Move text measuring to Rasterizer

src/api/l_data_rasterizer.c

@@ -54,6 +54,19 @@ static int l_lovrRasterizerHasGlyphs(lua_State* L) {
   return 1;
 }
 
+static int l_lovrRasterizerGetWidth(lua_State* L) {
+  Rasterizer* rasterizer = luax_checktype(L, 1, Rasterizer);
+  size_t length;
+  const char* string = luaL_checklstring(L, 2, &length);
+  float wrap = luax_optfloat(L, 4, 0.f);
+  float width, height;
+  uint32_t lineCount, glyphCount;
+  lovrRasterizerMeasure(rasterizer, string, length, wrap, &width, &height, &lineCount, &glyphCount);
+  lua_pushnumber(L, width);
+  lua_pushnumber(L, lineCount + 1);
+  return 2;
+}
+
 const luaL_Reg lovrRasterizer[] = {
   { "getHeight", l_lovrRasterizerGetHeight },
   { "getAdvance", l_lovrRasterizerGetAdvance },
@@ -62,5 +75,6 @@ const luaL_Reg lovrRasterizer[] = {
   { "getLineHeight", l_lovrRasterizerGetLineHeight },
   { "getGlyphCount", l_lovrRasterizerGetGlyphCount },
   { "hasGlyphs", l_lovrRasterizerHasGlyphs },
+  { "getWidth", l_lovrRasterizerGetWidth },
   { NULL, NULL }
 };

src/modules/data/rasterizer.c

@@ -184,3 +184,54 @@ void lovrRasterizerLoadGlyph(Rasterizer* rasterizer, uint32_t character, uint32_
 int32_t lovrRasterizerGetKerning(Rasterizer* rasterizer, uint32_t left, uint32_t right) {
   return stbtt_GetCodepointKernAdvance(&rasterizer->font, left, right) * rasterizer->scale;
 }
+
+void lovrRasterizerMeasure(Rasterizer* rasterizer, const char* str, size_t length, float wrap, float* width, float* height, uint32_t* lineCount, uint32_t* glyphCount) {
+  float x = 0.f;
+  const char* end = str + length;
+  size_t bytes;
+  unsigned int previous = '\0';
+  unsigned int codepoint;
+  *width = 0.f;
+  *lineCount = 0;
+  *glyphCount = 0;
+
+  while ((bytes = utf8_decode(str, end, &codepoint)) > 0) {
+    if (codepoint == '\n' || (wrap && x > wrap && codepoint == ' ')) {
+      *width = MAX(*width, x);
+      (*lineCount)++;
+      x = 0.f;
+      previous = '\0';
+      str += bytes;
+      continue;
+    }
+
+    // Tabs
+    if (codepoint == '\t') {
+      int glyphIndex = stbtt_FindGlyphIndex(&rasterizer->font, ' ');
+      int advance, bearing;
+      stbtt_GetGlyphHMetrics(&rasterizer->font, glyphIndex, &advance, &bearing);
+      x += advance * 4.f;
+      str += bytes;
+      continue;
+    }
+
+    int glyphIndex = stbtt_FindGlyphIndex(&rasterizer->font, codepoint);
+    int advance, bearing;
+    stbtt_GetGlyphHMetrics(&rasterizer->font, glyphIndex, &advance, &bearing);
+    int x0, y0, x1, y1;
+    stbtt_GetGlyphBox(&rasterizer->font, glyphIndex, &x0, &y0, &x1, &y1);
+    float w = ceilf((x1 - x0) * rasterizer->scale);
+    float h = ceilf((y1 - y0) * rasterizer->scale);
+
+    if (w > 0 && h > 0) {
+      (*glyphCount)++;
+    }
+
+    x += roundf(advance * rasterizer->scale) + lovrRasterizerGetKerning(rasterizer, previous, codepoint);
+    previous = codepoint;
+    str += bytes;
+  }
+
+  *width = MAX(*width, x);
+  *height = ((*lineCount + 1) * lovrRasterizerGetHeight(rasterizer));
+}

src/modules/data/rasterizer.h

@@ -1,5 +1,6 @@
 #include <stdbool.h>
 #include <stdint.h>
+#include <stddef.h>
 
 #pragma once
 
@@ -32,3 +33,4 @@ bool lovrRasterizerHasGlyph(Rasterizer* fontData, uint32_t character);
 bool lovrRasterizerHasGlyphs(Rasterizer* fontData, const char* str);
 void lovrRasterizerLoadGlyph(Rasterizer* fontData, uint32_t character, uint32_t padding, double spread, Glyph* glyph);
 int32_t lovrRasterizerGetKerning(Rasterizer* fontData, uint32_t left, uint32_t right);
+void lovrRasterizerMeasure(Rasterizer* rasterizer, const char* str, size_t length, float wrap, float* width, float* height, uint32_t* lineCount, uint32_t* glyphCount);

src/modules/graphics/font.c

@@ -200,47 +200,10 @@ void lovrFontRender(Font* font, const char* str, size_t length, float wrap, Hori
 }
 
 void lovrFontMeasure(Font* font, const char* str, size_t length, float wrap, float* width, float* height, uint32_t* lineCount, uint32_t* glyphCount) {
-  float x = 0.f;
-  const char* end = str + length;
-  size_t bytes;
-  unsigned int previous = '\0';
-  unsigned int codepoint;
-  float scale = 1.f / font->pixelDensity;
-  *width = 0.f;
-  *lineCount = 0;
-  *glyphCount = 0;
-
-  while ((bytes = utf8_decode(str, end, &codepoint)) > 0) {
-    if (codepoint == '\n' || (wrap && x * scale > wrap && codepoint == ' ')) {
-      *width = MAX(*width, x * scale);
-      (*lineCount)++;
-      x = 0.f;
-      previous = '\0';
-      str += bytes;
-      continue;
-    }
-
-    // Tabs
-    if (codepoint == '\t') {
-      Glyph* space = lovrFontGetGlyph(font, ' ');
-      x += space->advance * 4.f;
-      str += bytes;
-      continue;
-    }
-
-    Glyph* glyph = lovrFontGetGlyph(font, codepoint);
-
-    if (glyph->w > 0 && glyph->h > 0) {
-      (*glyphCount)++;
-    }
-
-    x += glyph->advance + lovrFontGetKerning(font, previous, codepoint);
-    previous = codepoint;
-    str += bytes;
-  }
-
-  *width = MAX(*width, x * scale);
-  *height = ((*lineCount + 1) * lovrRasterizerGetHeight(font->rasterizer) * font->lineHeight) * (font->flip ? -1 : 1);
+  wrap *= font->pixelDensity;
+  lovrRasterizerMeasure(font->rasterizer, str, length, wrap, width, height, lineCount, glyphCount);
+  *width /= font->pixelDensity;
+  *height *= font->lineHeight * (font->flip ? -1 : 1);
 }
 
 uint32_t lovrFontGetPadding(Font* font) {