autocommit 2022-01-28 19:46:23 CET

src/render/egl/context.rs

@@ -0,0 +1,72 @@
+use crate::render::egl::display::EglDisplay;
+use crate::render::egl::sys::{
+    eglDestroyContext, eglMakeCurrent, EGLContext, EGLSurface, EGL_FALSE, EGL_TRUE,
+};
+use crate::render::ext::GlExt;
+use crate::render::gl::sys::{GLint, GLuint};
+use crate::render::RenderError;
+use std::rc::Rc;
+
+#[derive(Debug, Clone)]
+pub struct EglContext {
+    pub dpy: Rc<EglDisplay>,
+    pub ext: GlExt,
+    pub ctx: EGLContext,
+
+    pub tex_prog: GLuint,
+    pub tex_tex: GLint,
+    pub tex_texcoord: GLint,
+    pub tex_pos: GLint,
+}
+
+impl Drop for EglContext {
+    fn drop(&mut self) {
+        unsafe {
+            if eglDestroyContext(self.dpy.dpy, self.ctx) != EGL_TRUE {
+                log::warn!("`eglDestroyContext` failed");
+            }
+        }
+    }
+}
+
+#[thread_local]
+static mut CURRENT: EGLContext = EGLContext::none();
+
+impl EglContext {
+    #[inline]
+    pub fn with_current<T, F: FnOnce() -> Result<T, RenderError>>(
+        &self,
+        f: F,
+    ) -> Result<T, RenderError> {
+        unsafe {
+            if CURRENT == self.ctx {
+                return f();
+            }
+            self.with_current_slow(f)
+        }
+    }
+
+    #[cold]
+    unsafe fn with_current_slow<T, F: FnOnce() -> Result<T, RenderError>>(
+        &self,
+        f: F,
+    ) -> Result<T, RenderError> {
+        if eglMakeCurrent(
+            self.dpy.dpy,
+            EGLSurface::none(),
+            EGLSurface::none(),
+            self.ctx,
+        ) == EGL_FALSE
+        {
+            return Err(RenderError::MakeCurrent);
+        }
+        let prev = CURRENT;
+        CURRENT = self.ctx;
+        let res = f();
+        if eglMakeCurrent(self.dpy.dpy, EGLSurface::none(), EGLSurface::none(), prev) == EGL_FALSE {
+            panic!("Could not restore EGLContext");
+        }
+        CURRENT = prev;
+        res
+    }
+}