# HG changeset patch
# User Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
# Date 1579371591 -3600
# Node ID 0ebf6467e4ffb66abee76bc3525f43261f3fb388
# Parent  90e907859bae1b37fbe5c110b9c709600ffbebe3
examples: Add a menu example.

diff --git a/Cargo.toml b/Cargo.toml
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@ license = "GPL-3.0-or-later"
 [dependencies]
 nom = "5"
 encoding_rs = "0.8"
-image = { version = "0.22", default-features = false, features = ["png_codec"] }
+image = { version = "0.22", default-features = false, features = ["png_codec", "jpeg"] }
 bitflags = "1"
 luminance = "0.38"
 luminance-glfw = { version = "0.12", default-features = false, features = ["log-errors"] }
diff --git a/examples/common.rs b/examples/common.rs
--- a/examples/common.rs
+++ b/examples/common.rs
@@ -45,8 +45,11 @@ fn merge_rgb_alpha(rgb: &DynamicImage, a
         .collect::<Vec<_>>()
 }
 
-fn load_rgb_png(surface: &mut GlfwSurface, path: &Path) -> Result<LoadedTexture, TextureLoadError> {
-    let img = open_rgb_png(&path)?;
+pub fn load_from_data(data: &[u8]) -> Result<DynamicImage, ImageError> {
+    image::load_from_memory(data)
+}
+
+pub fn upload_texture_from_rgb_image(surface: &mut GlfwSurface, img: DynamicImage) -> Result<LoadedTexture, TextureLoadError> {
     let (width, height) = img.dimensions();
     let texels = img
         .pixels()
@@ -65,6 +68,11 @@ fn load_rgb_png(surface: &mut GlfwSurfac
     Ok(LoadedTexture::Rgb(tex))
 }
 
+pub fn load_rgb_texture(surface: &mut GlfwSurface, path: &Path) -> Result<LoadedTexture, TextureLoadError> {
+    let img = open_rgb_png(&path)?;
+    upload_texture_from_rgb_image(surface, img)
+}
+
 fn load_rgb_a_pngs(surface: &mut GlfwSurface, rgb: &Path, alpha: &Path) -> Result<LoadedTexture, TextureLoadError> {
     let img = open_alpha_png(&alpha)?;
     let alpha = match img.grayscale() {
@@ -99,7 +107,7 @@ pub fn load_anm_image<P: AsRef<Path>>(mu
             load_rgb_a_pngs(&mut surface, &png_filename, &alpha_filename)
         },
         None => {
-            load_rgb_png(&mut surface, &png_filename)
+            load_rgb_texture(&mut surface, &png_filename)
         }
     }
 }
diff --git a/examples/menu.rs b/examples/menu.rs
new file mode 100644
--- /dev/null
+++ b/examples/menu.rs
@@ -0,0 +1,182 @@
+use luminance::blending::{Equation, Factor};
+use luminance::context::GraphicsContext;
+use luminance::pipeline::{BoundTexture, PipelineState};
+use luminance::pixel::NormUnsigned;
+use luminance::render_state::RenderState;
+use luminance::shader::program::{Program, Uniform};
+use luminance::tess::{Mode, TessBuilder};
+use luminance::texture::{Dim2, Flat};
+use luminance_derive::{Semantics, Vertex, UniformInterface};
+use luminance_glfw::{Action, Key, WindowEvent, GlfwSurface, Surface, WindowDim, WindowOpt};
+use touhou::th06::pbg3;
+use touhou::th06::anm0::Anm0;
+use touhou::th06::anm0_vm::{AnmRunner, Sprite, Vertex as FakeVertex};
+use touhou::util::math::{perspective, setup_camera, ortho_2d};
+use touhou::util::prng::Prng;
+use std::cell::RefCell;
+use std::rc::Rc;
+use std::env;
+use std::path::Path;
+
+#[path = "common.rs"]
+mod common;
+use common::LoadedTexture;
+
+const VS: &str = r#"
+in ivec3 in_position;
+in vec2 in_texcoord;
+in vec4 in_color;
+
+uniform mat4 mvp;
+
+out vec2 texcoord;
+out vec4 color;
+
+void main()
+{
+    gl_Position = mvp * vec4(vec3(in_position), 1.0);
+    texcoord = vec2(in_texcoord);
+
+    // It’s already normalized from the u8 being passed.
+    color = in_color;
+}
+"#;
+
+const FS: &str = r#"
+in vec2 texcoord;
+in vec4 color;
+
+uniform sampler2D color_map;
+
+out vec4 frag_color;
+
+void main()
+{
+    frag_color = texture(color_map, texcoord) * color;
+}
+"#;
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Semantics)]
+pub enum Semantics {
+    #[sem(name = "in_position", repr = "[i16; 3]", wrapper = "VertexPosition")]
+    Position,
+
+    #[sem(name = "in_texcoord", repr = "[f32; 2]", wrapper = "VertexTexcoord")]
+    Texcoord,
+
+    #[sem(name = "in_color", repr = "[u8; 4]", wrapper = "VertexColor")]
+    Color,
+}
+
+#[repr(C)]
+#[derive(Clone, Copy, Debug, PartialEq, Vertex)]
+#[vertex(sem = "Semantics")]
+struct Vertex {
+    pos: VertexPosition,
+    uv: VertexTexcoord,
+    #[vertex(normalized = "true")]
+    rgba: VertexColor,
+}
+
+#[derive(UniformInterface)]
+struct ShaderInterface {
+    // the 'static lifetime acts as “anything” here
+    color_map: Uniform<&'static BoundTexture<'static, Flat, Dim2, NormUnsigned>>,
+
+    #[uniform(name = "mvp")]
+    mvp: Uniform<[[f32; 4]; 4]>,
+}
+
+const DEFAULT_VERTICES: [Vertex; 4] = [
+    Vertex::new(VertexPosition::new([0, 0, 0]), VertexTexcoord::new([0., 0.]), VertexColor::new([255, 255, 255, 255])),
+    Vertex::new(VertexPosition::new([640, 0, 0]), VertexTexcoord::new([1., 0.]), VertexColor::new([255, 255, 255, 255])),
+    Vertex::new(VertexPosition::new([640, 480, 0]), VertexTexcoord::new([1., 1.]), VertexColor::new([255, 255, 255, 255])),
+    Vertex::new(VertexPosition::new([0, 480, 0]), VertexTexcoord::new([0., 1.]), VertexColor::new([255, 255, 255, 255])),
+];
+
+fn main() {
+    // Parse arguments.
+    let args: Vec<_> = env::args().collect();
+    if args.len() != 2 {
+        eprintln!("Usage: {} <unarchived directory>", args[0]);
+        return;
+    }
+    let directory = Path::new(&args[1]);
+
+    let in_dat = directory.join("IN.DAT");
+    // Since GLFW can be slow to create its window, let’s decode the splash screen in another
+    // thread in the meantime.
+    let jpeg_thread = std::thread::spawn(|| {
+        let mut in_pbg3 = pbg3::from_path_buffered(in_dat).expect("IN.DAT present");
+        let jpeg = in_pbg3.get_file("th06logo.jpg", true).expect("th06logo.jpg in IN.DAT");
+        let image = common::load_from_data(&jpeg).expect("th06logo.jpg decodable");
+        image
+    });
+
+    let mut surface = GlfwSurface::new(WindowDim::Windowed(640, 480), "Touhou", WindowOpt::default()).expect("GLFW window");
+
+    let image = jpeg_thread.join().expect("image loading");
+    let tex = common::upload_texture_from_rgb_image(&mut surface, image).expect("image loading");
+
+    // set the uniform interface to our type so that we can read textures from the shader
+    let program =
+        Program::<Semantics, (), ShaderInterface>::from_strings(None, VS, None, FS).expect("program creation").ignore_warnings();
+
+    let mut tess = TessBuilder::new(&mut surface)
+        .add_vertices(DEFAULT_VERTICES)
+        .set_mode(Mode::TriangleFan)
+        .build()
+        .unwrap();
+
+    let mut back_buffer = surface.back_buffer().unwrap();
+    let mut resize = false;
+
+    'app: loop {
+        for event in surface.poll_events() {
+            match event {
+                WindowEvent::Close | WindowEvent::Key(Key::Escape, _, Action::Release, _) => break 'app,
+
+                WindowEvent::FramebufferSize(..) => {
+                    resize = true;
+                }
+
+                _ => (),
+            }
+        }
+
+        if resize {
+            back_buffer = surface.back_buffer().unwrap();
+            resize = false;
+        }
+
+        // here, we need to bind the pipeline variable; it will enable us to bind the texture to the GPU
+        // and use it in the shader
+        surface
+            .pipeline_builder()
+            .pipeline(&back_buffer, &PipelineState::default(), |pipeline, mut shd_gate| {
+                // bind our fancy texture to the GPU: it gives us a bound texture we can use with the shader
+                let bound_tex = match &tex {
+                    LoadedTexture::Rgb(tex) => pipeline.bind_texture(tex),
+                    LoadedTexture::Rgba(tex) => pipeline.bind_texture(tex),
+                };
+
+                shd_gate.shade(&program, |iface, mut rdr_gate| {
+                    // update the texture; strictly speaking, this update doesn’t do much: it just tells the GPU
+                    // to use the texture passed as argument (no allocation or copy is performed)
+                    iface.color_map.update(&bound_tex);
+                    let mvp = ortho_2d(0., 640., 480., 0.);
+                    // TODO: check how to pass by reference.
+                    iface.mvp.update(*mvp.borrow_inner());
+
+                    let render_state = RenderState::default()
+                        .set_blending((Equation::Additive, Factor::SrcAlpha, Factor::SrcAlphaComplement));
+
+                    rdr_gate.render(&render_state, |mut tess_gate| {
+                        tess_gate.render(&tess);
+                    });
+                });
+            });
+
+        surface.swap_buffers();
+    }
+}
diff --git a/src/th06/pbg3.rs b/src/th06/pbg3.rs
--- a/src/th06/pbg3.rs
+++ b/src/th06/pbg3.rs
@@ -8,8 +8,10 @@
 
 use crate::util::bitstream::BitStream;
 use crate::util::lzss;
+use std::fs::File;
 use std::io;
 use std::collections::hash_map::{self, HashMap};
+use std::path::Path;
 
 /// Helper struct to handle strings and integers in PBG3 bitstreams.
 pub struct PBG3BitStream<R: io::Read + io::Seek> {
@@ -132,9 +134,9 @@ impl<R: io::Read + io::Seek> PBG3<R> {
     }
 
     /// Read a single file from this PBG3 archive.
-    pub fn get_file(&mut self, filename: String, check: bool) -> io::Result<Vec<u8>> {
+    pub fn get_file(&mut self, filename: &str, check: bool) -> io::Result<Vec<u8>> {
         // XXX: no unwrap!
-        let (_unknown_1, _unknown_2, checksum, offset, size) = self.entries.get(&filename).unwrap();
+        let (_unknown_1, _unknown_2, checksum, offset, size) = self.entries.get(filename).unwrap();
         self.bitstream.seek(io::SeekFrom::Start(*offset as u64))?;
         let data = lzss::decompress(&mut self.bitstream.bitstream, *size as usize, 0x2000, 13, 4, 3)?;
         if check {
@@ -154,6 +156,13 @@ impl<R: io::Read + io::Seek> PBG3<R> {
     }
 }
 
+/// Open a PBG3 archive from its path.
+pub fn from_path_buffered<P: AsRef<Path>>(path: P) -> io::Result<PBG3<io::BufReader<File>>> {
+    let file = File::open(path)?;
+    let buf_file = io::BufReader::new(file);
+    PBG3::from_file(buf_file)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;