VideoCommon: Add support for Abstract Framebuffers

Source/Core/VideoCommon/AbstractFramebuffer.cpp

@@ -0,0 +1,55 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "VideoCommon/AbstractFramebuffer.h"
+#include "VideoCommon/AbstractTexture.h"
+
+AbstractFramebuffer::AbstractFramebuffer(AbstractTextureFormat color_format,
+                                         AbstractTextureFormat depth_format, u32 width, u32 height,
+                                         u32 layers, u32 samples)
+    : m_color_format(color_format), m_depth_format(depth_format), m_width(width), m_height(height),
+      m_layers(layers), m_samples(samples)
+{
+}
+
+AbstractFramebuffer::~AbstractFramebuffer() = default;
+
+bool AbstractFramebuffer::ValidateConfig(const AbstractTexture* color_attachment,
+                                         const AbstractTexture* depth_attachment)
+{
+  // Must have at least a color or depth attachment.
+  if (!color_attachment && !depth_attachment)
+    return false;
+
+  // Currently we only expose a single mip level for render target textures.
+  // MSAA textures are not supported with mip levels on most backends, and it simplifies our
+  // handling of framebuffers.
+  auto CheckAttachment = [](const AbstractTexture* tex) {
+    return tex->GetConfig().rendertarget && tex->GetConfig().levels == 1;
+  };
+  if ((color_attachment && !CheckAttachment(color_attachment)) ||
+      depth_attachment && !CheckAttachment(depth_attachment))
+  {
+    return false;
+  }
+
+  // If both color and depth are present, their attributes must match.
+  if (color_attachment && depth_attachment)
+  {
+    if (color_attachment->GetConfig().width != depth_attachment->GetConfig().width ||
+        color_attachment->GetConfig().height != depth_attachment->GetConfig().height ||
+        color_attachment->GetConfig().layers != depth_attachment->GetConfig().layers ||
+        color_attachment->GetConfig().samples != depth_attachment->GetConfig().samples)
+    {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+MathUtil::Rectangle<int> AbstractFramebuffer::GetRect() const
+{
+  return MathUtil::Rectangle<int>(0, 0, static_cast<int>(m_width), static_cast<int>(m_height));
+}