From dfefe953fcb1b647e5fd9fac0013a634b8bcff65 Mon Sep 17 00:00:00 2001
From: Chris Marchesi <chrism@vancluevertech.com>
Date: Tue, 19 Dec 2023 11:36:05 -0800
Subject: [PATCH] Powerline: add trapezoid rendering

This adds Powerline rendering for the trapezoid characters (E0D2 and
E0D4).

This is the last of the Powerline additions for now. These are the
shapes that 1) render the most egregiously with stock fonts (off-center,
bleeding background, visible gaps), and 2) are simple enough to be
rendered without resorting to more complex measures like embedding SVG.
---
 src/font/sprite/Face.zig      |   2 +
 src/font/sprite/Powerline.zig | 115 ++++++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+)

diff --git a/src/font/sprite/Face.zig b/src/font/sprite/Face.zig
index d897b1341..86dd70c71 100644
--- a/src/font/sprite/Face.zig
+++ b/src/font/sprite/Face.zig
@@ -181,6 +181,8 @@ const Kind = enum {
             0xE0BA,
             0xE0BC,
             0xE0BE,
+            0xE0D2,
+            0xE0D4,
             => .powerline,
 
             else => null,
diff --git a/src/font/sprite/Powerline.zig b/src/font/sprite/Powerline.zig
index 642ecdad2..a6551b5f3 100644
--- a/src/font/sprite/Powerline.zig
+++ b/src/font/sprite/Powerline.zig
@@ -11,6 +11,7 @@ const std = @import("std");
 const Allocator = std.mem.Allocator;
 
 const font = @import("../main.zig");
+const Trapezoid = @import("canvas.zig").Trapezoid;
 
 const log = std.log.scoped(.powerline_font);
 
@@ -97,6 +98,11 @@ fn draw(self: Powerline, alloc: Allocator, canvas: *font.sprite.Canvas, cp: u32)
         0xE0B6,
         => try self.draw_half_circle(alloc, canvas, cp),
 
+        // Mirrored top-down trapezoids
+        0xE0D2,
+        0xE0D4,
+        => try self.draw_trapezoid_top_bottom(canvas, cp),
+
         else => return error.InvalidCodepoint,
     }
 }
@@ -397,6 +403,113 @@ fn draw_half_circle(self: Powerline, alloc: Allocator, canvas: *font.sprite.Canv
     }
 }
 
+fn draw_trapezoid_top_bottom(self: Powerline, canvas: *font.sprite.Canvas, cp: u32) !void {
+    const t_top: Trapezoid = if (cp == 0xE0D4)
+        .{
+            .top = 0,
+            .bottom = @intCast(self.height / 2 - self.height / 20),
+            .left = .{
+                .p1 = .{
+                    .x = 0,
+                    .y = 0,
+                },
+                .p2 = .{
+                    .x = @intCast(self.width - self.width / 3),
+                    .y = @intCast(self.height / 2 - self.height / 20),
+                },
+            },
+            .right = .{
+                .p1 = .{
+                    .x = @intCast(self.width),
+                    .y = 0,
+                },
+                .p2 = .{
+                    .x = @intCast(self.width),
+                    .y = @intCast(self.height / 2 - self.height / 20),
+                },
+            },
+        }
+    else
+        .{
+            .top = 0,
+            .bottom = @intCast(self.height / 2 - self.height / 20),
+            .left = .{
+                .p1 = .{
+                    .x = 0,
+                    .y = 0,
+                },
+                .p2 = .{
+                    .x = 0,
+                    .y = @intCast(self.height / 2 - self.height / 20),
+                },
+            },
+            .right = .{
+                .p1 = .{
+                    .x = @intCast(self.width),
+                    .y = 0,
+                },
+                .p2 = .{
+                    .x = @intCast(self.width / 3),
+                    .y = @intCast(self.height / 2 - self.height / 20),
+                },
+            },
+        };
+
+    const t_bottom: Trapezoid = if (cp == 0xE0D4)
+        .{
+            .top = @intCast(self.height / 2 + self.height / 20),
+            .bottom = @intCast(self.height),
+            .left = .{
+                .p1 = .{
+                    .x = @intCast(self.width - self.width / 3),
+                    .y = @intCast(self.height / 2 + self.height / 20),
+                },
+                .p2 = .{
+                    .x = 0,
+                    .y = @intCast(self.height),
+                },
+            },
+            .right = .{
+                .p1 = .{
+                    .x = @intCast(self.width),
+                    .y = @intCast(self.height / 2 + self.height / 20),
+                },
+                .p2 = .{
+                    .x = @intCast(self.width),
+                    .y = @intCast(self.height),
+                },
+            },
+        }
+    else
+        .{
+            .top = @intCast(self.height / 2 + self.height / 20),
+            .bottom = @intCast(self.height),
+            .left = .{
+                .p1 = .{
+                    .x = 0,
+                    .y = @intCast(self.height / 2 + self.height / 20),
+                },
+                .p2 = .{
+                    .x = 0,
+                    .y = @intCast(self.height),
+                },
+            },
+            .right = .{
+                .p1 = .{
+                    .x = @intCast(self.width / 3),
+                    .y = @intCast(self.height / 2 + self.height / 20),
+                },
+                .p2 = .{
+                    .x = @intCast(self.width),
+                    .y = @intCast(self.height),
+                },
+            },
+        };
+
+    canvas.trapezoid(t_top);
+    canvas.trapezoid(t_bottom);
+}
+
 test "all" {
     const testing = std.testing;
     const alloc = testing.allocator;
@@ -410,6 +523,8 @@ test "all" {
         0xE0BE,
         0xE0B4,
         0xE0B6,
+        0xE0D2,
+        0xE0D4,
     };
     for (cps) |cp| {
         var atlas_greyscale = try font.Atlas.init(alloc, 512, .greyscale);