Auto merge of #648 - glennw:zb, r=kvark

bors-servo · web-flow · commit 56131c91c5eb · 2016-12-22T18:06:06.000-08:00
Use z-buffer for rejecting opaque fragments.  This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/webrender/648)
diff --git a/replay/src/main.rs b/replay/src/main.rs
@@ -119,7 +119,6 @@ fn main() {
         debug: false,
         enable_subpixel_aa: false,
         clear_framebuffer: true,
-        clear_empty_tiles: false,
         clear_color: ColorF::new(1.0, 1.0, 1.0, 1.0),
     };
 
diff --git a/sample/src/main.rs b/sample/src/main.rs
@@ -85,7 +85,6 @@ fn main() {
         renderer_kind: RendererKind::Native,
         enable_subpixel_aa: false,
         clear_framebuffer: true,
-        clear_empty_tiles: false,
         clear_color: ColorF::new(1.0, 1.0, 1.0, 1.0),
     };
 
diff --git a/webrender/res/prim_shared.glsl b/webrender/res/prim_shared.glsl
@@ -61,6 +61,7 @@ in int aClipTaskIndex;
 in int aLayerIndex;
 in int aElementIndex;
 in ivec2 aUserData;
+in int aZIndex;
 
 // get_fetch_uv is a macro to work around a macOS Intel driver parsing bug.
 // TODO: convert back to a function once the driver issues are resolved, if ever.
@@ -250,6 +251,7 @@ struct PrimitiveInstance {
     int clip_task_index;
     int layer_index;
     int sub_index;
+    int z;
     ivec2 user_data;
 };
 
@@ -263,6 +265,7 @@ PrimitiveInstance fetch_prim_instance() {
     pi.layer_index = aLayerIndex;
     pi.sub_index = aElementIndex;
     pi.user_data = aUserData;
+    pi.z = aZIndex;
 
     return pi;
 }
@@ -300,6 +303,7 @@ struct Primitive {
     // this index allows the vertex shader to recognize the difference
     int sub_index;
     ivec2 user_data;
+    float z;
 };
 
 Primitive load_primitive_custom(PrimitiveInstance pi) {
@@ -316,6 +320,7 @@ Primitive load_primitive_custom(PrimitiveInstance pi) {
     prim.prim_index = pi.specific_prim_index;
     prim.sub_index = pi.sub_index;
     prim.user_data = pi.user_data;
+    prim.z = float(pi.z);
 
     return prim;
 }
@@ -388,6 +393,7 @@ struct VertexInfo {
 
 VertexInfo write_vertex(vec4 instance_rect,
                         vec4 local_clip_rect,
+                        float z,
                         Layer layer,
                         Tile tile) {
     vec2 p0 = floor(0.5 + instance_rect.xy * uDevicePixelRatio) / uDevicePixelRatio;
@@ -415,7 +421,7 @@ VertexInfo write_vertex(vec4 instance_rect,
 
     vec2 final_pos = clamped_pos + tile.screen_origin_task_origin.zw - tile.screen_origin_task_origin.xy;
 
-    gl_Position = uTransform * vec4(final_pos, 0, 1);
+    gl_Position = uTransform * vec4(final_pos, z, 1.0);
 
     VertexInfo vi = VertexInfo(Rect(p0, p1), local_clamped_pos.xy, clamped_pos.xy);
     return vi;
@@ -431,6 +437,7 @@ struct TransformVertexInfo {
 
 TransformVertexInfo write_transform_vertex(vec4 instance_rect,
                                            vec4 local_clip_rect,
+                                           float z,
                                            Layer layer,
                                            Tile tile) {
     vec2 lp0_base = instance_rect.xy;
@@ -482,7 +489,7 @@ TransformVertexInfo write_transform_vertex(vec4 instance_rect,
     // apply the task offset
     vec2 final_pos = clamped_pos + tile.screen_origin_task_origin.zw - tile.screen_origin_task_origin.xy;
 
-    gl_Position = uTransform * vec4(final_pos, 0.0, 1.0);
+    gl_Position = uTransform * vec4(final_pos, z, 1.0);
 
     return TransformVertexInfo(layer_pos.xyw, clamped_pos, clipped_local_rect);
 }
diff --git a/webrender/res/ps_angle_gradient.vs.glsl b/webrender/res/ps_angle_gradient.vs.glsl
@@ -9,6 +9,7 @@ void main(void) {
 
     VertexInfo vi = write_vertex(prim.local_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
 
diff --git a/webrender/res/ps_blend.vs.glsl b/webrender/res/ps_blend.vs.glsl
@@ -5,6 +5,7 @@
 
 struct Blend {
     ivec4 src_id_target_id_op_amount;
+    int z;
 };
 
 Blend fetch_blend() {
@@ -15,6 +16,7 @@ Blend fetch_blend() {
                                              pi.render_task_index,
                                              pi.sub_index,
                                              pi.user_data.y);
+    blend.z = pi.z;
 
     return blend;
 }
@@ -40,5 +42,5 @@ void main(void) {
     vOp = blend.src_id_target_id_op_amount.z;
     vAmount = blend.src_id_target_id_op_amount.w / 65535.0;
 
-    gl_Position = uTransform * vec4(local_pos, 0, 1);
+    gl_Position = uTransform * vec4(local_pos, blend.z, 1.0);
 }
diff --git a/webrender/res/ps_border.vs.glsl b/webrender/res/ps_border.vs.glsl
@@ -136,6 +136,7 @@ void main(void) {
 #ifdef WR_FEATURE_TRANSFORM
     TransformVertexInfo vi = write_transform_vertex(segment_rect,
                                                     prim.local_clip_rect,
+                                                    prim.z,
                                                     prim.layer,
                                                     prim.tile);
     vLocalPos = vi.local_pos;
@@ -145,6 +146,7 @@ void main(void) {
 #else
     VertexInfo vi = write_vertex(segment_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
     vLocalPos = vi.local_clamped_pos.xy;
diff --git a/webrender/res/ps_box_shadow.vs.glsl b/webrender/res/ps_box_shadow.vs.glsl
@@ -10,6 +10,7 @@ void main(void) {
 
     VertexInfo vi = write_vertex(segment_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
 
diff --git a/webrender/res/ps_cache_image.vs.glsl b/webrender/res/ps_cache_image.vs.glsl
@@ -11,6 +11,7 @@ void main(void) {
 
     VertexInfo vi = write_vertex(prim.local_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
 
diff --git a/webrender/res/ps_composite.vs.glsl b/webrender/res/ps_composite.vs.glsl
@@ -5,6 +5,7 @@
 
 struct Composite {
     ivec4 src0_src1_target_id_op;
+    int z;
 };
 
 Composite fetch_composite() {
@@ -14,6 +15,7 @@ Composite fetch_composite() {
     composite.src0_src1_target_id_op = ivec4(pi.user_data.xy,
                                              pi.render_task_index,
                                              pi.sub_index);
+    composite.z = pi.z;
 
     return composite;
 }
@@ -44,5 +46,5 @@ void main(void) {
 
     vOp = composite.src0_src1_target_id_op.w;
 
-    gl_Position = uTransform * vec4(local_pos, 0, 1);
+    gl_Position = uTransform * vec4(local_pos, composite.z, 1.0);
 }
diff --git a/webrender/res/ps_gradient.vs.glsl b/webrender/res/ps_gradient.vs.glsl
@@ -39,6 +39,7 @@ void main(void) {
 #ifdef WR_FEATURE_TRANSFORM
     TransformVertexInfo vi = write_transform_vertex(segment_rect,
                                                     prim.local_clip_rect,
+                                                    prim.z,
                                                     prim.layer,
                                                     prim.tile);
     vLocalRect = vi.clipped_local_rect;
@@ -47,6 +48,7 @@ void main(void) {
 #else
     VertexInfo vi = write_vertex(segment_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
 
diff --git a/webrender/res/ps_image.vs.glsl b/webrender/res/ps_image.vs.glsl
@@ -11,13 +11,15 @@ void main(void) {
 #ifdef WR_FEATURE_TRANSFORM
     TransformVertexInfo vi = write_transform_vertex(prim.local_rect,
                                                     prim.local_clip_rect,
+                                                    prim.z,
                                                     prim.layer,
                                                     prim.tile);
     vLocalRect = vi.clipped_local_rect;
     vLocalPos = vi.local_pos;
 #else
     VertexInfo vi = write_vertex(prim.local_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
     vLocalPos = vi.local_clamped_pos - vi.local_rect.p0;
diff --git a/webrender/res/ps_rectangle.vs.glsl b/webrender/res/ps_rectangle.vs.glsl
@@ -10,13 +10,15 @@ void main(void) {
 #ifdef WR_FEATURE_TRANSFORM
     TransformVertexInfo vi = write_transform_vertex(prim.local_rect,
                                                     prim.local_clip_rect,
+                                                    prim.z,
                                                     prim.layer,
                                                     prim.tile);
     vLocalRect = vi.clipped_local_rect;
     vLocalPos = vi.local_pos;
 #else
     VertexInfo vi = write_vertex(prim.local_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
 #endif
diff --git a/webrender/res/ps_text_run.vs.glsl b/webrender/res/ps_text_run.vs.glsl
@@ -14,6 +14,7 @@ void main(void) {
 #ifdef WR_FEATURE_TRANSFORM
     TransformVertexInfo vi = write_transform_vertex(local_rect,
                                                     prim.local_clip_rect,
+                                                    prim.z,
                                                     prim.layer,
                                                     prim.tile);
     vLocalRect = vi.clipped_local_rect;
@@ -22,6 +23,7 @@ void main(void) {
 #else
     VertexInfo vi = write_vertex(local_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
     vec2 f = (vi.local_clamped_pos - vi.local_rect.p0) / (vi.local_rect.p1 - vi.local_rect.p0);
diff --git a/webrender/res/ps_yuv_image.vs.glsl b/webrender/res/ps_yuv_image.vs.glsl
@@ -8,13 +8,15 @@ void main(void) {
 #ifdef WR_FEATURE_TRANSFORM
     TransformVertexInfo vi = write_transform_vertex(prim.local_rect,
                                                     prim.local_clip_rect,
+                                                    prim.z,
                                                     prim.layer,
                                                     prim.tile);
     vLocalRect = vi.clipped_local_rect;
     vLocalPos = vi.local_pos;
 #else
     VertexInfo vi = write_vertex(prim.local_rect,
                                  prim.local_clip_rect,
+                                 prim.z,
                                  prim.layer,
                                  prim.tile);
     vLocalPos = vi.local_clamped_pos - vi.local_rect.p0;
diff --git a/webrender/src/device.rs b/webrender/src/device.rs
@@ -48,6 +48,11 @@ lazy_static! {
     };
 }
 
+#[repr(u32)]
+pub enum DepthFunction {
+    Less = gl::LESS,
+}
+
 #[derive(Copy, Clone, Debug, PartialEq)]
 pub enum TextureTarget {
     Default,
@@ -172,6 +177,7 @@ impl VertexFormat {
                                 VertexAttribute::ClipTaskIndex,
                                 VertexAttribute::LayerIndex,
                                 VertexAttribute::ElementIndex,
+                                VertexAttribute::ZIndex,
                                ].into_iter() {
                     gl::enable_vertex_attrib_array(attrib as gl::GLuint);
                     gl::vertex_attrib_divisor(attrib as gl::GLuint, 1);
@@ -375,6 +381,7 @@ impl Program {
         gl::bind_attrib_location(self.id, VertexAttribute::LayerIndex as gl::GLuint, "aLayerIndex");
         gl::bind_attrib_location(self.id, VertexAttribute::ElementIndex as gl::GLuint, "aElementIndex");
         gl::bind_attrib_location(self.id, VertexAttribute::UserData as gl::GLuint, "aUserData");
+        gl::bind_attrib_location(self.id, VertexAttribute::ZIndex as gl::GLuint, "aZIndex");
 
         gl::bind_attrib_location(self.id, ClearAttribute::Rectangle as gl::GLuint, "aClearRectangle");
 
@@ -1127,6 +1134,21 @@ impl Device {
                                                   texture_id.name,
                                                   0,
                                                   fbo_index as gl::GLint);
+
+                    // TODO(gw): Share depth render buffer between FBOs to
+                    //           save memory!
+                    // TODO(gw): Free these renderbuffers on exit!
+                    let renderbuffer_ids = gl::gen_renderbuffers(1);
+                    let depth_rb = renderbuffer_ids[0];
+                    gl::bind_renderbuffer(gl::RENDERBUFFER, depth_rb);
+                    gl::renderbuffer_storage(gl::RENDERBUFFER,
+                                             gl::DEPTH_COMPONENT24,
+                                             texture.width as gl::GLsizei,
+                                             texture.height as gl::GLsizei);
+                    gl::framebuffer_renderbuffer(gl::FRAMEBUFFER,
+                                                 gl::DEPTH_ATTACHMENT,
+                                                 gl::RENDERBUFFER,
+                                                 depth_rb);
                 }
             }
             None => {
@@ -1762,15 +1784,42 @@ impl Device {
         }
     }
 
-    pub fn clear_color(&self, c: [f32; 4]) {
-        gl::clear_color(c[0], c[1], c[2], c[3]);
-        gl::clear(gl::COLOR_BUFFER_BIT);
+    pub fn clear_target(&self,
+                        color: Option<[f32; 4]>,
+                        depth: Option<f32>) {
+        let mut clear_bits = 0;
+
+        if let Some(color) = color {
+            gl::clear_color(color[0], color[1], color[2], color[3]);
+            clear_bits |= gl::COLOR_BUFFER_BIT;
+        }
+
+        if let Some(depth) = depth {
+            gl::clear_depth(depth as f64);
+            clear_bits |= gl::DEPTH_BUFFER_BIT;
+        }
+
+        if clear_bits != 0 {
+            gl::clear(clear_bits);
+        }
+    }
+
+    pub fn enable_depth(&self) {
+        gl::enable(gl::DEPTH_TEST);
     }
 
     pub fn disable_depth(&self) {
         gl::disable(gl::DEPTH_TEST);
     }
 
+    pub fn set_depth_func(&self, depth_func: DepthFunction) {
+        gl::depth_func(depth_func as gl::GLuint);
+    }
+
+    pub fn enable_depth_write(&self) {
+        gl::depth_mask(true);
+    }
+
     pub fn disable_depth_write(&self) {
         gl::depth_mask(false);
     }
diff --git a/webrender/src/frame.rs b/webrender/src/frame.rs
@@ -513,7 +513,16 @@ impl Frame {
         self.layers.insert(root_fixed_layer_id, layer.clone());
         self.layers.insert(root_scroll_layer_id, layer);
 
+        let background_color = root_pipeline.background_color.and_then(|color| {
+            if color.a > 0.0 {
+                Some(color)
+            } else {
+                None
+            }
+        });
+
         let mut frame_builder = FrameBuilder::new(root_pipeline.viewport_size,
+                                                  background_color,
                                                   self.debug,
                                                   self.frame_builder_config);
 
diff --git a/webrender/src/internal_types.rs b/webrender/src/internal_types.rs
@@ -237,6 +237,7 @@ pub enum VertexAttribute {
     LayerIndex,
     ElementIndex,
     UserData,
+    ZIndex,
 }
 
 #[derive(Clone, Copy, Debug)]
diff --git a/webrender/src/renderer.rs b/webrender/src/renderer.rs
diff --git a/webrender/src/tiling.rs b/webrender/src/tiling.rs
diff --git a/wrench/src/wrench.rs b/wrench/src/wrench.rs
