Add freetype support

buildSrc/src/main/groovy/imgui/generate/GenerateLibs.groovy

@@ -24,6 +24,7 @@ class GenerateLibs extends DefaultTask {
         // Copy ImGui h/cpp files
         project.copy { CopySpec spec ->
             spec.from(project.rootProject.file('imgui')) { CopySpec it -> it.include('*.h', '*.cpp') }
+            spec.from(project.rootProject.file('imgui/misc/freetype')) { CopySpec it -> it.include('*.h', '*.cpp') }
             spec.from(project.rootProject.file('imgui-binding/src/main/native'))
             spec.into(jniDir)
         }
@@ -37,6 +38,17 @@ class GenerateLibs extends DefaultTask {
         def linux32 = BuildTarget.newDefaultTarget(BuildTarget.TargetOs.Linux, false)
         def linux64 = BuildTarget.newDefaultTarget(BuildTarget.TargetOs.Linux, true)
 
+        // Freetype Deps Config
+        win32.cppFlags += " -fstack-protector -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include"
+        win32.libraries += "-lfreetype -lbz2 -lssp"
+        win64.cppFlags += " -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include"
+        win64.libraries += "-lfreetype -lbz2 -lssp"
+        linux32.cppFlags += " -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include"
+        linux32.linkerFlags += " -lfreetype"
+        linux64.cppFlags += " -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include"
+        linux64.linkerFlags += " -lfreetype"
+        // End
+
         new AntScriptGenerator().generate(buildConfig, win32, win64, linux32, linux64)
 
         // Generate native libraries

imgui-binding/src/main/java/imgui/ImGuiFreeType.java

@@ -0,0 +1,74 @@
+package imgui;
+
+/**
+ * Read: https://raw.githubusercontent.com/ocornut/imgui/v1.76/misc/freetype/README.md
+ */
+public final class ImGuiFreeType {
+    private ImGuiFreeType() {
+    }
+
+    /*JNI
+        #include <imgui.h>
+        #include <imgui_freetype.h>
+     */
+
+    public static void buildFontAtlas(final ImFontAtlas atlas) {
+        nBuildFontAtlas(atlas.ptr, 0);
+    }
+
+    public static void buildFontAtlas(final ImFontAtlas atlas, int extraFlags) {
+        nBuildFontAtlas(atlas.ptr, extraFlags);
+    }
+
+    private static native void nBuildFontAtlas(long atlasPtr, int extraFlags); /*
+        ImGuiFreeType::BuildFontAtlas((ImFontAtlas*)atlasPtr, (unsigned int)extraFlags);
+    */
+
+    /**
+     * Hinting greatly impacts visuals (and glyph sizes).
+     * When disabled, FreeType generates blurrier glyphs, more or less matches the stb's output.
+     * The Default hinting mode usually looks good, but may distort glyphs in an unusual way.
+     * The Light hinting mode generates fuzzier glyphs but better matches Microsoft's rasterizer.
+     * <p>
+     * You can set those flags on a per font basis in ImFontConfig::RasterizerFlags.
+     * Use the 'extra_flags' parameter of BuildFontAtlas() to force a flag on all your fonts.
+     */
+    public static final class RasterizerFlags {
+        /**
+         * By default, hinting is enabled and the font's native hinter is preferred over the auto-hinter.
+         * Disable hinting. This generally generates 'blurrier' bitmap glyphs when the glyph are rendered in any of the anti-aliased modes.
+         */
+        public static final int NoHinting = 1;
+        /**
+         * Disable auto-hinter.
+         */
+        public static final int NoAutoHint = 1 << 1;
+        /**
+         * Indicates that the auto-hinter is preferred over the font's native hinter.
+         */
+        public static final int ForceAutoHint = 1 << 2;
+        /**
+         * A lighter hinting algorithm for gray-level modes. Many generated glyphs are fuzzier but better resemble their original shape.
+         * This is achieved by snapping glyphs to the pixel grid only vertically (Y-axis),
+         * as is done by Microsoft's ClearType and Adobe's proprietary font renderer.
+         * This preserves inter-glyph spacing in horizontal text.
+         */
+        public static final int LightHinting = 1 << 3;
+        /**
+         * Strong hinting algorithm that should only be used for monochrome output.
+         */
+        public static final int MonoHinting = 1 << 4;
+        /**
+         * Styling: Should we artificially embolden the font?
+         */
+        public static final int Bold = 1 << 5;
+        /**
+         * Styling: Should we slant the font, emulating italic style?
+         */
+        public static final int Oblique = 1 << 6;
+        /**
+         * Disable anti-aliasing. Combine this with MonoHinting for best results!
+         */
+        public static final int Monochrome = 1 << 7;
+    }
+}

imgui-lwjgl3/src/test/java/ImGuiGlfwExample.java

@@ -1,6 +1,7 @@
 import imgui.ImFontAtlas;
 import imgui.ImFontConfig;
 import imgui.ImGui;
+import imgui.ImGuiFreeType;
 import imgui.ImGuiIO;
 import imgui.callbacks.ImStrConsumer;
 import imgui.callbacks.ImStrSupplier;
@@ -262,7 +263,7 @@ public final class ImGuiGlfwExample {
         // ------------------------------
         // Fonts from file/memory example
 
-        fontConfig.setRasterizerMultiply(1.2f); // This will make fonts a bit more readable
+//        fontConfig.setRasterizerMultiply(1.2f); // This will make fonts a bit more readable
 
         // We can add new fonts directly from file
         fontAtlas.addFontFromFileTTF("src/test/resources/DroidSans.ttf", 13, fontConfig);
@@ -276,6 +277,8 @@ public final class ImGuiGlfwExample {
 
         fontConfig.destroy(); // After all fonts were added we don't need this config more
 
+        ImGuiFreeType.buildFontAtlas(fontAtlas, ImGuiFreeType.RasterizerFlags.LightHinting);
+
         // Method initializes LWJGL3 renderer.
         // This method SHOULD be called after you've initialized your ImGui configuration (fonts and so on).
         // ImGui context should be created as well.