render: don't require framebuffer to perform shm screencopies

src/gfx_apis/gl.rs

@@ -178,8 +178,8 @@ enum RenderError {
     ExternalUnsupported,
     #[error("OpenGL context does not support any formats")]
     NoSupportedFormats,
-    #[error("Unsupported operation")]
-    UnsupportedOperation,
+    #[error("Cannot convert a shm texture into a framebuffer")]
+    ShmTextureToFb,
 }
 
 #[derive(Default)]

src/gfx_apis/gl/renderer/context.rs

@@ -6,7 +6,7 @@ use {
             ResetStatus,
         },
         gfx_apis::gl::{
-            egl::{context::EglContext, display::EglDisplay},
+            egl::{context::EglContext, display::EglDisplay, image::EglImage},
             ext::GL_OES_EGL_IMAGE_EXTERNAL,
             gl::{
                 program::GlProgram, render_buffer::GlRenderBuffer, sys::GLint, texture::GlTexture,
@@ -190,6 +190,20 @@ impl GlRenderContext {
             format,
         }))
     }
+
+    pub fn image_to_fb(
+        self: &Rc<Self>,
+        img: &Rc<EglImage>,
+    ) -> Result<Rc<Framebuffer>, RenderError> {
+        self.ctx.with_current(|| unsafe {
+            let rb = GlRenderBuffer::from_image(img, &self.ctx)?;
+            let fb = rb.create_framebuffer()?;
+            Ok(Rc::new(Framebuffer {
+                ctx: self.clone(),
+                gl: fb,
+            }))
+        })
+    }
 }
 
 impl GfxContext for GlRenderContext {

src/gfx_apis/gl/renderer/framebuffer.rs

@@ -106,15 +106,16 @@ impl GfxFramebuffer for Framebuffer {
     }
 
     fn copy_to_shm(
-        &self,
+        self: Rc<Self>,
         x: i32,
         y: i32,
         width: i32,
         height: i32,
-        format: &Format,
+        _stride: i32,
+        format: &'static Format,
         shm: &[Cell<u8>],
     ) -> Result<(), GfxError> {
-        self.copy_to_shm(x, y, width, height, format, shm);
+        (*self).copy_to_shm(x, y, width, height, format, shm);
         Ok(())
     }
 

src/gfx_apis/gl/renderer/image.rs

@@ -2,9 +2,8 @@ use {
     crate::{
         gfx_api::{GfxError, GfxFramebuffer, GfxImage, GfxTexture},
         gfx_apis::gl::{
-            egl::image::EglImage,
-            gl::{render_buffer::GlRenderBuffer, texture::GlTexture},
-            Framebuffer, GlRenderContext, RenderError, Texture,
+            egl::image::EglImage, gl::texture::GlTexture, Framebuffer, GlRenderContext,
+            RenderError, Texture,
         },
     },
     std::rc::Rc,
@@ -34,14 +33,7 @@ impl Image {
     }
 
     fn to_framebuffer(&self) -> Result<Rc<Framebuffer>, RenderError> {
-        self.ctx.ctx.with_current(|| unsafe {
-            let rb = GlRenderBuffer::from_image(&self.gl, &self.ctx.ctx)?;
-            let fb = rb.create_framebuffer()?;
-            Ok(Rc::new(Framebuffer {
-                ctx: self.ctx.clone(),
-                gl: fb,
-            }))
-        })
+        self.ctx.image_to_fb(&self.gl)
     }
 }
 

src/gfx_apis/gl/renderer/texture.rs

@@ -2,7 +2,11 @@ use {
     crate::{
         format::Format,
         gfx_api::{GfxError, GfxTexture, TextureReservations},
-        gfx_apis::gl::{gl::texture::GlTexture, renderer::context::GlRenderContext, RenderError},
+        gfx_apis::gl::{
+            gl::texture::GlTexture,
+            renderer::{context::GlRenderContext, framebuffer::Framebuffer},
+            RenderError,
+        },
         video::dmabuf::DmaBuf,
     },
     std::{
@@ -34,6 +38,13 @@ impl Texture {
     pub fn height(&self) -> i32 {
         self.gl.height
     }
+
+    pub fn to_framebuffer(&self) -> Result<Rc<Framebuffer>, RenderError> {
+        match &self.gl.img {
+            Some(img) => self.ctx.image_to_fb(img),
+            _ => Err(RenderError::ShmTextureToFb),
+        }
+    }
 }
 
 impl GfxTexture for Texture {
@@ -51,15 +62,17 @@ impl GfxTexture for Texture {
 
     fn read_pixels(
         self: Rc<Self>,
-        _x: i32,
-        _y: i32,
-        _width: i32,
-        _height: i32,
+        x: i32,
+        y: i32,
+        width: i32,
+        height: i32,
         _stride: i32,
-        _format: &Format,
-        _shm: &[Cell<u8>],
+        format: &Format,
+        shm: &[Cell<u8>],
     ) -> Result<(), GfxError> {
-        Err(RenderError::UnsupportedOperation.into())
+        self.to_framebuffer()?
+            .copy_to_shm(x, y, width, height, format, shm);
+        Ok(())
     }
 
     fn dmabuf(&self) -> Option<&DmaBuf> {

src/gfx_apis/vulkan.rs

@@ -173,8 +173,6 @@ pub enum VulkanError {
         height: i32,
         stride: i32,
     },
-    #[error("Unsupported operation")]
-    UnsupportedOperation,
 }
 
 impl From<VulkanError> for GfxError {

src/gfx_apis/vulkan/image.rs

@@ -533,15 +533,18 @@ impl GfxFramebuffer for VulkanImage {
     }
 
     fn copy_to_shm(
-        &self,
-        _x: i32,
-        _y: i32,
-        _width: i32,
-        _height: i32,
-        _format: &Format,
-        _shm: &[Cell<u8>],
+        self: Rc<Self>,
+        x: i32,
+        y: i32,
+        width: i32,
+        height: i32,
+        stride: i32,
+        format: &'static Format,
+        shm: &[Cell<u8>],
     ) -> Result<(), GfxError> {
-        return Err(VulkanError::UnsupportedOperation.into());
+        self.renderer
+            .read_pixels(&self, x, y, width, height, stride, format, shm)
+            .map_err(|e| e.into())
     }
 
     fn format(&self) -> &'static Format {