show tile numbers

5 files changed, 311 insertions, 0 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 22f140bfac..4db400e113 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,4 +1,5 @@
 SET(llmr_SOURCES
+    geometry/debug_font_buffer.cpp
     geometry/linevertexbuffer.cpp
     map/map.cpp
     map/tile.cpp
@@ -12,6 +13,7 @@ SET(llmr_SOURCES
 )
 
 SET(llmr_HEADERS
+    ../include/llmr/geometry/debug_font_buffer.hpp
     ../include/llmr/geometry/linevertexbuffer.hpp
     ../include/llmr/llmr.hpp
     ../include/llmr/map/map.hpp
diff --git a/src/geometry/debug_font_buffer.cpp b/src/geometry/debug_font_buffer.cpp
new file mode 100644
index 0000000000..57ebceb263
--- /dev/null
+++ b/src/geometry/debug_font_buffer.cpp
@@ -0,0 +1,279 @@
+#include <llmr/geometry/debug_font_buffer.hpp>
+#include <llmr/platform/gl.hpp>
+
+#include <cmath>
+
+int8_t simplex_0[] = { };
+int8_t simplex_1[] = { 5, 21, 5, 7, -1, -1, 5, 2, 4, 1, 5, 0, 6, 1, 5, 2 };
+int8_t simplex_2[] = { 4, 21, 4, 14, -1, -1, 12, 21, 12, 14 };
+int8_t simplex_3[] = { 11, 25, 4, -7, -1, -1, 17, 25, 10, -7, -1, -1, 4, 12, 18, 12, -1, -1, 3, 6, 17, 6 };
+int8_t simplex_4[] = { 8, 25, 8, -4, -1, -1, 12, 25, 12, -4, -1, -1, 17, 18, 15, 20, 12, 21, 8, 21, 5, 20, 3, 18, 3, 16, 4, 14, 5, 13, 7, 12, 13, 10, 15, 9, 16, 8, 17, 6, 17, 3, 15, 1, 12, 0, 8, 0, 5, 1, 3, 3 };
+int8_t simplex_5[] = { 21, 21, 3, 0, -1, -1, 8, 21, 10, 19, 10, 17, 9, 15, 7, 14, 5, 14, 3, 16, 3, 18, 4, 20, 6, 21, 8, 21, 10, 20, 13, 19, 16, 19, 19, 20, 21, 21, -1, -1, 17, 7, 15, 6, 14, 4, 14, 2, 16, 0, 18, 0, 20, 1, 21, 3, 21, 5, 19, 7, 17, 7 };
+int8_t simplex_6[] = { 23, 12, 23, 13, 22, 14, 21, 14, 20, 13, 19, 11, 17, 6, 15, 3, 13, 1, 11, 0, 7, 0, 5, 1, 4, 2, 3, 4, 3, 6, 4, 8, 5, 9, 12, 13, 13, 14, 14, 16, 14, 18, 13, 20, 11, 21, 9, 20, 8, 18, 8, 16, 9, 13, 11, 10, 16, 3, 18, 1, 20, 0, 22, 0, 23, 1, 23, 2 };
+int8_t simplex_7[] = { 5, 19, 4, 20, 5, 21, 6, 20, 6, 18, 5, 16, 4, 15 };
+int8_t simplex_8[] = { 11, 25, 9, 23, 7, 20, 5, 16, 4, 11, 4, 7, 5, 2, 7, -2, 9, -5, 11, -7 };
+int8_t simplex_9[] = { 3, 25, 5, 23, 7, 20, 9, 16, 10, 11, 10, 7, 9, 2, 7, -2, 5, -5, 3, -7 };
+int8_t simplex_10[] = { 8, 21, 8, 9, -1, -1, 3, 18, 13, 12, -1, -1, 13, 18, 3, 12 };
+int8_t simplex_11[] = { 13, 18, 13, 0, -1, -1, 4, 9, 22, 9 };
+int8_t simplex_12[] = { 6, 1, 5, 0, 4, 1, 5, 2, 6, 1, 6, -1, 5, -3, 4, -4 };
+int8_t simplex_13[] = { 4, 9, 22, 9 };
+int8_t simplex_14[] = { 5, 2, 4, 1, 5, 0, 6, 1, 5, 2 };
+int8_t simplex_15[] = { 20, 25, 2, -7 };
+int8_t simplex_16[] = { 9, 21, 6, 20, 4, 17, 3, 12, 3, 9, 4, 4, 6, 1, 9, 0, 11, 0, 14, 1, 16, 4, 17, 9, 17, 12, 16, 17, 14, 20, 11, 21, 9, 21 };
+int8_t simplex_17[] = { 6, 17, 8, 18, 11, 21, 11, 0 };
+int8_t simplex_18[] = { 4, 16, 4, 17, 5, 19, 6, 20, 8, 21, 12, 21, 14, 20, 15, 19, 16, 17, 16, 15, 15, 13, 13, 10, 3, 0, 17, 0 };
+int8_t simplex_19[] = { 5, 21, 16, 21, 10, 13, 13, 13, 15, 12, 16, 11, 17, 8, 17, 6, 16, 3, 14, 1, 11, 0, 8, 0, 5, 1, 4, 2, 3, 4 };
+int8_t simplex_20[] = { 13, 21, 3, 7, 18, 7, -1, -1, 13, 21, 13, 0 };
+int8_t simplex_21[] = { 15, 21, 5, 21, 4, 12, 5, 13, 8, 14, 11, 14, 14, 13, 16, 11, 17, 8, 17, 6, 16, 3, 14, 1, 11, 0, 8, 0, 5, 1, 4, 2, 3, 4 };
+int8_t simplex_22[] = { 16, 18, 15, 20, 12, 21, 10, 21, 7, 20, 5, 17, 4, 12, 4, 7, 5, 3, 7, 1, 10, 0, 11, 0, 14, 1, 16, 3, 17, 6, 17, 7, 16, 10, 14, 12, 11, 13, 10, 13, 7, 12, 5, 10, 4, 7 };
+int8_t simplex_23[] = { 17, 21, 7, 0, -1, -1, 3, 21, 17, 21 };
+int8_t simplex_24[] = { 8, 21, 5, 20, 4, 18, 4, 16, 5, 14, 7, 13, 11, 12, 14, 11, 16, 9, 17, 7, 17, 4, 16, 2, 15, 1, 12, 0, 8, 0, 5, 1, 4, 2, 3, 4, 3, 7, 4, 9, 6, 11, 9, 12, 13, 13, 15, 14, 16, 16, 16, 18, 15, 20, 12, 21, 8, 21 };
+int8_t simplex_25[] = { 16, 14, 15, 11, 13, 9, 10, 8, 9, 8, 6, 9, 4, 11, 3, 14, 3, 15, 4, 18, 6, 20, 9, 21, 10, 21, 13, 20, 15, 18, 16, 14, 16, 9, 15, 4, 13, 1, 10, 0, 8, 0, 5, 1, 4, 3 };
+int8_t simplex_26[] = { 5, 14, 4, 13, 5, 12, 6, 13, 5, 14, -1, -1, 5, 2, 4, 1, 5, 0, 6, 1, 5, 2 };
+int8_t simplex_27[] = { 5, 14, 4, 13, 5, 12, 6, 13, 5, 14, -1, -1, 6, 1, 5, 0, 4, 1, 5, 2, 6, 1, 6, -1, 5, -3, 4, -4 };
+int8_t simplex_28[] = { 20, 18, 4, 9, 20, 0 };
+int8_t simplex_29[] = { 4, 12, 22, 12, -1, -1, 4, 6, 22, 6 };
+int8_t simplex_30[] = { 4, 18, 20, 9, 4, 0 };
+int8_t simplex_31[] = { 3, 16, 3, 17, 4, 19, 5, 20, 7, 21, 11, 21, 13, 20, 14, 19, 15, 17, 15, 15, 14, 13, 13, 12, 9, 10, 9, 7, -1, -1, 9, 2, 8, 1, 9, 0, 10, 1, 9, 2 };
+int8_t simplex_32[] = { 18, 13, 17, 15, 15, 16, 12, 16, 10, 15, 9, 14, 8, 11, 8, 8, 9, 6, 11, 5, 14, 5, 16, 6, 17, 8, -1, -1, 12, 16, 10, 14, 9, 11, 9, 8, 10, 6, 11, 5, -1, -1, 18, 16, 17, 8, 17, 6, 19, 5, 21, 5, 23, 7, 24, 10, 24, 12, 23, 15, 22, 17, 20, 19, 18, 20, 15, 21, 12, 21, 9, 20, 7, 19, 5, 17, 4, 15, 3, 12, 3, 9, 4, 6, 5, 4, 7, 2, 9, 1, 12, 0, 15, 0, 18, 1, 20, 2, 21, 3, -1, -1, 19, 16, 18, 8, 18, 6, 19, 5 };
+int8_t simplex_33[] = { 9, 21, 1, 0, -1, -1, 9, 21, 17, 0, -1, -1, 4, 7, 14, 7 };
+int8_t simplex_34[] = { 4, 21, 4, 0, -1, -1, 4, 21, 13, 21, 16, 20, 17, 19, 18, 17, 18, 15, 17, 13, 16, 12, 13, 11, -1, -1, 4, 11, 13, 11, 16, 10, 17, 9, 18, 7, 18, 4, 17, 2, 16, 1, 13, 0, 4, 0 };
+int8_t simplex_35[] = { 18, 16, 17, 18, 15, 20, 13, 21, 9, 21, 7, 20, 5, 18, 4, 16, 3, 13, 3, 8, 4, 5, 5, 3, 7, 1, 9, 0, 13, 0, 15, 1, 17, 3, 18, 5 };
+int8_t simplex_36[] = { 4, 21, 4, 0, -1, -1, 4, 21, 11, 21, 14, 20, 16, 18, 17, 16, 18, 13, 18, 8, 17, 5, 16, 3, 14, 1, 11, 0, 4, 0 };
+int8_t simplex_37[] = { 4, 21, 4, 0, -1, -1, 4, 21, 17, 21, -1, -1, 4, 11, 12, 11, -1, -1, 4, 0, 17, 0 };
+int8_t simplex_38[] = { 4, 21, 4, 0, -1, -1, 4, 21, 17, 21, -1, -1, 4, 11, 12, 11 };
+int8_t simplex_39[] = { 18, 16, 17, 18, 15, 20, 13, 21, 9, 21, 7, 20, 5, 18, 4, 16, 3, 13, 3, 8, 4, 5, 5, 3, 7, 1, 9, 0, 13, 0, 15, 1, 17, 3, 18, 5, 18, 8, -1, -1, 13, 8, 18, 8 };
+int8_t simplex_40[] = { 4, 21, 4, 0, -1, -1, 18, 21, 18, 0, -1, -1, 4, 11, 18, 11 };
+int8_t simplex_41[] = { 4, 21, 4, 0 };
+int8_t simplex_42[] = { 12, 21, 12, 5, 11, 2, 10, 1, 8, 0, 6, 0, 4, 1, 3, 2, 2, 5, 2, 7 };
+int8_t simplex_43[] = { 4, 21, 4, 0, -1, -1, 18, 21, 4, 7, -1, -1, 9, 12, 18, 0 };
+int8_t simplex_44[] = { 4, 21, 4, 0, -1, -1, 4, 0, 16, 0 };
+int8_t simplex_45[] = { 4, 21, 4, 0, -1, -1, 4, 21, 12, 0, -1, -1, 20, 21, 12, 0, -1, -1, 20, 21, 20, 0 };
+int8_t simplex_46[] = { 4, 21, 4, 0, -1, -1, 4, 21, 18, 0, -1, -1, 18, 21, 18, 0 };
+int8_t simplex_47[] = { 9, 21, 7, 20, 5, 18, 4, 16, 3, 13, 3, 8, 4, 5, 5, 3, 7, 1, 9, 0, 13, 0, 15, 1, 17, 3, 18, 5, 19, 8, 19, 13, 18, 16, 17, 18, 15, 20, 13, 21, 9, 21 };
+int8_t simplex_48[] = { 4, 21, 4, 0, -1, -1, 4, 21, 13, 21, 16, 20, 17, 19, 18, 17, 18, 14, 17, 12, 16, 11, 13, 10, 4, 10 };
+int8_t simplex_49[] = { 9, 21, 7, 20, 5, 18, 4, 16, 3, 13, 3, 8, 4, 5, 5, 3, 7, 1, 9, 0, 13, 0, 15, 1, 17, 3, 18, 5, 19, 8, 19, 13, 18, 16, 17, 18, 15, 20, 13, 21, 9, 21, -1, -1, 12, 4, 18, -2 };
+int8_t simplex_50[] = { 4, 21, 4, 0, -1, -1, 4, 21, 13, 21, 16, 20, 17, 19, 18, 17, 18, 15, 17, 13, 16, 12, 13, 11, 4, 11, -1, -1, 11, 11, 18, 0 };
+int8_t simplex_51[] = { 17, 18, 15, 20, 12, 21, 8, 21, 5, 20, 3, 18, 3, 16, 4, 14, 5, 13, 7, 12, 13, 10, 15, 9, 16, 8, 17, 6, 17, 3, 15, 1, 12, 0, 8, 0, 5, 1, 3, 3 };
+int8_t simplex_52[] = { 8, 21, 8, 0, -1, -1, 1, 21, 15, 21 };
+int8_t simplex_53[] = { 4, 21, 4, 6, 5, 3, 7, 1, 10, 0, 12, 0, 15, 1, 17, 3, 18, 6, 18, 21 };
+int8_t simplex_54[] = { 1, 21, 9, 0, -1, -1, 17, 21, 9, 0 };
+int8_t simplex_55[] = { 2, 21, 7, 0, -1, -1, 12, 21, 7, 0, -1, -1, 12, 21, 17, 0, -1, -1, 22, 21, 17, 0 };
+int8_t simplex_56[] = { 3, 21, 17, 0, -1, -1, 17, 21, 3, 0 };
+int8_t simplex_57[] = { 1, 21, 9, 11, 9, 0, -1, -1, 17, 21, 9, 11 };
+int8_t simplex_58[] = { 17, 21, 3, 0, -1, -1, 3, 21, 17, 21, -1, -1, 3, 0, 17, 0 };
+int8_t simplex_59[] = { 4, 25, 4, -7, -1, -1, 5, 25, 5, -7, -1, -1, 4, 25, 11, 25, -1, -1, 4, -7, 11, -7 };
+int8_t simplex_60[] = { 0, 21, 14, -3 };
+int8_t simplex_61[] = { 9, 25, 9, -7, -1, -1, 10, 25, 10, -7, -1, -1, 3, 25, 10, 25, -1, -1, 3, -7, 10, -7 };
+int8_t simplex_62[] = { 6, 15, 8, 18, 10, 15, -1, -1, 3, 12, 8, 17, 13, 12, -1, -1, 8, 17, 8, 0 };
+int8_t simplex_63[] = { 0, -2, 16, -2 };
+int8_t simplex_64[] = { 6, 21, 5, 20, 4, 18, 4, 16, 5, 15, 6, 16, 5, 17 };
+int8_t simplex_65[] = { 15, 14, 15, 0, -1, -1, 15, 11, 13, 13, 11, 14, 8, 14, 6, 13, 4, 11, 3, 8, 3, 6, 4, 3, 6, 1, 8, 0, 11, 0, 13, 1, 15, 3 };
+int8_t simplex_66[] = { 4, 21, 4, 0, -1, -1, 4, 11, 6, 13, 8, 14, 11, 14, 13, 13, 15, 11, 16, 8, 16, 6, 15, 3, 13, 1, 11, 0, 8, 0, 6, 1, 4, 3 };
+int8_t simplex_67[] = { 15, 11, 13, 13, 11, 14, 8, 14, 6, 13, 4, 11, 3, 8, 3, 6, 4, 3, 6, 1, 8, 0, 11, 0, 13, 1, 15, 3 };
+int8_t simplex_68[] = { 15, 21, 15, 0, -1, -1, 15, 11, 13, 13, 11, 14, 8, 14, 6, 13, 4, 11, 3, 8, 3, 6, 4, 3, 6, 1, 8, 0, 11, 0, 13, 1, 15, 3 };
+int8_t simplex_69[] = { 3, 8, 15, 8, 15, 10, 14, 12, 13, 13, 11, 14, 8, 14, 6, 13, 4, 11, 3, 8, 3, 6, 4, 3, 6, 1, 8, 0, 11, 0, 13, 1, 15, 3 };
+int8_t simplex_70[] = { 10, 21, 8, 21, 6, 20, 5, 17, 5, 0, -1, -1, 2, 14, 9, 14 };
+int8_t simplex_71[] = { 15, 14, 15, -2, 14, -5, 13, -6, 11, -7, 8, -7, 6, -6, -1, -1, 15, 11, 13, 13, 11, 14, 8, 14, 6, 13, 4, 11, 3, 8, 3, 6, 4, 3, 6, 1, 8, 0, 11, 0, 13, 1, 15, 3 };
+int8_t simplex_72[] = { 4, 21, 4, 0, -1, -1, 4, 10, 7, 13, 9, 14, 12, 14, 14, 13, 15, 10, 15, 0 };
+int8_t simplex_73[] = { 3, 21, 4, 20, 5, 21, 4, 22, 3, 21, -1, -1, 4, 14, 4, 0 };
+int8_t simplex_74[] = { 5, 21, 6, 20, 7, 21, 6, 22, 5, 21, -1, -1, 6, 14, 6, -3, 5, -6, 3, -7, 1, -7 };
+int8_t simplex_75[] = { 4, 21, 4, 0, -1, -1, 14, 14, 4, 4, -1, -1, 8, 8, 15, 0 };
+int8_t simplex_76[] = { 4, 21, 4, 0 };
+int8_t simplex_77[] = { 4, 14, 4, 0, -1, -1, 4, 10, 7, 13, 9, 14, 12, 14, 14, 13, 15, 10, 15, 0, -1, -1, 15, 10, 18, 13, 20, 14, 23, 14, 25, 13, 26, 10, 26, 0 };
+int8_t simplex_78[] = { 4, 14, 4, 0, -1, -1, 4, 10, 7, 13, 9, 14, 12, 14, 14, 13, 15, 10, 15, 0 };
+int8_t simplex_79[] = { 8, 14, 6, 13, 4, 11, 3, 8, 3, 6, 4, 3, 6, 1, 8, 0, 11, 0, 13, 1, 15, 3, 16, 6, 16, 8, 15, 11, 13, 13, 11, 14, 8, 14 };
+int8_t simplex_80[] = { 4, 14, 4, -7, -1, -1, 4, 11, 6, 13, 8, 14, 11, 14, 13, 13, 15, 11, 16, 8, 16, 6, 15, 3, 13, 1, 11, 0, 8, 0, 6, 1, 4, 3 };
+int8_t simplex_81[] = { 15, 14, 15, -7, -1, -1, 15, 11, 13, 13, 11, 14, 8, 14, 6, 13, 4, 11, 3, 8, 3, 6, 4, 3, 6, 1, 8, 0, 11, 0, 13, 1, 15, 3 };
+int8_t simplex_82[] = { 4, 14, 4, 0, -1, -1, 4, 8, 5, 11, 7, 13, 9, 14, 12, 14 };
+int8_t simplex_83[] = { 14, 11, 13, 13, 10, 14, 7, 14, 4, 13, 3, 11, 4, 9, 6, 8, 11, 7, 13, 6, 14, 4, 14, 3, 13, 1, 10, 0, 7, 0, 4, 1, 3, 3 };
+int8_t simplex_84[] = { 5, 21, 5, 4, 6, 1, 8, 0, 10, 0, -1, -1, 2, 14, 9, 14 };
+int8_t simplex_85[] = { 4, 14, 4, 4, 5, 1, 7, 0, 10, 0, 12, 1, 15, 4, -1, -1, 15, 14, 15, 0 };
+int8_t simplex_86[] = { 2, 14, 8, 0, -1, -1, 14, 14, 8, 0 };
+int8_t simplex_87[] = { 3, 14, 7, 0, -1, -1, 11, 14, 7, 0, -1, -1, 11, 14, 15, 0, -1, -1, 19, 14, 15, 0 };
+int8_t simplex_88[] = { 3, 14, 14, 0, -1, -1, 14, 14, 3, 0 };
+int8_t simplex_89[] = { 2, 14, 8, 0, -1, -1, 14, 14, 8, 0, 6, -4, 4, -6, 2, -7, 1, -7 };
+int8_t simplex_90[] = { 14, 14, 3, 0, -1, -1, 3, 14, 14, 14, -1, -1, 3, 0, 14, 0 };
+int8_t simplex_91[] = { 9, 25, 7, 24, 6, 23, 5, 21, 5, 19, 6, 17, 7, 16, 8, 14, 8, 12, 6, 10, -1, -1, 7, 24, 6, 22, 6, 20, 7, 18, 8, 17, 9, 15, 9, 13, 8, 11, 4, 9, 8, 7, 9, 5, 9, 3, 8, 1, 7, 0, 6, -2, 6, -4, 7, -6, -1, -1, 6, 8, 8, 6, 8, 4, 7, 2, 6, 1, 5, -1, 5, -3, 6, -5, 7, -6, 9, -7 };
+int8_t simplex_92[] = { 4, 25, 4, -7 };
+int8_t simplex_93[] = { 5, 25, 7, 24, 8, 23, 9, 21, 9, 19, 8, 17, 7, 16, 6, 14, 6, 12, 8, 10, -1, -1, 7, 24, 8, 22, 8, 20, 7, 18, 6, 17, 5, 15, 5, 13, 6, 11, 10, 9, 6, 7, 5, 5, 5, 3, 6, 1, 7, 0, 8, -2, 8, -4, 7, -6, -1, -1, 8, 8, 6, 6, 6, 4, 7, 2, 8, 1, 9, -1, 9, -3, 8, -5, 7, -6, 5, -7 };
+int8_t simplex_94[] = { 3, 6, 3, 8, 4, 11, 6, 12, 8, 12, 10, 11, 14, 8, 16, 7, 18, 7, 20, 8, 21, 10, -1, -1, 3, 8, 4, 10, 6, 11, 8, 11, 10, 10, 14, 7, 16, 6, 18, 6, 20, 7, 21, 10, 21, 12 };
+
+struct glyph {
+    uint8_t width;
+    uint8_t length;
+    int8_t *data;
+};
+
+// Font data From Hershey Simplex Font
+// http://paulbourke.net/dataformats/hershey/
+glyph simplex[127] = {
+    [' ']  = { .width = 16, .length = sizeof(simplex_0), .data = simplex_0 },
+    ['!']  = { .width = 10, .length = sizeof(simplex_1), .data = simplex_1 },
+    ['"']  = { .width = 16, .length = sizeof(simplex_2), .data = simplex_2 },
+    ['#']  = { .width = 21, .length = sizeof(simplex_3), .data = simplex_3 },
+    ['$']  = { .width = 20, .length = sizeof(simplex_4), .data = simplex_4 },
+    ['%']  = { .width = 24, .length = sizeof(simplex_5), .data = simplex_5 },
+    ['&']  = { .width = 26, .length = sizeof(simplex_6), .data = simplex_6 },
+    ['\''] = { .width = 10, .length = sizeof(simplex_7), .data = simplex_7 },
+    ['(']  = { .width = 14, .length = sizeof(simplex_8), .data = simplex_8 },
+    [')']  = { .width = 14, .length = sizeof(simplex_9), .data = simplex_9 },
+    ['*']  = { .width = 16, .length = sizeof(simplex_10), .data = simplex_10 },
+    ['+']  = { .width = 26, .length = sizeof(simplex_11), .data = simplex_11 },
+    [',']  = { .width = 10, .length = sizeof(simplex_12), .data = simplex_12 },
+    ['-']  = { .width = 26, .length = sizeof(simplex_13), .data = simplex_13 },
+    ['.']  = { .width = 10, .length = sizeof(simplex_14), .data = simplex_14 },
+    ['/']  = { .width = 22, .length = sizeof(simplex_15), .data = simplex_15 },
+    ['0']  = { .width = 20, .length = sizeof(simplex_16), .data = simplex_16 },
+    ['1']  = { .width = 20, .length = sizeof(simplex_17), .data = simplex_17 },
+    ['2']  = { .width = 20, .length = sizeof(simplex_18), .data = simplex_18 },
+    ['3']  = { .width = 20, .length = sizeof(simplex_19), .data = simplex_19 },
+    ['4']  = { .width = 20, .length = sizeof(simplex_20), .data = simplex_20 },
+    ['5']  = { .width = 20, .length = sizeof(simplex_21), .data = simplex_21 },
+    ['6']  = { .width = 20, .length = sizeof(simplex_22), .data = simplex_22 },
+    ['7']  = { .width = 20, .length = sizeof(simplex_23), .data = simplex_23 },
+    ['8']  = { .width = 20, .length = sizeof(simplex_24), .data = simplex_24 },
+    ['9']  = { .width = 20, .length = sizeof(simplex_25), .data = simplex_25 },
+    [':']  = { .width = 10, .length = sizeof(simplex_26), .data = simplex_26 },
+    [';']  = { .width = 10, .length = sizeof(simplex_27), .data = simplex_27 },
+    ['<']  = { .width = 24, .length = sizeof(simplex_28), .data = simplex_28 },
+    ['=']  = { .width = 26, .length = sizeof(simplex_29), .data = simplex_29 },
+    ['>']  = { .width = 24, .length = sizeof(simplex_30), .data = simplex_30 },
+    ['?']  = { .width = 18, .length = sizeof(simplex_31), .data = simplex_31 },
+    ['@']  = { .width = 27, .length = sizeof(simplex_32), .data = simplex_32 },
+    ['A']  = { .width = 18, .length = sizeof(simplex_33), .data = simplex_33 },
+    ['B']  = { .width = 21, .length = sizeof(simplex_34), .data = simplex_34 },
+    ['C']  = { .width = 21, .length = sizeof(simplex_35), .data = simplex_35 },
+    ['D']  = { .width = 21, .length = sizeof(simplex_36), .data = simplex_36 },
+    ['E']  = { .width = 19, .length = sizeof(simplex_37), .data = simplex_37 },
+    ['F']  = { .width = 18, .length = sizeof(simplex_38), .data = simplex_38 },
+    ['G']  = { .width = 21, .length = sizeof(simplex_39), .data = simplex_39 },
+    ['H']  = { .width = 22, .length = sizeof(simplex_40), .data = simplex_40 },
+    ['I']  = { .width =  8, .length = sizeof(simplex_41), .data = simplex_41 },
+    ['J']  = { .width = 16, .length = sizeof(simplex_42), .data = simplex_42 },
+    ['K']  = { .width = 21, .length = sizeof(simplex_43), .data = simplex_43 },
+    ['L']  = { .width = 17, .length = sizeof(simplex_44), .data = simplex_44 },
+    ['M']  = { .width = 24, .length = sizeof(simplex_45), .data = simplex_45 },
+    ['N']  = { .width = 22, .length = sizeof(simplex_46), .data = simplex_46 },
+    ['O']  = { .width = 22, .length = sizeof(simplex_47), .data = simplex_47 },
+    ['P']  = { .width = 21, .length = sizeof(simplex_48), .data = simplex_48 },
+    ['Q']  = { .width = 22, .length = sizeof(simplex_49), .data = simplex_49 },
+    ['R']  = { .width = 21, .length = sizeof(simplex_50), .data = simplex_50 },
+    ['S']  = { .width = 20, .length = sizeof(simplex_51), .data = simplex_51 },
+    ['T']  = { .width = 16, .length = sizeof(simplex_52), .data = simplex_52 },
+    ['U']  = { .width = 22, .length = sizeof(simplex_53), .data = simplex_53 },
+    ['V']  = { .width = 18, .length = sizeof(simplex_54), .data = simplex_54 },
+    ['W']  = { .width = 24, .length = sizeof(simplex_55), .data = simplex_55 },
+    ['X']  = { .width = 20, .length = sizeof(simplex_56), .data = simplex_56 },
+    ['Y']  = { .width = 18, .length = sizeof(simplex_57), .data = simplex_57 },
+    ['Z']  = { .width = 20, .length = sizeof(simplex_58), .data = simplex_58 },
+    ['[']  = { .width = 14, .length = sizeof(simplex_59), .data = simplex_59 },
+    ['\\'] = { .width = 14, .length = sizeof(simplex_60), .data = simplex_60 },
+    [']']  = { .width = 14, .length = sizeof(simplex_61), .data = simplex_61 },
+    ['^']  = { .width = 16, .length = sizeof(simplex_62), .data = simplex_62 },
+    ['_']  = { .width = 16, .length = sizeof(simplex_63), .data = simplex_63 },
+    ['`']  = { .width = 10, .length = sizeof(simplex_64), .data = simplex_64 },
+    ['a']  = { .width = 19, .length = sizeof(simplex_65), .data = simplex_65 },
+    ['b']  = { .width = 19, .length = sizeof(simplex_66), .data = simplex_66 },
+    ['c']  = { .width = 18, .length = sizeof(simplex_67), .data = simplex_67 },
+    ['d']  = { .width = 19, .length = sizeof(simplex_68), .data = simplex_68 },
+    ['e']  = { .width = 18, .length = sizeof(simplex_69), .data = simplex_69 },
+    ['f']  = { .width = 12, .length = sizeof(simplex_70), .data = simplex_70 },
+    ['g']  = { .width = 19, .length = sizeof(simplex_71), .data = simplex_71 },
+    ['h']  = { .width = 19, .length = sizeof(simplex_72), .data = simplex_72 },
+    ['i']  = { .width =  8, .length = sizeof(simplex_73), .data = simplex_73 },
+    ['j']  = { .width = 10, .length = sizeof(simplex_74), .data = simplex_74 },
+    ['k']  = { .width = 17, .length = sizeof(simplex_75), .data = simplex_75 },
+    ['l']  = { .width =  8, .length = sizeof(simplex_76), .data = simplex_76 },
+    ['m']  = { .width = 30, .length = sizeof(simplex_77), .data = simplex_77 },
+    ['n']  = { .width = 19, .length = sizeof(simplex_78), .data = simplex_78 },
+    ['o']  = { .width = 19, .length = sizeof(simplex_79), .data = simplex_79 },
+    ['p']  = { .width = 19, .length = sizeof(simplex_80), .data = simplex_80 },
+    ['q']  = { .width = 19, .length = sizeof(simplex_81), .data = simplex_81 },
+    ['r']  = { .width = 13, .length = sizeof(simplex_82), .data = simplex_82 },
+    ['s']  = { .width = 17, .length = sizeof(simplex_83), .data = simplex_83 },
+    ['t']  = { .width = 12, .length = sizeof(simplex_84), .data = simplex_84 },
+    ['u']  = { .width = 19, .length = sizeof(simplex_85), .data = simplex_85 },
+    ['v']  = { .width = 16, .length = sizeof(simplex_86), .data = simplex_86 },
+    ['w']  = { .width = 22, .length = sizeof(simplex_87), .data = simplex_87 },
+    ['x']  = { .width = 17, .length = sizeof(simplex_88), .data = simplex_88 },
+    ['y']  = { .width = 16, .length = sizeof(simplex_89), .data = simplex_89 },
+    ['z']  = { .width = 17, .length = sizeof(simplex_90), .data = simplex_90 },
+    ['{']  = { .width = 14, .length = sizeof(simplex_91), .data = simplex_91 },
+    ['|']  = { .width =  8, .length = sizeof(simplex_92), .data = simplex_92 },
+    ['}']  = { .width = 14, .length = sizeof(simplex_93), .data = simplex_93 },
+    ['~']  = { .width = 24, .length = sizeof(simplex_94), .data = simplex_94 }
+};
+
+
+using namespace llmr;
+
+debug_font_buffer::debug_font_buffer()
+    : buffer(0),
+      dirty(true) {
+
+}
+
+debug_font_buffer::~debug_font_buffer() {
+    if (buffer != 0) {
+        glDeleteBuffers(1, &buffer);
+    }
+}
+
+void debug_font_buffer::addText(const char *text, double left, double baseline, double scale) {
+    int32_t length = strlen(text);
+    for (int32_t i = 0; i < length; i++) {
+        if (text[i] < 32 || text[i] > 127) {
+            continue;
+        }
+        glyph &glyph = simplex[(int)text[i]];
+        if (!glyph.width) {
+            continue;
+        }
+
+        int16_t prev_x = -1, prev_y = -1, prev = false;
+        for (int32_t j = 0; j < glyph.length; j += 2) {
+            if (glyph.data[j] == -1 && glyph.data[j + 1] == -1) {
+                prev = false;
+            } else {
+                int16_t x = round(left + glyph.data[j] * scale);
+                int16_t y = round(baseline - glyph.data[j + 1] * scale);
+                if (prev) {
+                    array.push_back(prev_x);
+                    array.push_back(prev_y);
+                    array.push_back(x);
+                    array.push_back(y);
+                }
+                prev_x = x; prev_y = y; prev = true;
+            }
+        }
+        left += glyph.width * scale;
+    }
+
+    dirty = true;
+}
+
+void debug_font_buffer::clear() {
+    array.clear();
+    dirty = true;
+}
+
+
+uint32_t debug_font_buffer::length() {
+    // We store 2 coordinates per vertex
+    return array.size() / 2;
+}
+
+void debug_font_buffer::bind() {
+    if (buffer == 0) {
+        glGenBuffers(1, &buffer);
+        glBindBuffer(GL_ARRAY_BUFFER, buffer);
+    } else {
+        glBindBuffer(GL_ARRAY_BUFFER, buffer);
+    }
+
+    if (dirty) {
+        glBufferData(GL_ARRAY_BUFFER, array.size() * sizeof(uint16_t), array.data(), GL_STATIC_DRAW);
+        dirty = false;
+    }
+}
diff --git a/src/map/map.cpp b/src/map/map.cpp
index 7acede3d4e..6bbe7dce5e 100644
--- a/src/map/map.cpp
+++ b/src/map/map.cpp
@@ -253,6 +253,8 @@ void map::updateTiles() {
     });
 
     // Sort tiles by zoom level, front to back.
+    // We're painting front-to-back, so we want to draw more detailed tiles first
+    // before filling in other parts with lower zoom levels.
     tiles.sort([](const tile::ptr& a, const tile::ptr& b) {
         return a->id.z > b->id.z;
     });
diff --git a/src/map/tile.cpp b/src/map/tile.cpp
index 2b99f23722..c7d62bd064 100644
--- a/src/map/tile.cpp
+++ b/src/map/tile.cpp
@@ -66,6 +66,11 @@ tile::tile(tile_id id)
       state(initial),
       data(0),
       bytes(0) {
+
+    // Initialize tile debug coordinates
+    char coord[32];
+    snprintf(coord, sizeof(coord), "%d/%d/%d", id.z, id.x, id.y);
+    debugFontVertex.addText(coord, 50, 200, 5);
 }
 
 tile::~tile() {
diff --git a/src/renderer/painter.cpp b/src/renderer/painter.cpp
index 8c677e1cf9..e231852d29 100644
--- a/src/renderer/painter.cpp
+++ b/src/renderer/painter.cpp
@@ -167,6 +167,29 @@ void painter::render(tile::ptr tile) {
     glUniform4f(lineShader->u_color, 1.0f, 1.0f, 1.0f, 1.0f);
     glLineWidth(4.0f);
     glDrawArrays(GL_LINE_STRIP, 0, sizeof(tile_border_vertices));
+
+
+    // draw debug info
+    switchShader(lineShader);
+    glUniformMatrix4fv(lineShader->u_matrix, 1, GL_FALSE, matrix);
+    tile->debugFontVertex.bind();
+    glVertexAttribPointer(lineShader->a_pos, 2, GL_SHORT, GL_FALSE, 0, BUFFER_OFFSET(0));
+    glUniform4f(lineShader->u_color, 1.0f, 1.0f, 1.0f, 1.0f);
+    glLineWidth(4.0f);
+    glDrawArrays(GL_LINES, 0, tile->debugFontVertex.length());
+    glUniform4f(lineShader->u_color, 0.0f, 0.0f, 0.0f, 1.0f);
+    glLineWidth(2.0f);
+    glDrawArrays(GL_LINES, 0, tile->debugFontVertex.length());
+
+    //     gl.bindBuffer(gl.ARRAY_BUFFER, painter.textBuffer);
+    // gl.bufferData(gl.ARRAY_BUFFER, new Int16Array(vertices), gl.STREAM_DRAW);
+    // gl.vertexAttribPointer(painter.debugShader.a_pos, painter.bufferProperties.textItemSize, gl.SHORT, false, 0, 0);
+    // gl.lineWidth(8 * window.devicePixelRatio);
+    // gl.uniform4f(painter.debugShader.u_color, 1, 1, 1, 1);
+    // gl.drawArrays(gl.LINES, 0, vertices.length / painter.bufferProperties.textItemSize);
+    // gl.lineWidth(2 * window.devicePixelRatio);
+    // gl.uniform4f(painter.debugShader.u_color, 0, 0, 0, 1);
+    // gl.drawArrays(gl.LINES, 0, vertices.length / painter.bufferProperties.textItemSize);
 }
 
 void painter::viewport() {