From 7077d89a22ef51e75e74611eb984acaa195d551f Mon Sep 17 00:00:00 2001
From: bjorn <tie.372@gmail.com>
Date: Thu, 16 Mar 2017 01:12:32 -0700
Subject: [PATCH] Font metrics;

---
 src/api/types/font.c | 37 +++++++++++++++++++++++++++++++++++++
 src/graphics/font.c  | 43 +++++++++++++++++++++++++++++++++++++++++++
 src/graphics/font.h  |  5 +++++
 src/loaders/font.c   |  2 ++
 src/loaders/font.h   |  2 ++
 src/math/math.h      |  4 ++--
 6 files changed, 91 insertions(+), 2 deletions(-)

diff --git a/src/api/types/font.c b/src/api/types/font.c
index faa0f99c..6ad42fdc 100644
--- a/src/api/types/font.c
+++ b/src/api/types/font.c
@@ -1,6 +1,38 @@
 #include "api/lovr.h"
 #include "graphics/font.h"
 
+int l_lovrFontGetWidth(lua_State* L) {
+  Font* font = luax_checktype(L, 1, Font);
+  const char* string = luaL_checkstring(L, 2);
+  float wrap = luaL_optnumber(L, 3, 0);
+  lua_pushnumber(L, lovrFontGetWidth(font, string, wrap));
+  return 1;
+}
+
+int l_lovrFontGetHeight(lua_State* L) {
+  Font* font = luax_checktype(L, 1, Font);
+  lua_pushnumber(L, lovrFontGetHeight(font));
+  return 1;
+}
+
+int l_lovrFontGetAscent(lua_State* L) {
+  Font* font = luax_checktype(L, 1, Font);
+  lua_pushnumber(L, lovrFontGetAscent(font));
+  return 1;
+}
+
+int l_lovrFontGetDescent(lua_State* L) {
+  Font* font = luax_checktype(L, 1, Font);
+  lua_pushnumber(L, lovrFontGetDescent(font));
+  return 1;
+}
+
+int l_lovrFontGetBaseline(lua_State* L) {
+  Font* font = luax_checktype(L, 1, Font);
+  lua_pushnumber(L, lovrFontGetBaseline(font));
+  return 1;
+}
+
 int l_lovrFontGetLineHeight(lua_State* L) {
   Font* font = luax_checktype(L, 1, Font);
   lua_pushinteger(L, lovrFontGetLineHeight(font));
@@ -28,6 +60,11 @@ int l_lovrFontSetPixelDensity(lua_State* L) {
 }
 
 const luaL_Reg lovrFont[] = {
+  { "getWidth", l_lovrFontGetWidth },
+  { "getHeight", l_lovrFontGetHeight },
+  { "getAscent", l_lovrFontGetAscent },
+  { "getDescent", l_lovrFontGetDescent },
+  { "getBaseline", l_lovrFontGetBaseline },
   { "getLineHeight", l_lovrFontGetLineHeight },
   { "setLineHeight", l_lovrFontSetLineHeight },
   { "getPixelDensity", l_lovrFontGetPixelDensity },
diff --git a/src/graphics/font.c b/src/graphics/font.c
index 4392de44..b89a5256 100644
--- a/src/graphics/font.c
+++ b/src/graphics/font.c
@@ -170,6 +170,49 @@ void lovrFontPrint(Font* font, const char* str, mat4 transform, float wrap, Hori
   lovrGraphicsPop();
 }
 
+float lovrFontGetWidth(Font* font, const char* str, float wrap) {
+  float width = 0;
+  float x = 0;
+  const char* end = str + strlen(str);
+  size_t bytes;
+  unsigned int previous = '\0';
+  unsigned int codepoint;
+  float scale = 1 / font->pixelDensity;
+
+  while ((bytes = utf8_decode(str, end, &codepoint)) > 0) {
+    if (codepoint == '\n' || (wrap && x * scale > wrap && codepoint == ' ')) {
+      width = MAX(width, x) / font->pixelDensity;
+      x = 0;
+      previous = '\0';
+      str += bytes;
+      continue;
+    }
+
+    Glyph* glyph = lovrFontGetGlyph(font, codepoint);
+    x += glyph->advance + lovrFontGetKerning(font, previous, codepoint);
+    previous = codepoint;
+    str += bytes;
+  }
+
+  return MAX(x, width) * scale;
+}
+
+float lovrFontGetHeight(Font* font) {
+  return font->fontData->height / font->pixelDensity;
+}
+
+float lovrFontGetAscent(Font* font) {
+  return font->fontData->ascent / font->pixelDensity;
+}
+
+float lovrFontGetDescent(Font* font) {
+  return font->fontData->descent / font->pixelDensity;
+}
+
+float lovrFontGetBaseline(Font* font) {
+  return font->fontData->height * .8 / font->pixelDensity;
+}
+
 float lovrFontGetLineHeight(Font* font) {
   return font->lineHeight;
 }
diff --git a/src/graphics/font.h b/src/graphics/font.h
index 66c30d20..eb653555 100644
--- a/src/graphics/font.h
+++ b/src/graphics/font.h
@@ -44,6 +44,11 @@ typedef struct {
 Font* lovrFontCreate(FontData* fontData);
 void lovrFontDestroy(const Ref* ref);
 void lovrFontPrint(Font* font, const char* str, mat4 transform, float wrap, HorizontalAlign halign, VerticalAlign valign);
+float lovrFontGetWidth(Font* font, const char* string, float wrap);
+float lovrFontGetHeight(Font* font);
+float lovrFontGetAscent(Font* font);
+float lovrFontGetDescent(Font* font);
+float lovrFontGetBaseline(Font* font);
 float lovrFontGetLineHeight(Font* font);
 void lovrFontSetLineHeight(Font* font, float lineHeight);
 int lovrFontGetKerning(Font* font, unsigned int a, unsigned int b);
diff --git a/src/loaders/font.c b/src/loaders/font.c
index 23f3a705..32e91316 100644
--- a/src/loaders/font.c
+++ b/src/loaders/font.c
@@ -32,6 +32,8 @@ FontData* lovrFontDataCreate(void* data, int size, int height) {
 
   FT_Size_Metrics metrics = face->size->metrics;
   fontData->height = metrics.height >> 6;
+  fontData->ascent = metrics.ascender >> 6;
+  fontData->descent = metrics.descender >> 6;
 
   return fontData;
 }
diff --git a/src/loaders/font.h b/src/loaders/font.h
index 47438f2f..38a1f7cb 100644
--- a/src/loaders/font.h
+++ b/src/loaders/font.h
@@ -7,6 +7,8 @@ typedef struct {
   void* rasterizer;
   int size;
   int height;
+  int ascent;
+  int descent;
 } FontData;
 
 typedef struct {
diff --git a/src/math/math.h b/src/math/math.h
index efba86fb..5857cb50 100644
--- a/src/math/math.h
+++ b/src/math/math.h
@@ -2,8 +2,8 @@
 
 #pragma once
 
-#define MAX(a, b) a > b ? a : b
-#define MIN(a, b) a < b ? a : b
+#define MAX(a, b) (a > b ? a : b)
+#define MIN(a, b) (a < b ? a : b)
 
 typedef float* vec3;
 typedef float* quat;