render: support shm screencopy from direct scanout

src/gfx_apis/gl/gl/render_buffer.rs

@@ -1,25 +1,53 @@
 use {
-    crate::gfx_apis::gl::{
-        egl::{context::EglContext, image::EglImage},
-        gl::{
-            frame_buffer::GlFrameBuffer,
-            sys::{
-                GLeglImageOES, GLuint, GL_COLOR_ATTACHMENT0, GL_FRAMEBUFFER,
-                GL_FRAMEBUFFER_COMPLETE, GL_RENDERBUFFER,
+    crate::{
+        format::Format,
+        gfx_apis::gl::{
+            egl::{context::EglContext, image::EglImage},
+            gl::{
+                frame_buffer::GlFrameBuffer,
+                sys::{
+                    GLeglImageOES, GLuint, GL_COLOR_ATTACHMENT0, GL_FRAMEBUFFER,
+                    GL_FRAMEBUFFER_COMPLETE, GL_RENDERBUFFER,
+                },
             },
+            RenderError,
         },
-        RenderError,
     },
     std::rc::Rc,
 };
 
 pub struct GlRenderBuffer {
-    pub img: Rc<EglImage>,
+    pub _img: Option<Rc<EglImage>>,
     pub ctx: Rc<EglContext>,
+    pub width: i32,
+    pub height: i32,
+    pub format: &'static Format,
     rbo: GLuint,
 }
 
 impl GlRenderBuffer {
+    pub(in crate::gfx_apis::gl) unsafe fn new(
+        ctx: &Rc<EglContext>,
+        width: i32,
+        height: i32,
+        format: &'static Format,
+    ) -> Result<Rc<GlRenderBuffer>, RenderError> {
+        let gles = &ctx.dpy.gles;
+        let mut rbo = 0;
+        (gles.glGenRenderbuffers)(1, &mut rbo);
+        (gles.glBindRenderbuffer)(GL_RENDERBUFFER, rbo);
+        (gles.glRenderbufferStorage)(GL_RENDERBUFFER, format.gl_internal_format, width, height);
+        (gles.glBindRenderbuffer)(GL_RENDERBUFFER, 0);
+        Ok(Rc::new(GlRenderBuffer {
+            _img: None,
+            ctx: ctx.clone(),
+            width,
+            height,
+            format,
+            rbo,
+        }))
+    }
+
     pub(in crate::gfx_apis::gl) unsafe fn from_image(
         img: &Rc<EglImage>,
         ctx: &Rc<EglContext>,
@@ -36,8 +64,11 @@ impl GlRenderBuffer {
             .glEGLImageTargetRenderbufferStorageOES(GL_RENDERBUFFER, GLeglImageOES(img.img.0));
         (gles.glBindRenderbuffer)(GL_RENDERBUFFER, 0);
         Ok(Rc::new(GlRenderBuffer {
-            img: img.clone(),
+            _img: Some(img.clone()),
             ctx: ctx.clone(),
+            width: img.dmabuf.width,
+            height: img.dmabuf.height,
+            format: img.dmabuf.format,
             rbo,
         }))
     }
@@ -62,8 +93,8 @@ impl GlRenderBuffer {
             _tex: None,
             ctx: self.ctx.clone(),
             fbo,
-            width: self.img.dmabuf.width,
-            height: self.img.dmabuf.height,
+            width: self.width,
+            height: self.height,
         };
         if status != GL_FRAMEBUFFER_COMPLETE {
             return Err(RenderError::CreateFramebuffer);

src/gfx_apis/gl/gl/sys.rs

@@ -14,6 +14,7 @@ pub type GLuint = c::c_uint;
 egl_transparent!(GLeglImageOES);
 
 pub const GL_RGBA: GLint = 0x1908;
+pub const GL_RGBA8: GLenum = 0x8058;
 pub const GL_BGRA_EXT: GLint = 0x80E1;
 pub const GL_CLAMP_TO_EDGE: GLint = 0x812F;
 pub const GL_COLOR_ATTACHMENT0: GLenum = 0x8CE0;
@@ -49,6 +50,7 @@ dynload! {
     GLESV2: GlesV2 from "libGLESv2.so" {
         glGetString: unsafe fn(name: GLenum) -> *const u8,
         glGenRenderbuffers: unsafe fn(n: GLsizei, renderbuffers: *mut GLuint),
+        glRenderbufferStorage: unsafe fn(target: GLenum, format: GLenum, width: GLsizei, height: GLsizei),
         glDeleteRenderbuffers: unsafe fn(n: GLsizei, renderbuffers: *const GLuint),
         glBindRenderbuffer: unsafe fn(target: GLenum, renderbuffer: GLuint),
         glGenFramebuffers: unsafe fn(n: GLsizei, framebuffers: *mut GLuint),

src/gfx_apis/gl/renderer/context.rs

@@ -255,4 +255,17 @@ impl GfxContext for GlRenderContext {
     fn gfx_api(&self) -> GfxApi {
         GfxApi::OpenGl
     }
+
+    fn create_fb(
+        self: Rc<Self>,
+        width: i32,
+        height: i32,
+        _stride: i32,
+        format: &'static Format,
+    ) -> Result<Rc<dyn GfxFramebuffer>, GfxError> {
+        let fb = self.ctx.with_current(|| unsafe {
+            GlRenderBuffer::new(&self.ctx, width, height, format)?.create_framebuffer()
+        })?;
+        Ok(Rc::new(Framebuffer { ctx: self, gl: fb }))
+    }
 }

src/gfx_apis/gl/renderer/framebuffer.rs

@@ -120,6 +120,6 @@ impl GfxFramebuffer for Framebuffer {
     }
 
     fn format(&self) -> &'static Format {
-        self.gl.rb.img.dmabuf.format
+        self.gl.rb.format
     }
 }