Draw the TUI's cells as pixels with the symbols' glyphs

vega pixels runs the same scripts as tui --dump and writes each frame as
an image: the view's cells (only those on screen are evaluated) become
glyphs, each drawn once per size with the exact area of its curves, in its
tone's colour on its row's background. No page, no scene in between. A
1920x1350 grid takes 12 ms a frame here, writing the image included.

Symbol files carry the font's line now (format 3: ascent and descent where
format 2 kept zeros), the cell height and baseline; and the build tool takes
fonts in order, later ones filling the codes earlier ones lack: a CJK font
alone drew ambiguous-width arrows two cells wide in a one-cell grid, which
the new check caught, so a monospace Latin font comes first and Hangul after.

1 files changed, 1 insertions, 6 deletions

diff --git a/symbols/symbols-gl.h b/symbols/symbols-gl.h
index 919a114..cc316a4 100644
--- a/symbols/symbols-gl.h
+++ b/symbols/symbols-gl.h
@@ -14,17 +14,12 @@ typedef struct {
     GLint target;
 } VegaGl;
 
-/* Where each symbol is in an atlas: its rectangle there (x, y, width, height)
- * and the pixel offset of that rectangle's top left from the symbol's origin
- * (right, up). A symbol with nothing to draw has an empty rectangle. */
-typedef struct { int32_t x, y, width, height, left, top; } VegaPlace;
-
 typedef struct {
     GLuint texture; /* 8-bit coverage */
     int width, height;
     float scale;    /* pixels per unit */
     uint32_t symbols;
-    VegaPlace *places; /* per symbol index */
+    VegaPlace *places; /* per symbol index: its box and where the atlas keeps it */
 } VegaAtlas;
 
 /* A symbol at a pen position (whole pixels from the target's top left, on the