text: Batch glyphs into one wish -- fixes performance.

1 files changed, 6 insertions, 1 deletions

diff --git a/virtual-programs/display/text.folk b/virtual-programs/display/text.folk
index 992e77b1..a6c828b9 100644
--- a/virtual-programs/display/text.folk
+++ b/virtual-programs/display/text.folk
@@ -124,6 +124,7 @@ On process "display" {
         set x $x0; set y $y0
 
         set lineNum 0
+        set instances [list]
         for {set i 0} {$i < [string length $text]} {incr i} {
             set char [string index $text $i]
             if {$char eq "\n"} {
@@ -140,12 +141,16 @@ On process "display" {
             }
             lassign $glyphInfo advance planeBounds atlasBounds
             if {$char ne " "} {
-                Wish the GPU draws pipeline "glyph" with arguments \
+                lappend instances \
                     [list $fontAtlas $fontAtlasSize \
                          $atlasBounds $planeBounds [list $x $y] $radians $em]
             }
             lassign [vec2 add [list $x $y] \
                          [vec2 rotate [list [* $advance $em] 0] $radians]] x y
         }
+
+        # We need to batch into one wish so we don't deal with n^2
+        # checks for existing statements for n glyphs.
+        Wish the GPU draws pipeline "glyph" with instances $instances
     }
 }