implement font gamma setting; tune fonts in default theme

examples/example1/example1.visualdproj

@@ -66,7 +66,7 @@
   <debuglevel>0</debuglevel>
   <debugids />
   <versionlevel>0</versionlevel>
-  <versionids>Unicode</versionids>
+  <versionids>Unicode  USE_FREETYPE</versionids>
   <dump_source>0</dump_source>
   <mapverbosity>3</mapverbosity>
   <createImplib>0</createImplib>

src/dlangui/graphics/fonts.d

@@ -584,6 +584,20 @@ class FontManager {
         _subpixelRenderingMode = mode;
     }
 
+    private static __gshared double _fontGamma = 1.0;
+    /// get font gamma (1.0 is neutral, < 1.0 makes glyphs lighter, >1.0 makes glyphs bolder)
+    static @property double fontGamma() { return _fontGamma; }
+    /// set font gamma (1.0 is neutral, < 1.0 makes glyphs lighter, >1.0 makes glyphs bolder)
+    static @property void fontGamma(double v) { 
+        if (v < 0.1)
+            v = 0.1;
+        else if (v > 4)
+            v = 4;
+        _fontGamma = v; 
+        _gamma65.gamma = v;
+        _gamma256.gamma = v;
+    }
+
 	~this() {
 		Log.d("Destroying font manager");
 	}
@@ -688,3 +702,46 @@ struct GlyphCache
 }
 
 
+// support of font glyph Gamma correction
+// table to correct gamma and translate to output range 0..255
+// maxv is 65 for win32 fonts, 256 for freetype
+import std.math;
+//---------------------------------
+struct glyph_gamma_table(int maxv = 65)
+{
+    this(double gammaValue = 1.0)
+    {
+        gamma = gammaValue;
+    }
+    @property double gamma() { return _gamma; }
+    @property void gamma(double g) {
+        _gamma = g;
+        for(int i = 0; i < maxv; i++)
+        {
+            double v = (maxv - 1.0 - i) / maxv;
+            v = pow(v, g);
+            int n = cast(int)round(v * 255);
+            n = 255 - n;
+            if (n < 0)
+                n = 0;
+            else if (n > 255)
+                n = 255;
+            _map[i] = cast(ubyte)n;
+        }
+    }
+    /// correct byte value from source range to 0..255 applying gamma
+    ubyte correct(ubyte src) {
+        if (src >= maxv) src = maxv - 1;
+        return _map[src];
+    }
+private:
+    ubyte _map[maxv];
+    double _gamma = 1.0;
+};
+
+__gshared glyph_gamma_table!65 _gamma65;
+__gshared glyph_gamma_table!256 _gamma256;
+__gshared static this() {
+    _gamma65 = glyph_gamma_table!65(1.0);
+    _gamma256 = glyph_gamma_table!256(1.0);
+}

src/dlangui/graphics/ftfonts.d

@@ -304,7 +304,7 @@ private class FreeTypeFontFile {
                     // antialiased
 					for (uint y = 0; y < h; y++) {
 						for (uint x = 0; x < w; x++) {
-							glyph.glyph[y * w + x] = bitmap.buffer[y * bitmap.pitch + x];
+							glyph.glyph[y * w + x] = _gamma256.correct(bitmap.buffer[y * bitmap.pitch + x]);
 						}
 					}
                 }

src/dlangui/platforms/windows/win32fonts.d

@@ -375,11 +375,7 @@ class Win32Font : Font {
 				        {
 					        for (int x = 0; x < g.blackBoxX; x++)
 					        {
-						        ubyte b = src[x];
+						        dst[x] = _gamma65.correct(src[x]);
-						        if (b>=64)
-							        b = 63;
-						        b = (b<<2) & 0xFC;
-						        dst[x] = b;
 					        }
 					        src += glyph_row_size;
 					        dst += g.blackBoxX;

src/dlangui/widgets/editors.d

@@ -2766,11 +2766,12 @@ class EditBox : EditWidgetBase {
                 return true;
             case EditorActions.ZoomIn:
                 {
-                    if (_minFontSize < _maxFontSize && _minFontSize >= 9 && _maxFontSize >= 9) {
+                    if (_minFontSize < _maxFontSize && _minFontSize >= 7 && _maxFontSize >= 7) {
                         int currentFontSize = fontSize;
-						int increment = currentFontSize >= 30 ? 2 : 1;
+						int increment = currentFontSize >= 40 ? 2 : 1;
                         int newFontSize = currentFontSize + increment; //* 110 / 100;
-                        if (currentFontSize != newFontSize && newFontSize <= _maxFontSize) {
+                        if (currentFontSize != newFontSize && newFontSize <= _maxFontSize && newFontSize >= _minFontSize) {
+                            Log.i("Font size in editor ", id, " zoomed to ", newFontSize);
                             fontSize = cast(ushort)newFontSize;
                             updateFontProps();
                             measureVisibleText();
@@ -2973,11 +2974,11 @@ class LogWidget : EditBox {
         super(ID);
         _scrollLock = true;
         enabled = false;
-        fontSize = 15;
+        fontSize = 14;
 		//fontFace = "Consolas,Lucida Console,Courier New";
 		fontFace = "Consolas,DejaVuSansMono,Lucida Sans Typewriter,Courier New,Lucida Console";
 		fontFamily = FontFamily.MonoSpace;
-        minFontSize(10).maxFontSize(32); // allow font zoom with Ctrl + MouseWheel
+        minFontSize(8).maxFontSize(32); // allow font zoom with Ctrl + MouseWheel
     }
     /// append lines to the end of text
     void appendText(dstring text) {

src/dlangui/widgets/srcedit.d

@@ -28,7 +28,7 @@ class SourceEdit : EditBox {
 		fontFace = "Consolas,DejaVuSansMono,Lucida Sans Typewriter,Courier New,Lucida Console";
 		//fontFace = "Consolas,Lucida Console,Courier New";
 		fontFamily = FontFamily.MonoSpace;
-		fontSize = 17;
+		fontSize = 14;
 		layoutWidth(FILL_PARENT).layoutHeight(FILL_PARENT);
         minFontSize(10).maxFontSize(75); // allow font zoom with Ctrl + MouseWheel
 

views/res/theme_default.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <theme id="theme_default" 
-        fontSize="14" 
+        fontSize="12" 
         fontFace="Verdana,Arial,DejaVu Sans"
         fontFamily="SansSerif"
 	>
@@ -116,6 +116,7 @@
         backgroundImageId="tab_btn_dark_up"
         />
     <style id="TAB_UP_BUTTON_DARK_TEXT"
+        fontSize="10"
         textColor="#E0E0E0"
         align="Center"
         >
@@ -134,6 +135,7 @@
     </style>
     <style id="TAB_UP_BUTTON_TEXT"
         textColor="#000000"
+        fontSize="10"
         align="Center"
         >
         <state state_selected="true" state_focused="true" textColor="#000000"/>
@@ -282,6 +284,7 @@
         layoutWidth="FILL_PARENT"
         layoutHeight="WRAP_CONTENT"
         padding="3,3,3,3"
+	fontSize="12"
         align="Left|VCenter"
         />
     <style id="DOCK_WINDOW_BODY"
@@ -325,7 +328,7 @@
         minHeight="14"
         layoutWidth="FILL_PARENT"
         layoutHeight="WRAP_CONTENT"
-        fontSize="14">
+        >
     </style>
     <style id="TREE_ITEM_EXPAND_ICON"
         margins="0,0,0,0"
@@ -348,7 +351,6 @@
         layoutHeight="WRAP_CONTENT"
         align="Left|VCenter"
         textFlags="Parent"
-	fontSize="14"
     />
     <style id="RESIZER_VERTICAL"
         layoutWidth="FILL_PARENT"