LibAccelGfx+WebContent: Use the same Painter across page repaints

In the upcoming changes, Painter will be used to store the state of
OpenGL context. For example, if Painter is aware of the shader that
have already been loaded, it will be possible to reuse them across
repaints. Also, it would be possible to manage state of loaded textures
and add/remove them depending on which ones are present in the next
sequence of painting commands.

Userland/Libraries/LibAccelGfx/Context.cpp

@@ -69,6 +69,12 @@ OwnPtr<Context> Context::create()
     };
     EGLContext egl_context = eglCreateContext(egl_display, egl_config, EGL_NO_CONTEXT, context_attributes);
 
+    EGLBoolean result = eglMakeCurrent(egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE, egl_context);
+    if (result == EGL_FALSE) {
+        dbgln("eglMakeCurrent failed");
+        VERIFY_NOT_REACHED();
+    }
+
     return make<Context>(egl_display, egl_context, egl_config);
 }
 

Userland/Libraries/LibAccelGfx/Painter.cpp

@@ -33,17 +33,23 @@ static ColorComponents gfx_color_to_opengl_color(Gfx::Color color)
 
 Gfx::FloatRect Painter::to_clip_space(Gfx::FloatRect const& screen_rect) const
 {
-    float x = 2.0f * screen_rect.x() / m_canvas.width() - 1.0f;
-    float y = -1.0f + 2.0f * screen_rect.y() / m_canvas.height();
+    float x = 2.0f * screen_rect.x() / m_canvas->width() - 1.0f;
+    float y = -1.0f + 2.0f * screen_rect.y() / m_canvas->height();
 
-    float width = 2.0f * screen_rect.width() / m_canvas.width();
-    float height = 2.0f * screen_rect.height() / m_canvas.height();
+    float width = 2.0f * screen_rect.width() / m_canvas->width();
+    float height = 2.0f * screen_rect.height() / m_canvas->height();
 
     return { x, y, width, height };
 }
 
-Painter::Painter(Canvas& canvas)
-    : m_canvas(canvas)
+OwnPtr<Painter> Painter::create()
+{
+    auto& context = Context::the();
+    return make<Painter>(context);
+}
+
+Painter::Painter(Context& context)
+    : m_context(context)
 {
     m_state_stack.empend(State());
 }
@@ -171,7 +177,7 @@ void Painter::restore()
 
 void Painter::flush()
 {
-    m_canvas.flush();
+    m_canvas->flush();
 }
 
 }

Userland/Libraries/LibAccelGfx/Painter.h

@@ -8,6 +8,7 @@
 
 #include <AK/Noncopyable.h>
 #include <AK/Vector.h>
+#include <LibAccelGfx/Canvas.h>
 #include <LibAccelGfx/Forward.h>
 #include <LibGfx/AffineTransform.h>
 #include <LibGfx/Forward.h>
@@ -19,7 +20,9 @@ class Painter {
     AK_MAKE_NONMOVABLE(Painter);
 
 public:
-    Painter(Canvas&);
+    static OwnPtr<Painter> create();
+
+    Painter(Context&);
     ~Painter();
 
     void clear(Gfx::Color);
@@ -33,10 +36,12 @@ public:
     void fill_rect(Gfx::FloatRect, Gfx::Color);
     void fill_rect(Gfx::IntRect, Gfx::Color);
 
-private:
+    void set_canvas(Canvas& canvas) { m_canvas = canvas; }
     void flush();
 
-    Canvas& m_canvas;
+private:
+    Context& m_context;
+    Optional<Canvas> m_canvas;
 
     struct State {
         Gfx::AffineTransform transform;

Userland/Libraries/LibWeb/Painting/PaintingCommandExecutorGPU.cpp

@@ -8,16 +8,14 @@
 
 namespace Web::Painting {
 
-PaintingCommandExecutorGPU::PaintingCommandExecutorGPU(Gfx::Bitmap& bitmap)
-    : m_target_bitmap(bitmap)
-    , m_canvas(AccelGfx::Canvas::create(AccelGfx::Context::the(), bitmap))
-    , m_painter(m_canvas)
+PaintingCommandExecutorGPU::PaintingCommandExecutorGPU(AccelGfx::Painter& painter)
+    : m_painter(painter)
 {
 }
 
 PaintingCommandExecutorGPU::~PaintingCommandExecutorGPU()
 {
-    m_canvas.flush();
+    m_painter.flush();
 }
 
 CommandResult PaintingCommandExecutorGPU::draw_text_run(Color const&, Gfx::IntPoint const&, String const&, Gfx::Font const&)

Userland/Libraries/LibWeb/Painting/PaintingCommandExecutorGPU.h

@@ -50,15 +50,13 @@ public:
 
     bool would_be_fully_clipped_by_painter(Gfx::IntRect) const override;
 
-    PaintingCommandExecutorGPU(Gfx::Bitmap& bitmap);
+    PaintingCommandExecutorGPU(AccelGfx::Painter& painter);
     ~PaintingCommandExecutorGPU() override;
 
 private:
     AccelGfx::Painter& painter() { return m_painter; }
 
-    Gfx::Bitmap& m_target_bitmap;
-    AccelGfx::Canvas m_canvas;
-    AccelGfx::Painter m_painter;
+    AccelGfx::Painter& m_painter;
 };
 
 }

Userland/Services/WebContent/PageHost.cpp

@@ -27,6 +27,13 @@
 
 namespace WebContent {
 
+static bool s_use_gpu_painter = false;
+
+void PageHost::set_use_gpu_painter()
+{
+    s_use_gpu_painter = true;
+}
+
 PageHost::PageHost(ConnectionFromClient& client)
     : m_client(client)
     , m_page(make<Web::Page>(*this))
@@ -36,17 +43,16 @@ PageHost::PageHost(ConnectionFromClient& client)
         m_client.async_did_invalidate_content_rect({ m_invalidation_rect.x().value(), m_invalidation_rect.y().value(), m_invalidation_rect.width().value(), m_invalidation_rect.height().value() });
         m_invalidation_rect = {};
     });
+
+    if (s_use_gpu_painter) {
+#ifdef HAS_ACCELERATED_GRAPHICS
+        m_accelerated_painter = AccelGfx::Painter::create();
+#endif
+    }
 }
 
 PageHost::~PageHost() = default;
 
-static bool s_use_gpu_painter = false;
-
-void PageHost::set_use_gpu_painter()
-{
-    s_use_gpu_painter = true;
-}
-
 void PageHost::set_has_focus(bool has_focus)
 {
     m_has_focus = has_focus;
@@ -158,8 +164,11 @@ void PageHost::paint(Web::DevicePixelRect const& content_rect, Gfx::Bitmap& targ
 
     if (s_use_gpu_painter) {
 #ifdef HAS_ACCELERATED_GRAPHICS
-        Web::Painting::PaintingCommandExecutorGPU painting_command_executor(target);
+        auto canvas = AccelGfx::Canvas::create(AccelGfx::Context::the(), target);
+        m_accelerated_painter->set_canvas(canvas);
+        Web::Painting::PaintingCommandExecutorGPU painting_command_executor(*m_accelerated_painter);
         recording_painter.execute(painting_command_executor);
+        m_accelerated_painter->flush();
 #endif
     } else {
         Web::Painting::PaintingCommandExecutorCPU painting_command_executor(target);

Userland/Services/WebContent/PageHost.h

@@ -7,6 +7,7 @@
 
 #pragma once
 
+#include <LibAccelGfx/Forward.h>
 #include <LibGfx/Rect.h>
 #include <LibWeb/Page/Page.h>
 #include <LibWeb/PixelUnits.h>
@@ -139,6 +140,10 @@ private:
     Web::CSS::PreferredColorScheme m_preferred_color_scheme { Web::CSS::PreferredColorScheme::Auto };
 
     RefPtr<WebDriverConnection> m_webdriver;
+
+#ifdef HAS_ACCELERATED_GRAPHICS
+    OwnPtr<AccelGfx::Painter> m_accelerated_painter;
+#endif
 };
 
 }