From a2c4f830b3e7ed7d6ab94df1ee677a908e3c5fb3 Mon Sep 17 00:00:00 2001
From: Joseph Adams <whitegolem@gmail.com>
Date: Thu, 13 Jan 2022 17:27:02 +0100
Subject: [PATCH] Enable use of higher options for underlining text.

In `Colored and styled underlines` it's proposed that the SGR codes
\e[4:4m and \e[4:5m are used to add a dotted or dashed underline to the
rendering context respectively. This commit prepares the necessary
changes to add the two additional underline style, while still rendering
them as a normal underline and curly underline.
---
 kitty/cell_vertex.glsl | 4 ++--
 kitty/cursor.c         | 4 ++--
 kitty/data-types.h     | 2 +-
 kitty/fonts/render.py  | 4 ++--
 kitty/shaders.c        | 2 +-
 5 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/kitty/cell_vertex.glsl b/kitty/cell_vertex.glsl
index e44c57053..af772a0c5 100644
--- a/kitty/cell_vertex.glsl
+++ b/kitty/cell_vertex.glsl
@@ -79,8 +79,8 @@ const uint COLOR_MASK = uint(0x4000);
 const uint ZERO = uint(0);
 const uint ONE = uint(1);
 const uint TWO = uint(2);
-const uint THREE = uint(3);
 const uint FOUR = uint(4);
+const uint SEVEN = uint(7);
 
 vec3 color_to_vec(uint c) {
     uint r, g, b;
@@ -193,7 +193,7 @@ void main() {
     foreground = choose_color(float(is_selected & ONE), selection_color, foreground);
     decoration_fg = choose_color(float(is_selected & ONE), selection_color, decoration_fg);
     // Underline and strike through (rendered via sprites)
-    underline_pos = choose_color(in_url, to_sprite_pos(pos, url_style, ZERO, ZERO), to_sprite_pos(pos, (text_attrs >> DECORATION_SHIFT) & THREE, ZERO, ZERO));
+    underline_pos = choose_color(in_url, to_sprite_pos(pos, url_style, ZERO, ZERO), to_sprite_pos(pos, (text_attrs >> DECORATION_SHIFT) & SEVEN, ZERO, ZERO));
     strike_pos = to_sprite_pos(pos, ((text_attrs >> STRIKE_SHIFT) & ONE) * FOUR, ZERO, ZERO);
 
     // Cursor
diff --git a/kitty/cursor.c b/kitty/cursor.c
index f129c438b..8c1aee84e 100644
--- a/kitty/cursor.c
+++ b/kitty/cursor.c
@@ -90,7 +90,7 @@ START_ALLOW_CASE_RANGE
             case 3:
                 self->italic = true;  break;
             case 4:
-                if (i < count) { self->decoration = MIN(3, params[i]); i++; }
+                if (i < count) { self->decoration = MIN(5, params[i]); i++; }
                 else self->decoration = 1;
                 break;
             case 7:
@@ -161,7 +161,7 @@ apply_sgr_to_cells(GPUCell *first_cell, unsigned int cell_count, int *params, un
                 S(italic, true);
             case 4: {
                 uint8_t val = 1;
-                if (i < count) { val = MIN(3, params[i]); i++; }
+                if (i < count) { val = MIN(5, params[i]); i++; }
                 S(decoration, val);
             }
             case 7:
diff --git a/kitty/data-types.h b/kitty/data-types.h
index 42287b00e..b04cb75c2 100644
--- a/kitty/data-types.h
+++ b/kitty/data-types.h
@@ -142,7 +142,7 @@ typedef struct {
 typedef union CellAttrs {
     struct {
         uint16_t width : 2;
-        uint16_t decoration : 2;
+        uint16_t decoration : 3;
         uint16_t bold : 1;
         uint16_t italic : 1;
         uint16_t reverse : 1;
diff --git a/kitty/fonts/render.py b/kitty/fonts/render.py
index 989497ab9..2c34de2b3 100644
--- a/kitty/fonts/render.py
+++ b/kitty/fonts/render.py
@@ -313,7 +313,7 @@ def render_special(
         t = underline_thickness
         if underline > 1:
             t = max(1, min(cell_height - underline_position - 1, t))
-        dl([add_line, add_line, add_dline, add_curl][underline], underline_position, t, cell_height)
+        dl([add_line, add_line, add_dline, add_curl, add_line, add_curl][underline], underline_position, t, cell_height)
     if strikethrough:
         dl(add_line, strikethrough_position, strikethrough_thickness, cell_height)
 
@@ -384,7 +384,7 @@ def prerender_function(
         render_cursor, cursor_beam_thickness=cursor_beam_thickness,
         cursor_underline_thickness=cursor_underline_thickness, cell_width=cell_width,
         cell_height=cell_height, dpi_x=dpi_x, dpi_y=dpi_y)
-    cells = f(1), f(2), f(3), f(0, True), f(missing=True), c(1), c(2), c(3)
+    cells = f(1), f(2), f(3), f(4), f(5), f(0, True), f(missing=True), c(1), c(2), c(3)
     return tuple(map(ctypes.addressof, cells)), cells
 
 
diff --git a/kitty/shaders.c b/kitty/shaders.c
index f448c8f0d..d99166ff0 100644
--- a/kitty/shaders.c
+++ b/kitty/shaders.c
@@ -314,7 +314,7 @@ cell_update_uniform_block(ssize_t vao_idx, Screen *screen, int uniform_buffer, c
     }
     rd->use_cell_for_selection_bg = IS_SPECIAL_COLOR(highlight_bg) ? 1. : 0.;
     // Cursor position
-    enum { BLOCK_IDX = 0, BEAM_IDX = 6, UNDERLINE_IDX = 7, UNFOCUSED_IDX = 8 };
+    enum { BLOCK_IDX = 0, BEAM_IDX = 8, UNDERLINE_IDX = 9, UNFOCUSED_IDX = 10 };
     if (cursor->is_visible) {
         rd->cursor_x = screen->cursor->x, rd->cursor_y = screen->cursor->y;
         if (cursor->is_focused) {