[core] add generic base class for renderbuffers

2 files changed, 64 insertions, 0 deletions

diff --git a/src/mbgl/gfx/context.hpp b/src/mbgl/gfx/context.hpp
index e898006ff5..f9b7789696 100644
--- a/src/mbgl/gfx/context.hpp
+++ b/src/mbgl/gfx/context.hpp
@@ -5,6 +5,7 @@
 #include <mbgl/gfx/index_vector.hpp>
 #include <mbgl/gfx/index_buffer.hpp>
 #include <mbgl/gfx/texture.hpp>
+#include <mbgl/gfx/renderbuffer.hpp>
 #include <mbgl/gfx/draw_scope.hpp>
 #include <mbgl/gfx/program.hpp>
 #include <mbgl/gfx/types.hpp>
@@ -121,6 +122,17 @@ protected:
         TexturePixelType, TextureChannelDataType) = 0;
 
 public:
+    template <RenderbufferPixelType pixelType>
+    Renderbuffer<pixelType>
+    createRenderbuffer(const Size size) {
+        return { size, createRenderbufferResource(pixelType, size) };
+    }
+
+protected:
+    virtual std::unique_ptr<RenderbufferResource>
+    createRenderbufferResource(RenderbufferPixelType, Size) = 0;
+
+public:
     DrawScope createDrawScope() {
         return { createDrawScopeResource() };
     }
diff --git a/src/mbgl/gfx/renderbuffer.hpp b/src/mbgl/gfx/renderbuffer.hpp
new file mode 100644
index 0000000000..209b7ed3f9
--- /dev/null
+++ b/src/mbgl/gfx/renderbuffer.hpp
@@ -0,0 +1,52 @@
+#pragma once
+
+#include <mbgl/gfx/types.hpp>
+#include <mbgl/util/size.hpp>
+
+#include <memory>
+#include <cassert>
+
+namespace mbgl {
+namespace gfx {
+
+class RenderbufferResource {
+protected:
+    RenderbufferResource() = default;
+
+public:
+    virtual ~RenderbufferResource() = default;
+};
+
+template <RenderbufferPixelType renderbufferType>
+class Renderbuffer final {
+public:
+    Renderbuffer(const Size size_, std::unique_ptr<RenderbufferResource> resource_)
+        : size(size_), resource(std::move(resource_)) {
+    }
+
+    void setShouldClear(bool clear) {
+        dirty = clear;
+    }
+
+    bool needsClearing() const {
+        return dirty;
+    }
+
+    const Size& getSize() const {
+        return size;
+    }
+
+    template <typename T = RenderbufferResource>
+    T& getResource() const {
+        assert(resource);
+        return static_cast<T&>(*resource);
+    }
+
+protected:
+    Size size;
+    bool dirty = false;
+    std::unique_ptr<RenderbufferResource> resource;
+};
+
+} // namespace gfx
+} // namespace mbgl