Implement WebGLContext resize

Author: MortimerGoro

webrender/src/device.rs

@@ -1042,6 +1042,10 @@ impl Device {
         self.raw_textures.insert(texture_id, (x0, y0, width, height));
     }
 
+    pub fn remove_raw_texture(&mut self, texture_id: TextureId) {
+        self.raw_textures.remove(&texture_id);
+    }
+
     fn set_texture_parameters(&mut self, target: gl::GLuint, filter: TextureFilter) {
         let filter = match filter {
             TextureFilter::Nearest => {

webrender/src/internal_types.rs

@@ -134,6 +134,17 @@ impl GLContextWrapper {
             }
         }
     }
+
+    pub fn resize(&mut self, size: &Size2D<i32>) -> Result<(), &'static str> {
+        match *self {
+            GLContextWrapper::Native(ref mut ctx) => {
+                ctx.resize(*size)
+            }
+            GLContextWrapper::OSMesa(ref mut ctx) => {
+                ctx.resize(*size)
+            }
+        }
+    }
 }
 
 pub type DeviceRect = TypedRect<i32, DevicePixel>;
@@ -338,6 +349,7 @@ pub enum TextureUpdateOp {
     Create(u32, u32, ImageFormat, TextureFilter, RenderTargetMode, Option<Vec<u8>>),
     Update(u32, u32, u32, u32, TextureUpdateDetails),
     Grow(u32, u32, ImageFormat, TextureFilter, RenderTargetMode),
+    Remove
 }
 
 pub struct TextureUpdate {

webrender/src/render_backend.rs

@@ -303,6 +303,21 @@ impl RenderBackend {
                                 tx.send(Err("Not implemented yet".to_owned())).unwrap();
                             }
                         }
+                        ApiMsg::ResizeWebGLContext(context_id, size) => {
+                            let ctx = self.webgl_contexts.get_mut(&context_id).unwrap();
+                            ctx.make_current();
+                            match ctx.resize(&size) {
+                                Ok(_) => {
+                                    // Update webgl texture size. Texture id may change too.
+                                    let (real_size, texture_id, _) = ctx.get_info();
+                                    self.resource_cache
+                                        .update_webgl_texture(context_id, TextureId::new(texture_id), real_size);
+                                },
+                                Err(msg) => {
+                                    error!("Error resizing WebGLContext: {}", msg);
+                                }
+                            }
+                        }
                         ApiMsg::WebGLCommand(context_id, command) => {
                             // TODO: Buffer the commands and only apply them here if they need to
                             // be synchronous.

webrender/src/renderer.rs

@@ -1033,6 +1033,9 @@ impl Renderer {
                             }
                         }
                     }
+                    TextureUpdateOp::Remove => {
+                        self.device.remove_raw_texture(update.id);
+                    }
                 }
             }
         }

webrender/src/resource_cache.rs

@@ -216,6 +216,18 @@ impl ResourceCache {
         self.texture_cache.add_raw_update(texture_id, size);
     }
 
+    pub fn update_webgl_texture(&mut self, id: WebGLContextId, texture_id: TextureId, size: Size2D<i32>) {
+        let prev_texture_id = *self.webgl_textures.get(&id).unwrap();
+
+        // Remove existing cache if texture id has changed
+        if prev_texture_id != texture_id {
+            self.texture_cache.add_raw_remove(prev_texture_id);
+        }
+        // Update new texture id and size
+        self.webgl_textures.insert(id, texture_id);
+        self.texture_cache.add_raw_update(texture_id, size);
+    }
+
     pub fn add_resource_list(&mut self, resource_list: &ResourceList, frame_id: FrameId) {
         // Update texture cache with any images that aren't yet uploaded to GPU.
         resource_list.for_each_image(|image_key, image_rendering| {

webrender/src/texture_cache.rs

@@ -779,6 +779,13 @@ impl TextureCache {
         })
     }
 
+    pub fn add_raw_remove(&mut self, id: TextureId) {
+        self.pending_updates.push(TextureUpdate {
+            id: id,
+            op: TextureUpdateOp::Remove
+        });
+    }
+
     pub fn update(&mut self,
                   image_id: TextureCacheItemId,
                   width: u32,

webrender_traits/src/api.rs

@@ -229,6 +229,11 @@ impl RenderApi {
         rx.recv().unwrap()
     }
 
+    pub fn resize_webgl_context(&self, context_id: WebGLContextId, size: &Size2D<i32>) {
+        let msg = ApiMsg::ResizeWebGLContext(context_id, *size);
+        self.api_sender.send(msg).unwrap();
+    }
+
     pub fn send_webgl_command(&self, context_id: WebGLContextId, command: WebGLCommand) {
         let msg = ApiMsg::WebGLCommand(context_id, command);
         self.api_sender.send(msg).unwrap();

webrender_traits/src/types.rs

@@ -55,6 +55,7 @@ pub enum ApiMsg {
     TranslatePointToLayerSpace(Point2D<f32>, IpcSender<(Point2D<f32>, PipelineId)>),
     GetScrollLayerState(IpcSender<Vec<ScrollLayerState>>),
     RequestWebGLContext(Size2D<i32>, GLContextAttributes, IpcSender<Result<(WebGLContextId, GLLimits), String>>),
+    ResizeWebGLContext(WebGLContextId, Size2D<i32>),
     WebGLCommand(WebGLContextId, WebGLCommand),
 }