Far improved font rendering and metrics

Author: darkuranium

CMakeLists.txt

@@ -2,7 +2,7 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
 
 SET(SG_VERSION_MAJOR "0")
 SET(SG_VERSION_MINOR "7")
-SET(SG_VERSION_PATCH "8")
+SET(SG_VERSION_PATCH "9")
 
 #ADD_DEFINITIONS(
 #    "-DSG_VERSION_MAJOR=${SG_VERSION_MAJOR}"

include/siege/backend/fonts/chars.h

@@ -1,16 +1,16 @@
 /*
-    Copyright (c) 2007 SIEGE Development Team
-    All rights reserved.
-
-    This file is part of libSIEGE.
-
-    This software is copyrighted work licensed under the terms of the
-    2-clause BSD license. Please consult the file "license.txt" for
-    details.
-
-    If you did not recieve the file with this program, please email
-    Tim Chas <darkuranium@gmail.com>.
-*/
+ * Copyright (c) 2007 SIEGE Development Team
+ * All rights reserved.
+ *
+ * This file is part of libSIEGE.
+ *
+ * This software is copyrighted work licensed under the terms of the
+ * 2-clause BSD license. Please consult the file "license.txt" for
+ * details.
+ *
+ * If you did not recieve the file with this program, please email
+ * Tim Chas <darkuranium@gmail.com>.
+ */
 
 #ifndef __SIEGE_BACKEND_FONTS_CHARS_H__
 #define __SIEGE_BACKEND_FONTS_CHARS_H__
@@ -25,8 +25,9 @@
 extern "C"
 {
 #endif
-    SGuint SG_EXPORT SG_FPTR(sgmFontsCharsCreate)(void* face, SGuint* chars, SGuint charnum, float* width, float* height, float* prex, float* prey, float* postx, float* posty, SGuint* datawidth, SGuint* dataheight, void** data);
-    SGuint SG_EXPORT SG_FPTR(sgmFontsCharsFreeData)(void* data);
+    SGenum SG_EXPORT SG_FPTR(sgmFontsCharsCreate)(void* face, const SGdchar* chars, size_t numchars, float* width, float* height, float* prex, float* prey, float* postx, float* posty, size_t* datawidth, size_t* dataheight, void** data);
+    SGenum SG_EXPORT SG_FPTR(sgmFontsCharsFreeData)(void* data);
+    SGenum SG_EXPORT SG_FPTR(sgmFontsCharsGetKerning)(void* face, const SGdchar* chars, size_t numchars, float* kerning);
 #ifdef __cplusplus
 }
 #endif

include/siege/backend/fonts/face.h

@@ -5,7 +5,7 @@
  * This file is part of libSIEGE.
  *
  * This software is copyrighted work licensed under the terms of the
- * 2-clause BSD license. Please consult the file "license.txt" for
+ * 2-clause BSD license. Please consult the file "COPYING.txt" for
  * details.
  *
  * If you did not recieve the file with this program, please email
@@ -27,9 +27,9 @@ extern "C"
 {
 #endif
     SGenum SG_EXPORT SG_FPTR(sgmFontsFaceCreate)(void** face, SGStream* stream);
-    SGuint SG_EXPORT SG_FPTR(sgmFontsFaceDestroy)(void* face);
-    SGuint SG_EXPORT SG_FPTR(sgmFontsFaceSetHeight)(void* face, float height);
-    //SGuint SG_EXPORT sgmFontsFaceGetHeight(void* face, float* height);
+    SGenum SG_EXPORT SG_FPTR(sgmFontsFaceDestroy)(void* face);
+    SGenum SG_EXPORT SG_FPTR(sgmFontsFaceSetHeight)(void* face, float height, SGuint dpi);
+    SGenum SG_EXPORT SG_FPTR(sgmFontsFaceGetMetrics)(void* face, float* ascent, float* descent, float* linegap);
 #ifdef __cplusplus
 }
 #endif

include/siege/common.h

@@ -137,7 +137,7 @@ typedef double SGdouble;
 /// @{
 #define SG_VERSION_MAJOR 0
 #define SG_VERSION_MINOR 7
-#define SG_VERSION_PATCH 8
+#define SG_VERSION_PATCH 9
 /**
  * \brief Version string
  *

include/siege/graphics/font.h

@@ -74,8 +74,8 @@ typedef struct SGCharInfo
 	 * \name Bitmap size
 	 */
 	/// @{
-	SGuint dwidth;
-	SGuint dheight;
+	size_t dwidth;
+	size_t dheight;
 	/// @}
 
 	/**
@@ -116,15 +116,21 @@ typedef struct SGFont
 	 */
 	void* handle;
 	float height;	/// < Height of the font
+    SGuint dpi;
 	/// @}
 
+    float ascent;
+    float descent;
+    float linegap;
+
 	// char, wchar_t, utf8, utf16
 	SGConv* conv[4];
 
 	/**
 	 * \name Preloaded characters
 	 */
 	/// @{
+    size_t npreload;
 	SGuint numchars;	/// < The number of characters
 	SGCharInfo* chars;	/// < The characters themselves
 	/// @}
@@ -156,7 +162,7 @@ SGdchar* SG_EXPORT _sgFontU8ToU32(SGFont* font, const SGchar* text);
 SGdchar* SG_EXPORT _sgFontWToU32(SGFont* font, const wchar_t* text);
 SGdchar* SG_EXPORT _sgFontToU32(SGFont* font, const char* text);
 
-SGFont* SG_EXPORT sgFontCreateStream(SGStream* stream, SGbool delstream, float height, SGuint preload);
+SGFont* SG_EXPORT sgFontCreateStream(SGStream* stream, SGbool delstream, float height, SGuint dpi, SGuint preload);
 /// @{
 /**
  * \brief Load a font
@@ -177,48 +183,8 @@ SGFont* SG_EXPORT sgFontCreate(const char* fname, float height, SGuint preload);
 void SG_EXPORT sgFontDestroy(SGFont* font);
 /// @}
 
-/* resize functions temporarily removed */
-
-/**
- * \name Resizing
- */
-/// @{
-/**
- * \brief Resize the font, force duplication.
- * 
- * \param font The font to resize
- * \param height New font height
- *
- * \return A copy of the font, with the height \a height.
- *
- * This resizes the font and forces for it to be duplicated even
- * if the character data for the new size has already been created.
- * 
- * It is roughly equivalent to:
- * \code
- *	sgFontCreate(font->fname, font->height, font->preload);
- * \endcode
- *
- * \see sgFontResize
- */
-
-//SGFont* SG_EXPORT sgFontResizeCopy(SGFont* font, float height);
-/**
- * \brief Resize the font, duplicating only if necessarry.
- *
- * \param font The font to resize
- * \param height New font height
- *
- * \return A new font if one had to be created;
- * otherwise a previously-created font.
- *
- * This function is similar to sgFontResizeCopy(), only it
- * does not allocate a new font if it doesn't have to.
- *
- * \see	sgFontResizeCopy
- */
-//SGFont* SG_EXPORT sgFontResize(SGFont* font, float height);
-/// @}
+void SG_EXPORT sgFontClearCache(SGFont* font);
+void SG_EXPORT sgFontSetHeight(SGFont* font, float height, SGuint dpi);
 
 /**
  * \name Printing

src/modules/SGModule-Freetype/load.c

@@ -94,28 +94,36 @@ SGenum SG_EXPORT sgmFontsFaceCreate(void** face, SGStream* stream)
         return SG_UNKNOWN_ERROR;
     return SG_OK;
 }
-SGuint SG_EXPORT sgmFontsFaceDestroy(void* face)
+SGenum SG_EXPORT sgmFontsFaceDestroy(void* face)
 {
     if(face == NULL)
         return SG_OK; // SG_INVALID_VALUE
     FT_Done_Face(((FontFace*)face)->ftface);
     free(face);
     return SG_OK;
 }
-SGuint SG_EXPORT sgmFontsFaceSetHeight(void* face, float height)
+
+SGenum SG_EXPORT sgmFontsFaceSetHeight(void* face, float height, SGuint dpi)
 {
     if(face == NULL)
         return SG_OK; // SG_INVALID_VALUE
     ((FontFace*)face)->height = height;
-    FT_Set_Char_Size(((FontFace*)face)->ftface, (SGuint)(height * 64), (SGuint)(height * 64), 72, 72);
+    FT_Set_Char_Size(((FontFace*)face)->ftface, (SGuint)(height * 64), (SGuint)(height * 64), dpi, dpi);
     return SG_OK;
 }
-/*SGuint SG_EXPORT sgmFontsFaceGetHeight(void* face, float* height)
+SGenum SG_EXPORT sgmFontsFaceGetMetrics(void* face, float* ascent, float* descent, float* linegap)
 {
-    *height = ((FontFace*)face)->height;
+    if(!face) return SG_INVALID_VALUE;
+    FontFace* fface = face;
+
+    *ascent = fface->ftface->size->metrics.ascender / 64.0;
+    *descent = fface->ftface->size->metrics.descender / 64.0;
+    *linegap = fface->ftface->size->metrics.height / 64.0 + *descent - *ascent;
+
     return SG_OK;
-}*/
-SGuint SG_EXPORT sgmFontsCharsCreate(void* face, SGuint* chars, SGuint charnum, float* width, float* height, float* prex, float* prey, float* postx, float* posty, SGuint* datawidth, SGuint* dataheight, void** data)
+}
+
+SGenum SG_EXPORT sgmFontsCharsCreate(void* face, const SGdchar* chars, size_t numchars, float* width, float* height, float* prex, float* prey, float* postx, float* posty, size_t* datawidth, size_t* dataheight, void** data)
 {
     if(face == NULL)
     {
@@ -137,8 +145,8 @@ SGuint SG_EXPORT sgmFontsCharsCreate(void* face, SGuint* chars, SGuint charnum,
     FT_Glyph glyph;
     FT_BitmapGlyph bitmap_glyph;
     FT_Bitmap bitmap;
-    SGuint i/*, j*/;
-    for(i = 0; i < charnum; i++)
+    SGuint i;
+    for(i = 0; i < numchars; i++)
     {
         ret = FT_Load_Glyph(fface->ftface, FT_Get_Char_Index(fface->ftface, chars[i]), FT_LOAD_DEFAULT);
         if(ret)
@@ -160,27 +168,45 @@ SGuint SG_EXPORT sgmFontsCharsCreate(void* face, SGuint* chars, SGuint charnum,
 
         data[i] = malloc(bitmap.width * bitmap.rows);
         memcpy(data[i], bitmap.buffer, bitmap.width * bitmap.rows);
-        /*for(j = 0; j < bitmap.rows; j++)
-            memcpy((char*)data[i] + j * bitmap.width, bitmap.buffer + (bitmap.rows - j - 1) * bitmap.width, bitmap.width);*/
 
         prex[i] = bitmap_glyph->left;
-        //prey[i] = -bitmap_glyph->top + bitmap.rows;
         prey[i] = -bitmap_glyph->top;
 
         postx[i] = fface->ftface->glyph->advance.x / 64.0;
         posty[i] = 0;
 
-        width[i] = fface->ftface->glyph->/*bitmap.width*/advance.x / 64.0;
-        height[i] = fface->height;
+        width[i] = fface->ftface->glyph->metrics.width;
+        height[i] = fface->ftface->glyph->metrics.height;
 
         FT_Done_Glyph(glyph);
     }
 
     return SG_OK;
 }
-
-SGuint SG_EXPORT sgmFontsCharsFreeData(void* data)
+SGenum SG_EXPORT sgmFontsCharsFreeData(void* data)
 {
     free(data);
     return SG_OK;
 }
+
+SGenum SG_EXPORT sgmFontsCharsGetKerning(void* face, const SGdchar* chars, size_t numchars, float* kerning)
+{
+    if(!face) return SG_INVALID_VALUE;
+    FontFace* fface = face;
+
+    FT_Vector vec;
+
+    FT_UInt prev = numchars ? FT_Get_Char_Index(fface->ftface, chars[0]) : 0;
+    FT_UInt curr;
+
+    size_t i;
+    for(i = 1; i < numchars; i++)
+    {
+        curr = FT_Get_Char_Index(fface->ftface, chars[i]);
+        FT_Get_Kerning(fface->ftface, prev, curr, FT_KERNING_DEFAULT, &vec);
+        kerning[i-1] = vec.x / 64.0;
+        prev = curr;
+    }
+
+    return SG_OK;
+}

src/modules/SGModule-STB-TrueType/load.c

@@ -20,7 +20,7 @@ typedef struct FontFace
 {
     stbtt_fontinfo info;
     void* buf;
-    float height;
+    float scale;
 } FontFace;
 
 SGenum SG_EXPORT sgmFontsFaceCreate(void** face, SGStream* stream)
@@ -50,6 +50,8 @@ SGenum SG_EXPORT sgmFontsFaceCreate(void** face, SGStream* stream)
         goto err;
     stbtt_InitFont(&fface->info, fface->buf, 0);
 
+    fface->scale = 1.0;
+
     return SG_OK;
 
 err:
@@ -64,50 +66,74 @@ SGenum SG_EXPORT sgmFontsFaceDestroy(void* face)
     free(fface);
     return SG_OK;
 }
-SGenum SG_EXPORT sgmFontsFaceSetHeight(void* face, float height)
+
+SGenum SG_EXPORT sgmFontsFaceSetHeight(void* face, float height, SGuint dpi)
 {
     if(!face) return SG_INVALID_VALUE;
     FontFace* fface = face;
-    fface->height = height;
+    //fface->scale = stbtt_ScaleForPixelHeight(&fface->info, height);
+    fface->scale = stbtt_ScaleForMappingEmToPixels(&fface->info, height * dpi / 72.0);
     return SG_OK;
 }
-SGenum SG_EXPORT sgmFontsCharsCreate(void* face, SGuint* chars, SGuint charnum, float* width, float* height, float* prex, float* prey, float* postx, float* posty, SGuint* datawidth, SGuint* dataheight, void** data)
+SGenum SG_EXPORT sgmFontsFaceGetMetrics(void* face, float* ascent, float* descent, float* linegap)
+{
+    if(!face) return SG_INVALID_VALUE;
+    FontFace* fface = face;
+
+    int iasc, idesc, igap;
+    stbtt_GetFontVMetrics(&fface->info, &iasc, &idesc, &igap);
+    *ascent = iasc * fface->scale;
+    *descent = idesc * fface->scale;
+    *linegap = igap * fface->scale;
+
+    return SG_OK;
+}
+
+SGenum SG_EXPORT sgmFontsCharsCreate(void* face, const SGdchar* chars, size_t numchars, float* width, float* height, float* prex, float* prey, float* postx, float* posty, size_t* datawidth, size_t* dataheight, void** data)
 {
     if(!face) return SG_INVALID_VALUE;
 
     FontFace* fface = (FontFace*)face;
-    //float scale = stbtt_ScaleForPixelHeight(&fface->info, fface->height);
-    float scale = stbtt_ScaleForMappingEmToPixels(&fface->info, fface->height);
 
     int adv, left;
     int dw, dh;
     int xo, yo;
-    int kern = 0;
 
     int glyph;
     size_t i;
-    for(i = 0; i < charnum; i++)
+    for(i = 0; i < numchars; i++)
     {
         glyph = stbtt_FindGlyphIndex(&fface->info, chars[i]);
 
-        data[i] = stbtt_GetGlyphBitmap(&fface->info, scale, scale, glyph, &dw, &dh, &xo, &yo);
+        data[i] = stbtt_GetGlyphBitmap(&fface->info, fface->scale, fface->scale, glyph, &dw, &dh, &xo, &yo);
         datawidth[i] = dw;
         dataheight[i] = dh;
 
-        if(i) kern = stbtt_GetGlyphKernAdvance(&fface->info, chars[i-1], chars[i]);
-
         stbtt_GetGlyphHMetrics(&fface->info, glyph, &adv, &left);
-        prex[i] = (left + kern) * scale + xo;
+        prex[i] = /*-left * fface->scale * 0.5 + */xo;
         prey[i] = yo;
-        postx[i] = adv * scale;
+        postx[i] = adv * fface->scale;
         posty[i] = 0;
+        width[i] = adv * fface->scale;
+        height[i] = 0; /* TODO */
     }
 
     return SG_OK;
 }
-
 SGenum SG_EXPORT sgmFontsCharsFreeData(void* data)
 {
     stbtt_FreeBitmap(data, NULL);
     return SG_OK;
 }
+
+SGenum SG_EXPORT sgmFontsCharsGetKerning(void* face, const SGdchar* chars, size_t numchars, float* kerning)
+{
+    if(!face) return SG_INVALID_VALUE;
+    FontFace* fface = face;
+
+    size_t i;
+    for(i = 1; i < numchars; i++)
+        kerning[i-1] = stbtt_GetCodepointKernAdvance(&fface->info, chars[i-1], chars[i]) * fface->scale;
+
+    return SG_OK;
+}