Font:setFlipEnabled; Font:isFlipEnabled;

src/api/types/font.c

@@ -51,6 +51,18 @@ int l_lovrFontSetLineHeight(lua_State* L) {
   return 0;
 }
 
+int l_lovrFontIsFlipEnabled(lua_State* L) {
+  Font* font = luax_checktype(L, 1, Font);
+  lua_pushboolean(L, lovrFontIsFlipEnabled(font));
+  return 1;
+}
+
+int l_lovrFontSetFlipEnabled(lua_State* L) {
+  Font* font = luax_checktype(L, 1, Font);
+  lovrFontSetFlipEnabled(font, lua_toboolean(L, 2));
+  return 0;
+}
+
 int l_lovrFontGetPixelDensity(lua_State* L) {
   Font* font = luax_checktype(L, 1, Font);
   lua_pushnumber(L, lovrFontGetPixelDensity(font));
@@ -97,6 +109,8 @@ const luaL_Reg lovrFont[] = {
   { "getBaseline", l_lovrFontGetBaseline },
   { "getLineHeight", l_lovrFontGetLineHeight },
   { "setLineHeight", l_lovrFontSetLineHeight },
+  { "isFlipEnabled", l_lovrFontIsFlipEnabled },
+  { "setFlipEnabled", l_lovrFontSetFlipEnabled },
   { "getPixelDensity", l_lovrFontGetPixelDensity },
   { "setPixelDensity", l_lovrFontSetPixelDensity },
   { "getRasterizer", l_lovrFontGetRasterizer},

src/graphics/font.c

@@ -69,9 +69,10 @@ Rasterizer* lovrFontGetRasterizer(Font* font) {
 
 void lovrFontRender(Font* font, const char* str, size_t length, float wrap, HorizontalAlign halign, float* vertices, uint16_t* indices, uint16_t baseVertex) {
   FontAtlas* atlas = &font->atlas;
+  bool flip = font->flip;
 
   float cx = 0;
-  float cy = -font->rasterizer->height * .8;
+  float cy = -font->rasterizer->height * .8 * (flip ? -1 : 1);
   float u = atlas->width;
   float v = atlas->height;
   float scale = 1 / font->pixelDensity;
@@ -93,7 +94,7 @@ void lovrFontRender(Font* font, const char* str, size_t length, float wrap, Hori
     if (codepoint == '\n' || (wrap && cx * scale > wrap && codepoint == ' ')) {
       lineStart = lovrFontAlignLine(lineStart, vertexCursor, cx, halign);
       cx = 0;
-      cy -= font->rasterizer->height * font->lineHeight;
+      cy -= font->rasterizer->height * font->lineHeight * (flip ? -1 : 1);
       previous = '\0';
       str += bytes;
       continue;
@@ -123,9 +124,9 @@ void lovrFontRender(Font* font, const char* str, size_t length, float wrap, Hori
     // Triangles
     if (glyph->w > 0 && glyph->h > 0) {
       float x1 = cx + glyph->dx - GLYPH_PADDING;
-      float y1 = cy + glyph->dy + GLYPH_PADDING;
+      float y1 = cy + (glyph->dy + GLYPH_PADDING) * (flip ? -1 : 1);
       float x2 = x1 + glyph->tw;
-      float y2 = y1 - glyph->th;
+      float y2 = y1 - glyph->th * (flip ? -1 : 1);
       float s1 = glyph->x / u;
       float t1 = (glyph->y + glyph->th) / v;
       float s2 = (glyph->x + glyph->tw) / u;
@@ -221,6 +222,14 @@ void lovrFontSetLineHeight(Font* font, float lineHeight) {
   font->lineHeight = lineHeight;
 }
 
+bool lovrFontIsFlipEnabled(Font* font) {
+  return font->flip;
+}
+
+void lovrFontSetFlipEnabled(Font* font, bool flip) {
+  font->flip = flip;
+}
+
 int lovrFontGetKerning(Font* font, unsigned int left, unsigned int right) {
   char key[12];
   snprintf(key, 12, "%d,%d", left, right);

src/graphics/font.h

@@ -3,6 +3,7 @@
 #include "graphics/texture.h"
 #include "lib/map/map.h"
 #include <stdint.h>
+#include <stdbool.h>
 
 #pragma once
 
@@ -36,6 +37,7 @@ typedef struct {
   map_int_t kerning;
   float lineHeight;
   float pixelDensity;
+  bool flip;
 } Font;
 
 Font* lovrFontInit(Font* font, Rasterizer* rasterizer);
@@ -50,6 +52,8 @@ float lovrFontGetDescent(Font* font);
 float lovrFontGetBaseline(Font* font);
 float lovrFontGetLineHeight(Font* font);
 void lovrFontSetLineHeight(Font* font, float lineHeight);
+bool lovrFontIsFlipEnabled(Font* font);
+void lovrFontSetFlipEnabled(Font* font, bool flip);
 int lovrFontGetKerning(Font* font, unsigned int a, unsigned int b);
 float lovrFontGetPixelDensity(Font* font);
 void lovrFontSetPixelDensity(Font* font, float pixelDensity);

src/graphics/graphics.c

@@ -1015,7 +1015,7 @@ void lovrGraphicsPrint(const char* str, size_t length, mat4 transform, float wra
   lovrFontMeasure(font, str, length, wrap, &width, &lineCount, &glyphCount);
 
   float scale = 1.f / font->pixelDensity;
-  float offsetY = ((lineCount + 1) * font->rasterizer->height * font->lineHeight) * (valign / 2.f);
+  float offsetY = ((lineCount + 1) * font->rasterizer->height * font->lineHeight) * (valign / 2.f) * (font->flip ? -1 : 1);
   mat4_scale(transform, scale, scale, scale);
   mat4_translate(transform, 0.f, offsetY, 0.f);