fix linking with allegro primitives, fix header name when installed, update readme

CMakeLists.txt

@@ -3,7 +3,7 @@ include_directories(../font)
 
 set(TTF_SOURCES allegro_schrift.c schrift.c)
 
-set(TTF_INCLUDE_FILES allegro5/allegro_schrift.h)
+set(TTF_INCLUDE_FILES allegro5/allegro_ttf.h)
 
 #set_our_header_properties(${TTF_INCLUDE_FILES})
 
@@ -16,7 +16,7 @@ add_our_addon_library(allegro_ttf
     AllegroTTF-${ALLEGRO_SOVERSION}
     "${TTF_SOURCES};${TTF_INCLUDE_FILES}"
     "-DALLEGRO_TTF_SRC"
-    "${FONT_LINK_WITH};${TTF_LIBRARIES}"
+    "${FONT_LINK_WITH};${PRIMITIVES_LINK_WITH};${TTF_LIBRARIES}"
     )
 
 #target_compile_options(allegro_ttf PRIVATE "-fsanitize=undefined" "-lasan")

README.md

@@ -3,19 +3,27 @@ Drop-in replacement for Allegro_TTF that contains libschrift, instead of using F
 
 It is 100% API compatible with the vanilla TrueType addon. Compile Allegro with these files inside of `/addons/ttf`.
 
+Requires the primitives addon.
+
 ![Comparison between FreeType2 and schrift when running Allegro's ex_ttf demo](comparison.png)
 
-Pros:
+## Pros
 - It doesn't require NT 6 kernel calls
 - It doesn't dynamically link against hundreds of thousands of lines of ugly corporate-backed C code you can't read
   - Our addon is only a couple or few hundred lines, and libschrift is less than 2,000. They're compiled together.  
   The original Allegro_TTF is over 1,000 lines (for a good reason) and has a relatively massive dependency weight (for a stupid reason).
 
-Caveats:
+## Caveats
 - Pre-stretching is not implemented.
-- The entire caching system is gone, fonts are baked to textures immediately and no further. This makes supporting some languages with this add-on inconvenient, or impossible.  
-If your usecase doesn't need every fancy rendering feature and can use schrift, you probably aren't supporting enough characters and languages to need on-the-fly caching, so we consider this an acceptable tradeoff.
+- The entire caching system is gone, fonts are baked to textures immediately and no further. This makes supporting some languages with this add-on inconvenient, and increases load times. For many users this an acceptable tradeoff.
     - The `cache_text` setting in allegro5.cfg is now reused to determine what glyphs can be rendered at all. `skip_cache_misses` has no effect.  
     When `cache_text` is undefined, the [Latin](https://en.wikipedia.org/wiki/ASCII), [Germanic, and Romance](https://en.wikipedia.org/wiki/Latin_Extended-A) alphabets will be generated by default. (not necessarily 32 - 255)
     - **TODO** Alternatively, the developer can force a custom range of unicode characters to be generated using a new parameter in the `al_load_ttf_font` function.
 - Kerning, per-character advance and offsets, and other features which are exposed by libschrift are not currently implemented, but doing so is possible. See the above comparison screenshot.
+
+## In Practice
+You can see here some of the flaws with this implementation. Line heights are taller than they should be, and there's an issue with string endings or other characters.  
+
+Not visible in the below example is the atlas size to hold glyph data.  
+
+![Time Falcon main menu with the allegro_schrift plugin, work in progress](schrift_demo_wip.png)

allegro5/allegro_ttf.h

@@ -1,3 +1,5 @@
+// this header needs to be named allegro_ttf.h so it replaces the FreeType header
+
 #ifndef __al_included_allegro5_allegro_ttf_h
 #define __al_included_allegro5_allegro_ttf_h
 

allegro_schrift.c

@@ -4,7 +4,7 @@
 #include "allegro5/internal/aintern.h"
 #include "allegro5/internal/aintern_vector.h"
 
-#include "allegro5/allegro_schrift.h"
+#include "allegro5/allegro_ttf.h"
 #include "allegro5/internal/aintern_font.h"
 #include "allegro5/internal/aintern_dtor.h"
 #include "allegro5/internal/aintern_system.h"
@@ -48,6 +48,11 @@ ALLEGRO_BITMAP *grow_bitmap(ALLEGRO_BITMAP *bmp, uint16_t add) {
 ALLEGRO_FONT *al_load_ttf_font_f(ALLEGRO_FILE *file,
     char const *filename, int size, int flags)
 {
+		if (!al_is_primitives_addon_initialized() && !al_init_primitives_addon()) {
+			ALLEGRO_ERROR("Can't load font %s: primitives couldn't be set up\n", filename);
+			return NULL;
+		}
+
 		#define CLEANUP free(filebuf); if (gtex) al_destroy_bitmap(gtex); al_set_target_bitmap(tgt)
 		#define FAIL CLEANUP; return NULL