Add freetype support

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;
+    }
+}