Add font loader

sys/BUILD

@@ -1,7 +1,22 @@
+load("@bazel_skylib//rules:run_binary.bzl", "run_binary")
+
 cc_library(
     name = "sys",
-    srcs = glob(["*.c"]),
-    hdrs = glob(["*.h"]),
+    srcs = glob(["*.c"]) + [":fonts/sys_font_small.c"],
+    hdrs = glob(["*.h"]) + [":fonts/sys_font_small.h"],
     visibility = ["//visibility:public"],
-    deps = ["//device:device"]
+    deps = ["//device:device"],
+)
+
+run_binary(
+    name = "sys_font_small",
+    args = [
+        "sys_font_small",
+        "256",
+        "$(location :fonts/sys_font_small.png)", 
+        "$(location :fonts/sys_font_small.c)"
+    ],
+    srcs = [":fonts/sys_font_small.png"],
+    outs = [":fonts/sys_font_small.c"],
+    tool = "//pytools:font",
 )

sys/fonts/sys_font_small.h

@@ -0,0 +1,8 @@
+#ifndef CROCPARTY_SYS_FONT_SMALL_H
+#define CROCPARTY_SYS_FONT_SMALL_H
+
+#include "sys/sys.h"
+
+extern sys_glyph sys_font_small[256];
+
+#endif  // CROCPARTY_SYS_FONT_SMALL_H

sys/sys.h

@@ -3,6 +3,7 @@
 
 #include "sys_data.h"
 #include "sys_graphics.h"
+#include "fonts/sys_font_small.h"
 
 /**
  * Initialize sys. 

sys/sys_data.h

@@ -6,6 +6,7 @@
 typedef int32_t sys_i32;
 typedef uint8_t sys_color;
 typedef uint32_t sys_screen_color;
+typedef uint64_t sys_glyph;
 
 sys_screen_color sys_make_screen_color(uint8_t r, uint8_t g, uint8_t b);
 

sys/sys_graphics.c

@@ -11,6 +11,7 @@ void sys_pixel_internal_set(sys_i32 x, sys_i32 y, sys_color c);
 void sys_scanline_internal_set(
     sys_i32 x0, sys_i32 x1, sys_i32 y, sys_color c, bool fill
 );
+void sys_glyph_draw(sys_i32 x, sys_i32 y, sys_glyph g, sys_color c);
 
 // == public ==
 void sys_clip_set(sys_i32 x0, sys_i32 y0, sys_i32 x1, sys_i32 y1) {
@@ -55,6 +56,18 @@ sys_color sys_pixel_get(sys_i32 x, sys_i32 y) {
     return device_pixels[y][x];
 }
 
+void sys_print(char* str, sys_i32 x, sys_i32 y, sys_color col) {
+    sys_i32 x_orig = x;
+    for (sys_i32 i = 0;; i++) {
+        uint8_t c = str[i];
+        if (c == 0) { break; }
+        if (c == '\n') { x = x_orig; y += 8; continue; }
+        if (c == '\r') { x = x_orig; continue; }
+        sys_glyph_draw(x, y, sys_font_small[c], col);
+        x += 8;
+    }
+}
+
 void sys_cls(sys_color c) {
     assert(sys_get_initialized());
 
@@ -250,4 +263,17 @@ void sys_scanline_internal_set(
         sys_pixel_internal_set(x0, y, c);
         sys_pixel_internal_set(x1, y, c);
     }
+}
+
+void sys_glyph_draw(sys_i32 x, sys_i32 y, sys_glyph g, sys_color c) {
+    // iterate through the bits of the glyph, and draw the character
+    // if that bit is set
+    for (int py = 0; py < 8; py++) {
+        for (int px = 0; px < 8; px++) {
+            uint64_t mask = ((uint64_t) 1) << (uint64_t) (py * 8 + px);
+            if ((g & mask) != 0) {
+                sys_pixel_internal_set(x + px, y + py, c);
+            }
+        }
+    }
 }

sys/sys_graphics.h

@@ -54,7 +54,10 @@ sys_color sys_pixel_get(
 
 // TODO: SSET/SGET
 // TODO: FGET/FSET
-// TODO: PRINT
+/**
+ * Print a string `str` in the color `col`
+ */
+void sys_print(char* str, sys_i32 x, sys_i32 y, sys_color col);
 // TODO: CURSOR? COLOR?
 
 /**
@@ -83,7 +86,7 @@ void sys_camera_reset();
  * This is a special case of sys_circ_oval_draw_ext.
  */
 void sys_circ_draw(sys_i32 x, sys_i32 y, sys_i32 r, sys_color c);  
-void sys_circ_fill(sys_i32 x, sys_i32 y, sys_i32 r);  
+void sys_circ_fill(sys_i32 x, sys_i32 y, sys_i32 r, sys_color c);  
 void sys_circ_draw_ext(sys_i32 x, sys_i32 y, sys_i32 r, sys_color c, bool fill);
 
 /**