Add Texture YUV example

examples/renderer-yuv.rs

@@ -0,0 +1,72 @@
+extern crate sdl2;
+
+use sdl2::video::{Window, WindowPos, SHOWN};
+use sdl2::render::{RenderDriverIndex, ACCELERATED, Renderer};
+use sdl2::pixels::PixelFormatEnum;
+use sdl2::rect::Rect;
+use sdl2::event::poll_event;
+use sdl2::event::Event::{Quit, KeyDown};
+use sdl2::keycode::KeyCode;
+
+pub fn main() {
+    sdl2::init(sdl2::INIT_VIDEO);
+
+    let window = match Window::new("rust-sdl2 demo: YUV", WindowPos::PosCentered, WindowPos::PosCentered, 800, 600, SHOWN) {
+        Ok(window) => window,
+        Err(err) => panic!("failed to create window: {}", err)
+    };
+
+    let renderer = match Renderer::from_window(window, RenderDriverIndex::Auto, ACCELERATED) {
+        Ok(renderer) => renderer,
+        Err(err) => panic!("failed to create renderer: {}", err)
+    };
+
+    let mut texture = renderer.create_texture_streaming(PixelFormatEnum::IYUV, (256, 256)).unwrap();
+    // Create a U-V gradient
+    texture.with_lock(None, |buffer: &mut [u8], pitch: usize| {
+        // `pitch` is the width of the Y component
+        // The U and V components are half the width and height of Y
+
+        let w = 256;
+        let h = 256;
+
+        // Set Y (constant)
+        for y in 0us..h {
+            for x in 0us..w {
+                let offset = y*pitch + x;
+                buffer[offset] = 128;
+            }
+        }
+
+        let y_size = pitch*h;
+
+        // Set U and V (X and Y)
+        for y in 0us..h/2 {
+            for x in 0us..w/2 {
+                let u_offset = y_size + y*pitch/2 + x;
+                let v_offset = y_size + (pitch/2 * h/2) + y*pitch/2 + x;
+                buffer[u_offset] = (x*2) as u8;
+                buffer[v_offset] = (y*2) as u8;
+            }
+        }
+    }).unwrap();
+
+    let mut drawer = renderer.drawer();
+    drawer.clear();
+    drawer.copy(&texture, None, Some(Rect::new(100, 100, 256, 256)));
+    drawer.present();
+
+    loop {
+        match poll_event() {
+            Quit{..} => break,
+            KeyDown { keycode: key, .. } => {
+                if key == KeyCode::Escape {
+                    break;
+                }
+            }
+            _ => {}
+        }
+    }
+
+    sdl2::quit();
+}