Merge #9589 from justinmk/cterm-pumblend

UI: 'pumblend' for cterm (256-color TUI)

6 files changed, 130 insertions, 10 deletions

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index f07de55524..4177268780 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -4489,12 +4489,11 @@ A jump table for the options with a short description can be found at |Q_op|.
 						*'pumblend'* *'pb'*
 'pumblend' 'pb'		number	(default 0)
 			global
-	Enables semi-transparency for the completion popupmenu. Valid values
-	are in the range from 0 for fully opaque popupmenu (disabled) to 100
-	for fully transparent background. Lower values 0-30 are typically most
-	useful.
+	Enables pseudo-transparency for the |popup-menu|. Valid values are in
+	the range of 0 for fully opaque popupmenu (disabled) to 100 for fully
+	transparent background. Values between 0-30 are typically most useful.
 
-	UI-dependent. Supported by TUI with 'termguicolors' enabled.
+	UI-dependent. Works best with RGB colors. 'termguicolors'
 
 						*'pyxversion'* *'pyx'*
 'pyxversion' 'pyx'	number	(default depends on the build)
diff --git a/runtime/doc/ui.txt b/runtime/doc/ui.txt
index 84a24ef2a1..77a829b150 100644
--- a/runtime/doc/ui.txt
+++ b/runtime/doc/ui.txt
@@ -160,6 +160,7 @@ the editor.
 	'guifontset'
 	'guifontwide'
 	'linespace'
+	'pumblend'
 	'showtabline'
 	'termguicolors'
 	"ext_*" (all |ui-ext-options|)
diff --git a/runtime/doc/vim_diff.txt b/runtime/doc/vim_diff.txt
index ae0bd2fdb2..25517e506b 100644
--- a/runtime/doc/vim_diff.txt
+++ b/runtime/doc/vim_diff.txt
@@ -189,7 +189,7 @@ Options:
               for |hl-EndOfBuffer| marker
   'inccommand' shows interactive results for |:substitute|-like commands
   'listchars' local to window
-  'pumblend' semi-transparent popupmenu
+  'pumblend' pseudo-transparent popupmenu
   'scrollback'
   'statusline' supports unlimited alignment sections
   'tabline' %@Func@foo%X can call any function on mouse-click
diff --git a/src/nvim/highlight.c b/src/nvim/highlight.c
index ec07f09481..4c5fca6d39 100644
--- a/src/nvim/highlight.c
+++ b/src/nvim/highlight.c
@@ -328,7 +328,8 @@ static HlAttrs get_colors_force(int attr)
 /// Blend overlay attributes (for popupmenu) with other attributes
 ///
 /// This creates a new group when required.
-/// This will be called on a per-cell basis when in use, so cache the result.
+/// This is called per-cell, so cache the result.
+///
 /// @return the resulting attributes.
 int hl_blend_attrs(int back_attr, int front_attr, bool through)
 {
@@ -354,7 +355,8 @@ int hl_blend_attrs(int back_attr, int front_attr, bool through)
     }
 
     cattrs.cterm_bg_color = fattrs.cterm_bg_color;
-    cattrs.cterm_fg_color = fattrs.cterm_bg_color;
+    cattrs.cterm_fg_color = cterm_blend((int)p_pb, battrs.cterm_fg_color,
+                                        fattrs.cterm_bg_color);
   } else {
     cattrs = fattrs;
     if (p_pb >= 50) {
@@ -396,6 +398,86 @@ static int rgb_blend(int ratio, int rgb1, int rgb2)
   return (mr << 16) + (mg << 8) + mb;
 }
 
+static int cterm_blend(int ratio, int c1, int c2)
+{
+  // 1. Convert cterm color numbers to RGB.
+  // 2. Blend the RGB colors.
+  // 3. Convert the RGB result to a cterm color.
+  int rgb1 = hl_cterm2rgb_color(c1);
+  int rgb2 = hl_cterm2rgb_color(c2);
+  int rgb_blended = rgb_blend(ratio, rgb1, rgb2);
+  return hl_rgb2cterm_color(rgb_blended);
+}
+
+/// Converts RGB color to 8-bit color (0-255).
+static int hl_rgb2cterm_color(int rgb)
+{
+  int r = (rgb & 0xFF0000) >> 16;
+  int g = (rgb & 0x00FF00) >> 8;
+  int b = (rgb & 0x0000FF) >> 0;
+
+  return (r * 6 / 256) * 36 + (g * 6 / 256) * 6 + (b * 6 / 256);
+}
+
+/// Converts 8-bit color (0-255) to RGB color.
+/// This is compatible with xterm.
+static int hl_cterm2rgb_color(int nr)
+{
+  static int cube_value[] = {
+    0x00, 0x5F, 0x87, 0xAF, 0xD7, 0xFF
+  };
+  static int grey_ramp[] = {
+    0x08, 0x12, 0x1C, 0x26, 0x30, 0x3A, 0x44, 0x4E, 0x58, 0x62, 0x6C, 0x76,
+    0x80, 0x8A, 0x94, 0x9E, 0xA8, 0xB2, 0xBC, 0xC6, 0xD0, 0xDA, 0xE4, 0xEE
+  };
+  static char_u ansi_table[16][4] = {
+    //  R    G    B   idx
+    {   0,   0,   0,  1 } ,  // black
+    { 224,   0,   0,  2 } ,  // dark red
+    {   0, 224,   0,  3 } ,  // dark green
+    { 224, 224,   0,  4 } ,  // dark yellow / brown
+    {   0,   0, 224,  5 } ,  // dark blue
+    { 224,   0, 224,  6 } ,  // dark magenta
+    {   0, 224, 224,  7 } ,  // dark cyan
+    { 224, 224, 224,  8 } ,  // light grey
+
+    { 128, 128, 128,  9 } ,  // dark grey
+    { 255,  64,  64, 10 } ,  // light red
+    {  64, 255,  64, 11 } ,  // light green
+    { 255, 255,  64, 12 } ,  // yellow
+    {  64,  64, 255, 13 } ,  // light blue
+    { 255,  64, 255, 14 } ,  // light magenta
+    {  64, 255, 255, 15 } ,  // light cyan
+    { 255, 255, 255, 16 } ,  // white
+  };
+
+  int r = 0;
+  int g = 0;
+  int b = 0;
+  int idx;
+  // *ansi_idx = 0;
+
+  if (nr < 16) {
+    r = ansi_table[nr][0];
+    g = ansi_table[nr][1];
+    b = ansi_table[nr][2];
+    // *ansi_idx = ansi_table[nr][3];
+  } else if (nr < 232) {  // 216 color-cube
+    idx = nr - 16;
+    r = cube_value[idx / 36 % 6];
+    g = cube_value[idx / 6  % 6];
+    b = cube_value[idx      % 6];
+    // *ansi_idx = -1;
+  } else if (nr < 256) {  // 24 greyscale ramp
+    idx = nr - 232;
+    r = grey_ramp[idx];
+    g = grey_ramp[idx];
+    b = grey_ramp[idx];
+    // *ansi_idx = -1;
+  }
+  return (r << 16) + (g << 8) + b;
+}
+
 /// Get highlight attributes for a attribute code
 HlAttrs syn_attr2entry(int attr)
 {
diff --git a/src/nvim/ui_compositor.c b/src/nvim/ui_compositor.c
index 59ae9c34ec..c7ba0306e4 100644
--- a/src/nvim/ui_compositor.c
+++ b/src/nvim/ui_compositor.c
@@ -259,9 +259,10 @@ static void compose_line(Integer row, Integer startcol, Integer endcol,
     memcpy(linebuf+(col-startcol), grid->chars+off, n * sizeof(*linebuf));
     memcpy(attrbuf+(col-startcol), grid->attrs+off, n * sizeof(*attrbuf));
 
+    // 'pumblend'
     if (grid != &default_grid && p_pb) {
       for (int i = col-(int)startcol; i < until-startcol; i++) {
-        bool thru = strequal((char *)linebuf[i], " ");
+        bool thru = strequal((char *)linebuf[i], " ");  // negative space
         attrbuf[i] = (sattr_T)hl_blend_attrs(bg_attrs[i], attrbuf[i], thru);
         if (thru) {
           memcpy(linebuf[i], bg_line[i], sizeof(linebuf[i]));
diff --git a/test/functional/ui/popupmenu_spec.lua b/test/functional/ui/popupmenu_spec.lua
index 62428c9657..9a8c5a5789 100644
--- a/test/functional/ui/popupmenu_spec.lua
+++ b/test/functional/ui/popupmenu_spec.lua
@@ -1273,7 +1273,7 @@ describe('builtin popupmenu', function()
     ]])
   end)
 
-  it('works with pumblend', function()
+  it("'pumblend' RGB-color", function()
     screen:try_resize(60,14)
     screen:set_default_attr_ids({
       [1] = {background = Screen.colors.Yellow},
@@ -1448,4 +1448,41 @@ describe('builtin popupmenu', function()
       {20:-- INSERT --}                                                |
     ]])
   end)
+
+  it("'pumblend' 256-color (non-RGB)", function()
+    screen:detach()
+    screen = Screen.new(60, 8)
+    screen:attach({rgb=false, ext_popupmenu=false})
+    screen:set_default_attr_ids({
+      [1] = {foreground = Screen.colors.Grey0, background = tonumber('0x000007')},
+      [2] = {foreground = tonumber('0x000055'), background = tonumber('0x000007')},
+      [3] = {foreground = tonumber('0x00008f'), background = Screen.colors.Grey0},
+      [4] = {foreground = Screen.colors.Grey0, background = tonumber('0x0000e1')},
+      [5] = {foreground = tonumber('0x0000d1'), background = tonumber('0x0000e1')},
+      [6] = {foreground = Screen.colors.NavyBlue, background = tonumber('0x0000f8')},
+      [7] = {foreground = tonumber('0x0000a5'), background = tonumber('0x0000f8')},
+      [8] = {foreground = tonumber('0x00000c')},
+      [9] = {bold = true},
+      [10] = {foreground = tonumber('0x000002')},
+    })
+    command('set notermguicolors pumblend=10')
+    insert([[
+      Lorem ipsum dolor sit amet, consectetur
+      adipisicing elit, sed do eiusmod tempor
+      incididunt ut labore et dolore magna aliqua.
+      Ut enim ad minim veniam, quis nostrud
+      laborum.]])
+
+    feed('ggOdo<c-x><c-n>')
+    screen:expect([[
+      dolor^                                                       |
+      {1:dolor}{2: ipsum dol}or sit amet, consectetur                     |
+      {4:do}{5:ipisicing eli}t, sed do eiusmod tempor                     |
+      {4:dolore}{5:dunt ut l}abore et dolore magna aliqua.                |
+      Ut enim ad minim veniam, quis nostrud                       |
+      laborum.                                                    |
+      {8:~                                                           }|
+      {9:-- Keyword Local completion (^N^P) }{10:match 1 of 3}             |
+    ]])
+  end)
 end)