Render the letter J

This letter brought to you by OpenGL and freetype.

6 files changed, 722 insertions, 7 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 6cb37f09..c5bec9f1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,17 +2,117 @@
 name = "alacritty"
 version = "0.1.0"
 dependencies = [
+ "cgmath 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "freetype-rs 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gl 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glutin 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo-fontconfig 0.2.0 (git+https://github.com/jwilm/rust-fontconfig)",
 ]
 
 [[package]]
+name = "android_glue"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "bitflags"
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "byteorder"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cgl"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gleam 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "cgmath"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.18 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "cocoa"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-graphics 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "objc 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "core-foundation"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "core-foundation-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "core-foundation-sys"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "core-graphics"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "core-foundation 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 0.6.14 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "dlib"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libloading 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "dwmapi-sys"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "dylib"
+version = "0.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "expat-sys"
 version = "2.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -42,16 +142,120 @@ dependencies = [
 ]
 
 [[package]]
+name = "fs2"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "kernel32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "gcc"
 version = "0.3.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "gdi32-sys"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "gl"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gl_generator 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "khronos_api 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "gl_generator"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "khronos_api 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "xml-rs 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "gleam"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gl_generator 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "khronos_api 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "glutin"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "android_glue 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cgl 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cocoa 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-graphics 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "dwmapi-sys 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gdi32-sys 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gl_generator 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "kernel32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "khronos_api 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "objc 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "osmesa-sys 0.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "shared_library 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "shell32-sys 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "user32-sys 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-client 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-kbd 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-window 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "x11-dl 2.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "kernel32-sys"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "khronos_api"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "lazy_static"
+version = "0.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "libc"
 version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "libloading"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "kernel32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "libz-sys"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -62,16 +266,91 @@ dependencies = [
 ]
 
 [[package]]
+name = "log"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "make-cmd"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "malloc_buf"
+version = "0.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "memmap"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "fs2 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "kernel32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "num"
+version = "0.1.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.18 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "objc"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "malloc_buf 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "osmesa-sys"
+version = "0.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "shared_library 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "pkg-config"
 version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "rand"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rustc-serialize"
+version = "0.3.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "serde"
+version = "0.6.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "servo-fontconfig"
 version = "0.2.0"
 source = "git+https://github.com/jwilm/rust-fontconfig#419135e5e1106ec0973dd4923bd9c70d8e438cc8"
@@ -90,3 +369,119 @@ dependencies = [
  "pkg-config 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "shared_library"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "shell32-sys"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "tempfile"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "kernel32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "user32-sys"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-client"
+version = "0.5.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-scanner 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-sys 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-kbd"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "dlib 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memmap 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-client 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-scanner"
+version = "0.5.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "xml-rs 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-sys"
+version = "0.5.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "dlib 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-window"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "byteorder 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempfile 1.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-client 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "winapi"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi-build"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "x11-dl"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "dylib 0.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "xml-rs"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
diff --git a/Cargo.toml b/Cargo.toml
index ff4a0a7a..66d5c19b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,3 +7,6 @@ authors = ["Joe Wilm <joe@jwilm.com>"]
 servo-fontconfig = { git = "https://github.com/jwilm/rust-fontconfig" }
 freetype-rs = "0.5.0"
 libc = "*"
+glutin = "*"
+gl = "*"
+cgmath = "0.7"
diff --git a/res/text.f.glsl b/res/text.f.glsl
new file mode 100644
index 00000000..32266b3e
--- /dev/null
+++ b/res/text.f.glsl
@@ -0,0 +1,11 @@
+#version 330 core
+in vec2 TexCoords;
+
+uniform sampler2D text;
+uniform vec3 textColor;
+
+void main()
+{
+    vec4 sampled = vec4(1.0, 1.0, 1.0, texture(text, TexCoords).r);
+    gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0) * sampled;
+}
diff --git a/res/text.v.glsl b/res/text.v.glsl
new file mode 100644
index 00000000..89bded5c
--- /dev/null
+++ b/res/text.v.glsl
@@ -0,0 +1,11 @@
+#version 330 core
+layout (location = 0) in vec4 vertex;
+out vec2 TexCoords;
+
+uniform mat4 projection;
+
+void main()
+{
+    gl_Position = projection * vec4(vertex.xy, 0.0, 1.0);
+    TexCoords = vertex.zw;
+}
diff --git a/src/main.rs b/src/main.rs
index 7356bd36..2ba98473 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,10 +1,305 @@
 extern crate fontconfig;
 extern crate freetype;
 extern crate libc;
+extern crate glutin;
+extern crate gl;
+extern crate cgmath;
 
 mod list_fonts;
 mod text;
 
+
+use std::ffi::CString;
+use std::mem::size_of;
+use std::ptr;
+
+use libc::c_void;
+
+use gl::types::*;
+
+use cgmath::Matrix;
+
+use text::RasterizedGlyph;
+
+static TEXT_SHADER_V: &'static str = include_str!("../res/text.v.glsl");
+static TEXT_SHADER_F: &'static str = include_str!("../res/text.f.glsl");
+
 fn main() {
-    println!("Hello, world!");
+    let window = glutin::Window::new().unwrap();
+    let (width, height) = window.get_inner_size_pixels().unwrap();
+    unsafe {
+        window.make_current()
+    };
+
+    unsafe {
+        gl::load_with(|symbol| window.get_proc_address(symbol) as *const _);
+        gl::Viewport(0, 0, width as i32, height as i32);
+    }
+
+    let rasterizer = text::Rasterizer::new();
+    let glyph_j = rasterizer.get_glyph(180., 'J');
+
+    let tex = AlphaTexture::new(
+        glyph_j.width as i32,
+        glyph_j.height as i32,
+        glyph_j.buf.as_ptr() as *const _
+    );
+
+    unsafe {
+        gl::Enable(gl::BLEND);
+        gl::BlendFunc(gl::SRC_ALPHA, gl::ONE_MINUS_SRC_ALPHA);
+    }
+
+    let mut vao: GLuint = 0;
+    let mut vbo: GLuint = 0;
+    unsafe {
+        gl::GenVertexArrays(1, &mut vao);
+        gl::GenBuffers(1, &mut vbo);
+        gl::BindVertexArray(vao);
+
+        gl::BindBuffer(gl::ARRAY_BUFFER, vbo);
+        gl::BufferData(
+            gl::ARRAY_BUFFER,
+            (size_of::<f32>() * 6 * 4) as GLsizeiptr,
+            ptr::null(),
+            gl::DYNAMIC_DRAW
+        );
+        gl::EnableVertexAttribArray(0);
+        gl::VertexAttribPointer(0, 4, gl::FLOAT, gl::FALSE, 4 * size_of::<f32>() as i32,
+                                ptr::null());
+        gl::BindBuffer(gl::ARRAY_BUFFER, 0);
+        gl::BindVertexArray(0);
+    }
+
+    let program = ShaderProgram::new(width, height);
+
+    for event in window.wait_events() {
+        unsafe {
+            gl::ClearColor(0.08, 0.08, 0.08, 1.0);
+            gl::Clear(gl::COLOR_BUFFER_BIT);
+        }
+
+        render(&program, &glyph_j, &tex, vbo, vao);
+
+        window.swap_buffers();
+
+        match event {
+            glutin::Event::Closed => break,
+            _ => ()
+        }
+    }
+}
+
+/// Render a character
+///
+/// TODO use element array to describe quad instead
+fn render(program: &ShaderProgram, glyph: &RasterizedGlyph, tex: &AlphaTexture, vbo: GLuint,
+          vao: GLuint)
+{
+    program.activate();
+    unsafe {
+        // set color
+        gl::Uniform3f(program.color, 1., 1., 0.5);
+    }
+
+    // bottom left of character
+    let left = 10. as f32;
+    let bottom = 10. as f32;
+
+    // top right of character
+    let top = bottom + glyph.height as f32;
+    let right = left + glyph.width as f32;
+    let vertices: [[f32; 4]; 6] = [
+        [left,    top,     0.,   0.],
+        [left,    bottom,  0.,   1.],
+        [right,   bottom,  1.,   1.],
+
+        [left,    top,     0.,   0.],
+        [right,   bottom,  1.,   1.],
+        [right,   top,     1.,   0.],
+    ];
+
+    unsafe {
+        gl::ActiveTexture(gl::TEXTURE0);
+        gl::BindVertexArray(vao);
+
+        gl::BindTexture(gl::TEXTURE_2D, tex.id);
+        gl::BindBuffer(gl::ARRAY_BUFFER, vbo);
+        gl::BufferSubData(
+            gl::ARRAY_BUFFER,
+            0,
+            (4 * 6 * size_of::<f32>()) as isize,
+            vertices.as_ptr() as *const _
+        );
+        gl::BindBuffer(gl::ARRAY_BUFFER, 0);
+
+
+        gl::DrawArrays(gl::TRIANGLES, 0, 6);
+        gl::BindVertexArray(0);
+        gl::BindTexture(gl::TEXTURE_2D, 0);
+    }
+
+    program.deactivate();
+}
+
+pub struct ShaderProgram {
+    id: GLuint,
+    /// uniform location for projection matrix
+    projection: GLint,
+    /// uniform location foyr textColor
+    color: GLint,
+}
+
+impl ShaderProgram {
+    pub fn activate(&self) {
+        unsafe {
+            gl::UseProgram(self.id);
+        }
+    }
+
+    pub fn deactivate(&self) {
+        unsafe {
+            gl::UseProgram(0);
+        }
+    }
+
+    pub fn new(width: u32, height: u32) -> ShaderProgram {
+        let vertex_shader = ShaderProgram::create_vertex_shader();
+        let fragment_shader = ShaderProgram::create_fragment_shader();
+        let program = ShaderProgram::create_program(vertex_shader, fragment_shader);
+
+        unsafe {
+            gl::DeleteShader(vertex_shader);
+            gl::DeleteShader(fragment_shader);
+        }
+
+        // get uniform locations
+        let projection_str = CString::new("projection").unwrap();
+        let color_str = CString::new("textColor").unwrap();
+
+        let (projection, color) = unsafe {
+            (
+                gl::GetUniformLocation(program, projection_str.as_ptr()),
+                gl::GetUniformLocation(program, color_str.as_ptr())
+            )
+        };
+
+        assert!(projection != gl::INVALID_VALUE as i32);
+        assert!(projection != gl::INVALID_OPERATION as i32);
+        assert!(color != gl::INVALID_VALUE as i32);
+        assert!(color != gl::INVALID_OPERATION as i32);
+
+        let shader = ShaderProgram {
+            id: program,
+            projection: projection,
+            color: color,
+        };
+
+        // set projection uniform
+        let ortho = cgmath::ortho(0., width as f32, 0., height as f32, -1., 1.);
+        let projection: [[f32; 4]; 4] = ortho.into();
+
+        println!("width: {}, height: {}", width, height);
+
+        shader.activate();
+        unsafe {
+            gl::UniformMatrix4fv(shader.projection, 1, gl::FALSE, projection.as_ptr() as *const _);
+        }
+        shader.deactivate();
+
+        shader
+    }
+
+    fn create_program(vertex: GLuint, fragment: GLuint) -> GLuint {
+
+        unsafe {
+            let program = gl::CreateProgram();
+            gl::AttachShader(program, vertex);
+            gl::AttachShader(program, fragment);
+            gl::LinkProgram(program);
+
+            let mut success: GLint = 0;
+            gl::GetProgramiv(program, gl::LINK_STATUS, &mut success);
+
+            if success != (gl::TRUE as GLint) {
+                panic!("failed to link shader program");
+            }
+            program
+        }
+    }
+
+    fn create_fragment_shader() -> GLuint {
+        unsafe {
+            let fragment_shader = gl::CreateShader(gl::FRAGMENT_SHADER);
+            let fragment_source = CString::new(TEXT_SHADER_F).unwrap();
+            gl::ShaderSource(fragment_shader, 1, &fragment_source.as_ptr(), ptr::null());
+            gl::CompileShader(fragment_shader);
+
+            let mut success: GLint = 0;
+            gl::GetShaderiv(fragment_shader, gl::COMPILE_STATUS, &mut success);
+
+            if success != (gl::TRUE as GLint) {
+                panic!("failed to compiler fragment shader");
+            }
+            fragment_shader
+        }
+    }
+
+    fn create_vertex_shader() -> GLuint {
+        unsafe {
+            let vertex_shader = gl::CreateShader(gl::VERTEX_SHADER);
+            let vertex_source = CString::new(TEXT_SHADER_V).unwrap();
+            gl::ShaderSource(vertex_shader, 1, &vertex_source.as_ptr(), ptr::null());
+            gl::CompileShader(vertex_shader);
+
+            let mut success: GLint = 0;
+            gl::GetShaderiv(vertex_shader, gl::COMPILE_STATUS, &mut success);
+
+            if success != (gl::TRUE as GLint) {
+                panic!("failed to compiler vertex shader");
+            }
+            vertex_shader
+        }
+    }
+}
+
+struct AlphaTexture {
+    pub id: GLuint,
+    pub width: i32,
+    pub height: i32,
+}
+
+impl AlphaTexture {
+    pub fn new(width: i32, height: i32, bytes: *const ::std::os::raw::c_void) -> AlphaTexture {
+        let mut id: GLuint = 0;
+        unsafe {
+            gl::PixelStorei(gl::UNPACK_ALIGNMENT, 1);
+            gl::GenTextures(1, &mut id);
+            gl::BindTexture(gl::TEXTURE_2D, id);
+            gl::TexImage2D(
+                gl::TEXTURE_2D,
+                0,
+                gl::RED as i32,
+                width as i32,
+                height as i32,
+                0,
+                gl::RED,
+                gl::UNSIGNED_BYTE,
+                bytes
+            );
+
+            gl::TexParameteri(gl::TEXTURE_2D, gl::TEXTURE_WRAP_S, gl::CLAMP_TO_EDGE as i32);
+            gl::TexParameteri(gl::TEXTURE_2D, gl::TEXTURE_WRAP_T, gl::CLAMP_TO_EDGE as i32);
+            gl::TexParameteri(gl::TEXTURE_2D, gl::TEXTURE_MIN_FILTER, gl::LINEAR as i32);
+            gl::TexParameteri(gl::TEXTURE_2D, gl::TEXTURE_MAG_FILTER, gl::LINEAR as i32);
+
+            gl::BindTexture(gl::TEXTURE_2D, 0);
+        }
+
+        AlphaTexture {
+            id: id,
+            width: width,
+            height: height,
+        }
+    }
 }
diff --git a/src/text.rs b/src/text.rs
index 5694e2ce..14a0cfb7 100644
--- a/src/text.rs
+++ b/src/text.rs
@@ -49,12 +49,12 @@ impl Rasterizer {
 }
 
 #[derive(Debug)]
-struct RasterizedGlyph {
-    width: usize,
-    height: usize,
-    top: usize,
-    left: usize,
-    buf: Vec<u8>,
+pub struct RasterizedGlyph {
+    pub width: usize,
+    pub height: usize,
+    pub top: usize,
+    pub left: usize,
+    pub buf: Vec<u8>,
 }