Handle tab and newline, fix underscore

src/FontAtlas.cake

@@ -11,8 +11,8 @@
   y uint16_t
   width uint16_t
   height uint16_t
-  to-origin-left uint16_t
-  to-origin-top uint16_t
+  to-origin-left int16_t
+  to-origin-top int16_t
   advance-x uint16_t)
 
 (defstruct font-atlas
@@ -28,6 +28,7 @@
 ;; Returns 0 for success or anything else for failure
 (defun build-font-atlas (font-face (* (const (unsigned char)))
                          font-face-size (unsigned int)
+                         character-height-points (unsigned char)
                          font-atlas-out (* font-atlas) &return int)
   (var freetype-library FT_Library)
   (var result int
@@ -47,7 +48,7 @@
   (set result (FT_Set_Char_Size
                typeface    ;; handle to face object
                0       ;; char_width in 1/64th of points
-               (* 16 64)   ;; char_height in 1/64th of points
+               (* character-height-points 64) ;; char_height in 1/64th of points
                300     ;; horizontal device resolution
                300))   ;; vertical device resolution
 

src/Presentation.cake

@@ -31,7 +31,18 @@
                             x int y int str (* (const char)))
   (var write-x int x)
   (var write-y int y)
+  (var tab-width int 100)
+  (var line-height int 100)
   (each-char-in-string-const str current-char
+    (cond
+      ((= (deref current-char) '\n')
+       (set write-y (+ line-height write-y))
+       (set write-x x)
+       (continue))
+      ((= (deref current-char) '\t')
+       (set write-x (+ write-x tab-width))
+       (continue)))
+
     (var search-key char (deref current-char))
     (var glyph (* glyph-entry) (dict-ptr-at (path font > glyph-lookup-table) search-key))
     (unless glyph ;; fallback
@@ -74,8 +85,10 @@
   (defer (SDL_DestroyRenderer renderer))
 
   (var ubuntu-regular-font-atlas font-atlas (array 0))
+  (var font-size-points (unsigned char) 12)
   (unless (= 0 (build-font-atlas s-start-ubuntu-regular-font
                                  (- s-end-ubuntu-regular-font s-start-ubuntu-regular-font)
+                                 font-size-points
                                  (addr ubuntu-regular-font-atlas)))
     (return 1))
   (defer (free-font-atlas (addr ubuntu-regular-font-atlas)))
@@ -127,8 +140,17 @@
        (sdl-print-error)
        (set exit-reason "SDL failed to render font atlas")))
 
-    (render-string renderer (addr ubuntu-regular-font-atlas) ubuntu-regular-texture
-                   200 600 "This is a test!")
+    (render-string
+     renderer (addr ubuntu-regular-font-atlas) ubuntu-regular-texture
+     200 600
+     #"#result= FT_Set_Char_Size(typeface, 0, (16 * 64), 300, 300);
+	if (!((result== FT_Err_Ok)))
+	{
+		fprintf(stderr, "error: encountered error %d while %s\n", result, "setting character size");
+		FT_Done_Face(typeface);
+		FT_Done_FreeType(freetypeLibrary);
+		return 1;
+	}#"#)
 
     (SDL_RenderPresent renderer)
     (SDL_UpdateWindowSurface window)