1 files changed, 298 insertions, 0 deletions
diff --git a/gfx/wr/wr_glyph_rasterizer/examples/common/boilerplate.rs b/gfx/wr/wr_glyph_rasterizer/examples/common/boilerplate.rs
new file mode 100644
index 0000000000..9590f92b4c
--- /dev/null
+++ b/gfx/wr/wr_glyph_rasterizer/examples/common/boilerplate.rs
@@ -0,0 +1,298 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use api::ImageFormat;
+use euclid::{Transform3D, UnknownUnit};
+use glutin::{self, PossiblyCurrent};
+use gleam::gl;
+use wr_glyph_rasterizer::{RasterizedGlyph, GlyphFormat};
+
+use std::{ffi::CStr, rc::Rc};
+
+#[allow(unused)]
+pub struct Gl {
+    pub gl: Rc<dyn gl::Gl>,
+    program: gl::GLuint,
+    vb: gl::GLuint,
+    vao: gl::GLuint,
+    vs: gl::GLuint,
+    fs: gl::GLuint,
+    textures: Vec<gl::GLuint>,
+    u_transform: i32,
+    u_text_color: i32,
+    u_sampler_color: i32,
+    glyphs: Vec<RasterizedGlyph>,
+}
+
+pub fn load(gl_context: &glutin::Context<PossiblyCurrent>, glyphs: Vec<RasterizedGlyph>) -> Gl {
+    env_logger::init();
+
+    #[cfg(target_os = "macos")]
+    {
+        use core_foundation::{self as cf, base::TCFType};
+        let i = cf::bundle::CFBundle::main_bundle().info_dictionary();
+        let mut i = unsafe { i.to_mutable() };
+        i.set(
+            cf::string::CFString::new("NSSupportsAutomaticGraphicsSwitching"),
+            cf::boolean::CFBoolean::true_value().into_CFType(),
+        );
+    }
+
+    let gl = match gl_context.get_api() {
+        glutin::Api::OpenGl => unsafe {
+            gl::GlFns::load_with(|symbol| gl_context.get_proc_address(symbol) as *const _)
+        },
+        glutin::Api::OpenGlEs => unsafe {
+            gl::GlesFns::load_with(|symbol| gl_context.get_proc_address(symbol) as *const _)
+        },
+        glutin::Api::WebGl => unimplemented!(),
+    };
+
+    let version = unsafe {
+        let data = CStr::from_ptr(gl.get_string(gl::VERSION).as_ptr() as *const _)
+            .to_bytes()
+            .to_vec();
+        String::from_utf8(data).unwrap()
+    };
+
+    println!("OpenGL version {}", version);
+
+    let vs = gl.create_shader(gl::VERTEX_SHADER);
+    gl.shader_source(vs, &[VS_SRC]);
+    gl.compile_shader(vs);
+
+    let fs = gl.create_shader(gl::FRAGMENT_SHADER);
+    gl.shader_source(fs, &[FS_SRC]);
+    gl.compile_shader(fs);
+
+    let program = gl.create_program();
+    gl.attach_shader(program, vs);
+    gl.attach_shader(program, fs);
+    gl.link_program(program);
+    gl.use_program(program);
+
+    let vb = gl.gen_buffers(1)[0];
+    gl.bind_buffer(gl::ARRAY_BUFFER, vb);
+    gl.buffer_data_untyped(
+        gl::ARRAY_BUFFER,
+        (6 * 4 * std::mem::size_of::<f32>()) as gl::types::GLsizeiptr,
+        std::ptr::null(),
+        gl::DYNAMIC_DRAW,
+    );
+
+    let vao = gl.gen_vertex_arrays(1)[0];
+    gl.bind_vertex_array(vao);
+
+    let u_transform = gl.get_uniform_location(program, "uTransform");
+    let u_text_color = gl.get_uniform_location(program, "uTextColor");
+    let u_sampler_color = gl.get_uniform_location(program, "uSamplerColor");
+    let i_position = gl.get_attrib_location(program, "iPosition");
+    let i_tex_coords = gl.get_attrib_location(program, "iTexCoords");
+    gl.vertex_attrib_pointer(
+        i_position as gl::types::GLuint,
+        2,
+        gl::FLOAT,
+        false,
+        4 * std::mem::size_of::<f32>() as gl::types::GLsizei,
+        0,
+    );
+    gl.vertex_attrib_pointer(
+        i_tex_coords as gl::types::GLuint,
+        2,
+        gl::FLOAT,
+        false,
+        4 * std::mem::size_of::<f32>() as gl::types::GLsizei,
+        (2 * std::mem::size_of::<f32>()) as gl::types::GLuint,
+    );
+    gl.enable_vertex_attrib_array(i_position as gl::types::GLuint);
+    gl.enable_vertex_attrib_array(i_tex_coords as gl::types::GLuint);
+
+    let textures = create_texture(&gl, &glyphs);
+
+    gl.bind_buffer(gl::ARRAY_BUFFER, 0);
+    gl.bind_vertex_array(0);
+
+    unsafe { log_shader(&gl, vs) };
+    unsafe { log_shader(&gl, fs) };
+
+    Gl {
+        gl,
+        program,
+        vb,
+        vao,
+        u_transform,
+        u_text_color,
+        u_sampler_color,
+        glyphs,
+        textures,
+        vs,
+        fs,
+    }
+}
+
+fn create_texture(gl: &Rc<dyn gl::Gl>, glyphs: &[RasterizedGlyph]) -> Vec<gl::GLuint> {
+    let textures = gl.gen_textures(glyphs.len() as gl::types::GLsizei);
+    for (i, glyph) in glyphs.iter().enumerate() {
+        let (internal_format, external_format) = get_texture_format(&glyph.format);
+        let texture = textures[i];
+        gl.bind_texture(gl::TEXTURE_2D, texture);
+        gl.tex_parameter_i(
+            gl::TEXTURE_2D,
+            gl::TEXTURE_MAG_FILTER,
+            gl::LINEAR as gl::GLint,
+        );
+        gl.tex_parameter_i(
+            gl::TEXTURE_2D,
+            gl::TEXTURE_MIN_FILTER,
+            gl::LINEAR as gl::GLint,
+        );
+        gl.tex_parameter_i(
+            gl::TEXTURE_2D,
+            gl::TEXTURE_WRAP_S,
+            gl::CLAMP_TO_EDGE as gl::GLint,
+        );
+        gl.tex_parameter_i(
+            gl::TEXTURE_2D,
+            gl::TEXTURE_WRAP_T,
+            gl::CLAMP_TO_EDGE as gl::GLint,
+        );
+        // TODO: use tex_storage_2d
+        gl.tex_image_2d(
+            gl::TEXTURE_2D,
+            0,
+            internal_format as gl::GLint,
+            glyph.width,
+            glyph.height,
+            0,
+            external_format,
+            gl::UNSIGNED_BYTE,
+            Some(&glyph.bytes),
+        );
+
+        gl.pixel_store_i(gl::UNPACK_ALIGNMENT, 1);
+        gl.enable(gl::BLEND);
+        gl.blend_func(gl::SRC_ALPHA, gl::ONE_MINUS_SRC_ALPHA);
+    }
+
+    textures
+}
+
+fn get_texture_format(format: &GlyphFormat) -> (gl::GLuint, gl::GLuint) {
+    match format.image_format(false) {
+        ImageFormat::BGRA8 => (gl::RGBA, gl::BGRA),
+        _ => unimplemented!(),
+    }
+}
+
+unsafe fn log_shader(gl: &Rc<dyn gl::Gl>, shader: gl::GLuint) {
+    let log = gl.get_shader_info_log(shader);
+    if log.len() != 0 {
+        println!("[ERROR] {}", log);
+    }
+}
+
+impl Gl {
+    pub fn draw_frame(
+        &self,
+        width: f32,
+        height: f32,
+        text_color: [f32; 4],
+        background_color: [f32; 4],
+        scale_factor: f32,
+    ) {
+        let projection: Transform3D<f32, UnknownUnit, UnknownUnit> =
+            Transform3D::ortho(0., width, height, 0., -1., 1.);
+        self.gl
+            .uniform_matrix_4fv(self.u_transform, false, &projection.to_array());
+        self.gl.uniform_4fv(self.u_text_color, &text_color);
+
+        self.gl.active_texture(gl::TEXTURE0);
+
+        self.gl.bind_vertex_array(self.vao);
+
+        self.gl.clear_color(
+            background_color[0],
+            background_color[1],
+            background_color[2],
+            background_color[3],
+        );
+        self.gl.clear(gl::COLOR_BUFFER_BIT);
+
+        let mut ax = 0.;
+        for (i, glyph) in self.glyphs.iter().enumerate() {
+            let texture = self.textures[i];
+
+            let x = ax + glyph.left;
+            let y = glyph.top;
+
+            let w = (glyph.width as f32) * scale_factor;
+            let h = (glyph.height as f32) * scale_factor;
+
+            #[rustfmt::skip]
+            let vertices = [
+                x,     y,      0.0, 0.0,
+                x,     y + h,  0.0, 1.0,
+                x + w, y + h,  1.0, 1.0,
+
+                x,     y,      0.0, 0.0,
+                x + w, y + h,  1.0, 1.0,
+                x + w, y,      1.0, 0.0
+            ];
+
+            self.gl.uniform_1i(self.u_sampler_color, 0);
+            self.gl.bind_texture(gl::TEXTURE_2D, texture);
+            self.gl.bind_buffer(gl::ARRAY_BUFFER, self.vb);
+            self.gl.buffer_data_untyped(
+                gl::ARRAY_BUFFER,
+                (vertices.len() * std::mem::size_of::<f32>()) as gl::GLsizeiptr,
+                vertices.as_ptr() as *const _,
+                gl::DYNAMIC_DRAW,
+            );
+            self.gl.bind_buffer(gl::ARRAY_BUFFER, 0);
+
+            self.gl.draw_arrays(gl::TRIANGLES, 0, 6);
+
+            ax += (glyph.left * scale_factor) + (glyph.width as f32 * scale_factor);
+        }
+        self.gl.bind_vertex_array(0);
+        self.gl.bind_texture(gl::TEXTURE_2D, 0);
+
+        unsafe {
+            log_shader(&self.gl, self.vs);
+            log_shader(&self.gl, self.fs);
+        };
+    }
+}
+
+const VS_SRC: &[u8] = b"
+#version 150
+
+in vec2 iPosition;
+in vec2 iTexCoords;
+
+uniform mat4 uTransform;
+
+out vec2 vColorTexCoord;
+
+void main() {
+    gl_Position = uTransform * vec4(iPosition, 0.0, 1.0);
+    vColorTexCoord = iTexCoords;
+}
+\0";
+
+const FS_SRC: &[u8] = b"
+#version 150
+
+in vec2 vColorTexCoord;
+
+uniform sampler2D uSamplerColor;
+uniform vec4 uTextColor;
+
+out vec4 oFragmentColor;
+
+void main() {
+    vec4 alpha = vec4(1.0, 1.0, 1.0, texture(uSamplerColor, vColorTexCoord).r);
+    oFragmentColor = uTextColor * alpha;
+}
+\0";