Work in Progress: font glyph packing

* Removed font size parameter from loadFont functions
* Font class loads a range of font sizes a prior
* Characters have an outline to enable easy reading
* Updated examples to reflect the change related to loadFont functions
* Added a new FontAtlas class that creates the single texture that
  has all the glphs for all font sizes and characters

examples/cpu/bubblechart.cpp

@@ -77,9 +77,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cpu/fractal.cpp

@@ -42,9 +42,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cpu/histogram.cpp

@@ -59,9 +59,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cpu/plot3.cpp

@@ -49,9 +49,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cpu/plotting.cpp

@@ -55,9 +55,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cpu/surface.cpp

@@ -53,9 +53,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cuda/fractal.cu

@@ -26,9 +26,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cuda/histogram.cu

@@ -78,9 +78,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cuda/plot3.cu

@@ -41,9 +41,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cuda/plotting.cu

@@ -35,9 +35,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/cuda/surface.cu

@@ -35,9 +35,9 @@ int main(void)
      * it can be used for rendering text */
     fg::Font fnt;
 #ifdef OS_WIN
-    fnt.loadSystemFont("Calibri", 32);
+    fnt.loadSystemFont("Calibri");
 #else
-    fnt.loadSystemFont("Vera", 32);
+    fnt.loadSystemFont("Vera");
 #endif
     wnd.setFont(&fnt);
 

examples/opencl/fractal.cpp

@@ -118,9 +118,9 @@ int main(void)
         * it can be used for rendering text */
         fg::Font fnt;
 #ifdef OS_WIN
-        fnt.loadSystemFont("Calibri", 32);
+        fnt.loadSystemFont("Calibri");
 #else
-        fnt.loadSystemFont("Vera", 32);
+        fnt.loadSystemFont("Vera");
 #endif
         wnd.setFont(&fnt);
 

examples/opencl/histogram.cpp

@@ -213,9 +213,9 @@ int main(void)
         * it can be used for rendering text */
         fg::Font fnt;
 #ifdef OS_WIN
-        fnt.loadSystemFont("Calibri", 32);
+        fnt.loadSystemFont("Calibri");
 #else
-        fnt.loadSystemFont("Vera", 32);
+        fnt.loadSystemFont("Vera");
 #endif
         wnd.setFont(&fnt);
 

examples/opencl/plot3.cpp

@@ -87,9 +87,9 @@ int main(void)
          * it can be used for rendering text */
         fg::Font fnt;
 #ifdef OS_WIN
-        fnt.loadSystemFont("Calibri", 32);
+        fnt.loadSystemFont("Calibri");
 #else
-        fnt.loadSystemFont("Vera", 32);
+        fnt.loadSystemFont("Vera");
 #endif
         wnd.setFont(&fnt);
 

examples/opencl/plotting.cpp

@@ -90,9 +90,9 @@ int main(void)
         * it can be used for rendering text */
         fg::Font fnt;
 #ifdef OS_WIN
-        fnt.loadSystemFont("Calibri", 32);
+        fnt.loadSystemFont("Calibri");
 #else
-        fnt.loadSystemFont("Vera", 32);
+        fnt.loadSystemFont("Vera");
 #endif
         wnd.setFont(&fnt);
 

examples/opencl/surface.cpp

@@ -93,9 +93,9 @@ int main(void)
          * it can be used for rendering text */
         fg::Font fnt;
 #ifdef OS_WIN
-        fnt.loadSystemFont("Calibri", 32);
+        fnt.loadSystemFont("Calibri");
 #else
-        fnt.loadSystemFont("Vera", 32);
+        fnt.loadSystemFont("Vera");
 #endif
         wnd.setFont(&fnt);
 

include/fg/defines.h

@@ -92,6 +92,11 @@ enum ErrorCode {
      * */
     FG_ERR_NOT_SUPPORTED  = 5001,           ///< Feature not supported
     FG_ERR_NOT_CONFIGURED = 5002,           ///< Library configuration mismatch
+    /*
+     * Font config related error codes
+     * '6**'
+     * */
+    FG_ERR_FONTCONFIG_ERROR = 6001,         ///< Fontconfig related error
     /*
      * other error codes
      * match the following pattern

include/fg/font.h

@@ -49,17 +49,15 @@ class Font {
            Load a given font file
 
            \param[in] pFile True Type Font file path
-           \param[in] pFontSize the size of the font glyphs that will be created
          */
-        FGAPI void loadFont(const char* const pFile, int pFontSize);
+        FGAPI void loadFontFile(const char* const pFile);
 
         /**
            Load a system font based on the name
 
            \param[in] pName True Type Font name
-           \param[in] pFontSize the size of the font glyphs that will be created
          */
-        FGAPI void loadSystemFont(const char* const pName, int pFontSize);
+        FGAPI void loadSystemFont(const char* const pName);
 
         /**
            Get handle for internal implementation of Font object

src/chart.cpp

@@ -42,9 +42,9 @@ const std::shared_ptr<internal::font_impl>& getChartFont()
 
     std::call_once(flag, []() {
 #if defined(OS_WIN)
-        mChartFont.loadSystemFont("Calibri", 32);
+        mChartFont.loadSystemFont("Calibri");
 #else
-        mChartFont.loadSystemFont("Vera", 32);
+        mChartFont.loadSystemFont("Vera");
 #endif
     });
 

src/common.cpp

@@ -158,11 +158,6 @@ GLuint initShaders(const char* pVertShaderSrc, const char* pFragShaderSrc)
     return shaderProgram;
 }
 
-int nextP2(const int pValue)
-{
-    return int(std::pow(2, (std::ceil(std::log2(pValue)))));
-}
-
 float clampTo01(const float pValue)
 {
     return (pValue < 0.0f ? 0.0f : (pValue>1.0f ? 1.0f : pValue));
@@ -316,3 +311,68 @@ glm::vec3 trackballPoint(const float pX, const float pY,
     a = 1.0f / sqrt(x*x + y*y + z*z);
     return glm::vec3(x*a,y*a,z*a);
 }
+
+size_t utf8_surrogate_len(const char* character)
+{
+    size_t result = 0;
+    char test_char;
+
+    if (!character)
+        return 0;
+
+    test_char = character[0];
+
+    if ((test_char & 0x80) == 0)
+        return 1;
+
+    while (test_char & 0x80) {
+        test_char <<= 1;
+        result++;
+    }
+
+    return result;
+}
+
+size_t utf8_strlen(const char* string)
+{
+    const char* ptr = string;
+    size_t result = 0;
+
+    while (*ptr) {
+        ptr += utf8_surrogate_len(ptr);
+        result++;
+    }
+
+    return result;
+}
+
+uint32_t utf8_to_utf32(const char * character)
+{
+    uint32_t result = -1;
+
+    if (!character) {
+        return result;
+    }
+
+    if (( character[0] & 0x80 ) == 0x0) {
+        result = character[0];
+    }
+
+    if (( character[0] & 0xC0 ) == 0xC0) {
+        result = ( ( character[0] & 0x3F ) << 6 ) | ( character[1] & 0x3F );
+    }
+
+    if (( character[0] & 0xE0 ) == 0xE0) {
+        result = ( ( character[0] & 0x1F ) << ( 6 + 6 ) ) | ( ( character[1] & 0x3F ) << 6 ) | ( character[2] & 0x3F );
+    }
+
+    if (( character[0] & 0xF0 ) == 0xF0) {
+        result = ( ( character[0] & 0x0F ) << ( 6 + 6 + 6 ) ) | ( ( character[1] & 0x3F ) << ( 6 + 6 ) ) | ( ( character[2] & 0x3F ) << 6 ) | ( character[3] & 0x3F );
+    }
+
+    if (( character[0] & 0xF8 ) == 0xF8) {
+        result = ( ( character[0] & 0x07 ) << ( 6 + 6 + 6 + 6 ) ) | ( ( character[1] & 0x3F ) << ( 6 + 6 + 6 ) ) | ( ( character[2] & 0x3F ) << ( 6 + 6 ) ) | ( ( character[3] & 0x3F ) << 6 ) | ( character[4] & 0x3F );
+    }
+
+    return result;
+}

src/common.hpp

@@ -86,12 +86,6 @@ GLuint createBuffer(GLenum pTarget, size_t pSize, const T* pPtr, GLenum pUsage)
     return retVal;
 }
 
-/* compute the next power of two after given integer
- *
- * @pValue is the value whose next power of two is to be computed
- */
-int nextP2(const int pValue);
-
 #ifdef OS_WIN
 /* Get the paths to font files in Windows system directory
  *
@@ -134,6 +128,9 @@ std::ostream& operator<<(std::ostream&, const glm::mat4&);
 glm::vec3 trackballPoint(const float pX, const float pY,
                          const float pWidth, const float pHeight);
 
+size_t utf8_surrogate_len(const char* character);
+size_t utf8_strlen(const char* string);
+uint32_t utf8_to_utf32(const char * character);
 
 namespace internal
 {