Don't request a highlight colour in games that don't need one

This means that Range, Singles, and Tracks can now use the default
background colour even if it's close to white.  In the case of Singles
I've left a dummy entry in the colour list so as not to renumber the
rest and break everyone's environment variables.  If Singles ever needs
a new colour it can re-use that slot.

3 files changed, 6 insertions, 7 deletions

diff --git a/range.c b/range.c
index 103c136..d6d17eb 100644
--- a/range.c
+++ b/range.c
@@ -1624,7 +1624,6 @@ enum {
     COL_USER = COL_GRID,
     COL_ERROR,
     COL_LOWLIGHT,
-    COL_HIGHLIGHT = COL_ERROR, /* mkhighlight needs it, I don't */
     COL_CURSOR = COL_LOWLIGHT,
     NCOLOURS
 };
@@ -1649,7 +1648,7 @@ static float *game_colours(frontend *fe, int *ncolours)
 {
     float *ret = snewn(3 * NCOLOURS, float);
 
-    game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
+    game_mkhighlight(fe, ret, COL_BACKGROUND, -1, COL_LOWLIGHT);
     COLOUR(ret, COL_GRID,  0.0F, 0.0F, 0.0F);
     COLOUR(ret, COL_ERROR, 1.0F, 0.0F, 0.0F);
 
diff --git a/singles.c b/singles.c
index 6c35162..42ecdbe 100644
--- a/singles.c
+++ b/singles.c
@@ -82,7 +82,7 @@ bool verbose = false;
 #define FLASH_TIME 0.7F
 
 enum {
-    COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT,
+    COL_BACKGROUND, COL_UNUSED1, COL_LOWLIGHT,
     COL_BLACK, COL_WHITE, COL_BLACKNUM, COL_GRID,
     COL_CURSOR, COL_ERROR,
     NCOLOURS
@@ -1620,12 +1620,13 @@ static float *game_colours(frontend *fe, int *ncolours)
     float *ret = snewn(3 * NCOLOURS, float);
     int i;
 
-    game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
+    game_mkhighlight(fe, ret, COL_BACKGROUND, -1, COL_LOWLIGHT);
     for (i = 0; i < 3; i++) {
         ret[COL_BLACK * 3 + i] = 0.0F;
         ret[COL_BLACKNUM * 3 + i] = 0.4F;
         ret[COL_WHITE * 3 + i] = 1.0F;
         ret[COL_GRID * 3 + i] = ret[COL_LOWLIGHT * 3 + i];
+        ret[COL_UNUSED1 * 3 + i] = 0.0F; /* To placate an assertion. */
     }
     ret[COL_CURSOR * 3 + 0] = 0.2F;
     ret[COL_CURSOR * 3 + 1] = 0.8F;
diff --git a/tracks.c b/tracks.c
index 9b5ef4c..afb9ff9 100644
--- a/tracks.c
+++ b/tracks.c
@@ -2463,8 +2463,7 @@ static void game_set_size(drawing *dr, game_drawstate *ds,
 }
 
 enum {
-    COL_BACKGROUND, COL_LOWLIGHT, COL_HIGHLIGHT,
-    COL_TRACK_BACKGROUND = COL_LOWLIGHT,
+    COL_BACKGROUND, COL_TRACK_BACKGROUND,
     COL_GRID, COL_CLUE, COL_CURSOR,
     COL_TRACK, COL_TRACK_CLUE, COL_SLEEPER,
     COL_DRAGON, COL_DRAGOFF,
@@ -2477,7 +2476,7 @@ static float *game_colours(frontend *fe, int *ncolours)
     float *ret = snewn(3 * NCOLOURS, float);
     int i;
 
-    game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
+    game_mkhighlight(fe, ret, COL_BACKGROUND, -1, COL_TRACK_BACKGROUND);
 
     for (i = 0; i < 3; i++) {
         ret[COL_TRACK_CLUE       * 3 + i] = 0.0F;