,
+                            .offset = 0,
+                            .range = vk.WHOLE_SIZE,
+                        },
+                    },
+                },
+            },
         },
     });
 
@@ -667,6 +739,7 @@ pub fn init() !Game {
         .chunks = .{ .chunks = chunks },
         .skybox = skybox,
         .player = .init(player_position_sv, 0, 0),
+        .font = font_id,
     };
 }
 
@@ -741,6 +814,43 @@ pub fn update(self: *Game, dt: f32) void {
         .border_radius_px = 0,
     });
 
+    {
+        const margin: f16 = 8;
+        const font_size: f32 = 16;
+
+        const player_position_sv = self.player.position_sv;
+
+        gui.pushBox(.{
+            .background_color = .init(0, 0, 0, 0.75),
+            .border_color = .init(0, 0, 0, 1),
+            .position_sspx = .init(0, 0),
+            .size_px = .init(157, 4 * margin + 3 * font_size),
+            .border_width_px = 0,
+            .border_radius_px = 0,
+        });
+
+        gui.printLine("X {X:0>8}", .{@as(u32, @bitCast(player_position_sv.x))}, .{
+            .position_sspx = .init(margin, margin + font_size),
+            .font_id = self.font,
+            .cap_height_px = font_size,
+            .color = .init(1, 1, 1, 1),
+        });
+
+        gui.printLine("Y {X:0>8}", .{@as(u32, @bitCast(player_position_sv.y))}, .{
+            .position_sspx = .init(margin, 2 * (margin + font_size)),
+            .font_id = self.font,
+            .cap_height_px = font_size,
+            .color = .init(1, 1, 1, 1),
+        });
+
+        gui.printLine("Z {X:0>8}", .{@as(u32, @bitCast(player_position_sv.z))}, .{
+            .position_sspx = .init(margin, 3 * (margin + font_size)),
+            .font_id = self.font,
+            .cap_height_px = font_size,
+            .color = .init(1, 1, 1, 1),
+        });
+    }
+
     self.render() catch |err| {
         std.log.err("Failed to render: {s}", .{@errorName(err)});
         @panic("Frame update failed");