Initial commit

renderer/font.jai

@@ -0,0 +1,105 @@
+Font_Handle :: #type, distinct u32;
+
+Glyph :: struct {
+    ax: float; // advance.x
+    ay: float; // advance.y
+    bw: float; // bitmap.width;
+    bh: float; // bitmap.rows;
+    bl: float; // bitmap_left;
+    bt: float; // bitmap_top;
+    tx: float; // x offset of glyph in texture coordinates
+}
+
+Point :: struct {
+    x: float;
+    y: float;
+    s: float;
+    t: float;
+
+    color: Vector4;
+};
+
+Font :: struct {
+    glyphs: [..] Glyph;
+    face: FT_Face;
+    pixel_size: u32;
+    atlas_width: u32;
+    atlas_height: u32;
+    texture: Texture_Handle;
+}
+
+ft : FT_Library;
+
+init_freetype :: () {
+    if FT_Init_FreeType(*ft) {
+        log("Couldn't init Freetype\n");
+    }
+
+}
+
+create_font :: (renderer: *Renderer, path: string, pixel_size: u32) -> Font_Handle {
+    font: Font;
+    font.pixel_size = pixel_size;
+    array_resize(*font.glyphs, 128);
+
+    if FT_New_Face(ft, path.data, 0, *font.face) {
+        log("Couldn't create new face\n");
+        assert(false);
+    } else {
+        FT_Set_Pixel_Sizes(font.face, 0, pixel_size);
+
+        g := font.face.glyph;
+        w : u32 = 0;
+        h : u32 = 0;
+
+        index := 0;
+        for 32..128-1 {
+            if FT_Load_Char(font.face, xx it, FT_LOAD_RENDER) {
+                continue;
+            }
+
+            w += g.bitmap.width + 1;
+            h = max(h, g.bitmap.rows);
+        }
+
+        atlas_width := w;
+
+        bytes : [..] u8;
+        bytes.allocator = temp;
+        array_resize(*bytes, w * h);
+
+        texture := create_texture(renderer, bytes.data, w, h, 1, generate_mips=false, format=.R8_UNORM);
+
+        font.atlas_width = w;
+        font.atlas_height = h;
+
+        font.texture = texture;
+
+        x : u32 = 0;
+
+        pixel_width := 1.0 / cast(float)atlas_width;
+
+        for 32..128-1 {
+            if FT_Load_Char(font.face, xx it, FT_LOAD_RENDER) continue;
+
+            // @Speed: We should put this buffer data into an array and upload everything once after this loop
+            update_texture_region(renderer, texture, x, 0, g.bitmap.width, g.bitmap.rows, 1, g.bitmap.buffer);
+
+            font.glyphs[it].ax = cast(float)(g.advance.x >> 6);
+            font.glyphs[it].ay = cast(float)(g.advance.y >> 6);
+            font.glyphs[it].bw = cast(float)g.bitmap.width;
+            font.glyphs[it].bh = cast(float)g.bitmap.rows;
+            font.glyphs[it].bl = cast(float)g.bitmap_left;
+            font.glyphs[it].bt = cast(float)g.bitmap_top;
+            font.glyphs[it].tx = cast(float)x / cast(float)w;
+            x += g.bitmap.width + 1;
+        }
+
+        array_add(*renderer.fonts, font);
+        return xx renderer.fonts.count;
+    }
+
+    return 0;
+}
+
+#import "freetype-2.12.1";