gsdx hw: add API to manage sparse texture allocation

DX/GL should implement "CommitPages" to really commit memory

Note: CommitPages should also update the m_committed_size member

plugins/GSdx/Renderers/Common/GSTexture.cpp

@@ -25,11 +25,66 @@
 GSTexture::GSTexture()
 	: m_scale(1, 1)
 	, m_size(0, 0)
+	, m_committed_size(0, 0)
+	, m_gpu_page_size(0, 0)
 	, m_type(0)
 	, m_format(0)
+	, m_sparse(false)
 	, last_frame_used(0)
 	, LikelyOffset(false)
 	, OffsetHack_modx(0.0f)
 	, OffsetHack_mody(0.0f)
 {
 }
+
+void GSTexture::CommitRegion(const GSVector2i& region)
+{
+	if (!m_sparse)
+		return;
+
+	GSVector2i aligned_region = RoundUpPage(region);
+	aligned_region.x = std::max(m_committed_size.x, aligned_region.x);
+	aligned_region.y = std::max(m_committed_size.y, aligned_region.y);
+	if (aligned_region != m_committed_size)
+		CommitPages(aligned_region, true);
+}
+
+void GSTexture::Commit()
+{
+	if (!m_sparse)
+		return;
+
+	if (m_committed_size != m_size)
+		CommitPages(m_size, true);
+}
+
+void GSTexture::Uncommit()
+{
+	if (!m_sparse)
+		return;
+
+	GSVector2i zero = GSVector2i(0, 0);
+
+	if (m_committed_size != zero)
+		CommitPages(m_committed_size, false);
+}
+
+void GSTexture::SetGpuPageSize(const GSVector2i& page_size)
+{
+	ASSERT(std::bitset<32>(page_size.x + 1).count() == 1);
+	ASSERT(std::bitset<32>(page_size.y + 1).count() == 1);
+
+	m_gpu_page_size = page_size;
+}
+
+GSVector2i GSTexture::RoundUpPage(GSVector2i v)
+{
+	v.x = std::min(m_size.x, v.x);
+	v.y = std::min(m_size.y, v.y);
+	v.x += m_gpu_page_size.x;
+	v.y += m_gpu_page_size.y;
+	v.x &= ~m_gpu_page_size.x;
+	v.y &= ~m_gpu_page_size.y;
+
+	return v;
+}

plugins/GSdx/Renderers/Common/GSTexture.h

@@ -28,8 +28,11 @@ class GSTexture
 protected:
 	GSVector2 m_scale;
 	GSVector2i m_size;
+	GSVector2i m_committed_size;
+	GSVector2i m_gpu_page_size;
 	int m_type;
 	int m_format;
+	bool m_sparse;
 
 public:
 	struct GSMap {uint8* bits; int pitch;};
@@ -59,6 +62,14 @@ class GSTexture
 	int GetType() const {return m_type;}
 	int GetFormat() const {return m_format;}
 
+	virtual void CommitPages(const GSVector2i& region, bool commit) {};
+	void CommitRegion(const GSVector2i& region);
+	void Commit();
+	void Uncommit();
+	GSVector2i GetCommittedSize() const { return m_committed_size; }
+	void SetGpuPageSize(const GSVector2i& page_size);
+	GSVector2i RoundUpPage(GSVector2i v);
+
 	// frame number (arbitrary base) the texture was recycled on
 	// different purpose than texture cache ages, do not attempt to merge
 	unsigned last_frame_used;

plugins/GSdx/stdafx.h

@@ -117,6 +117,7 @@ typedef int64 sint64;
 #include <condition_variable>
 #include <functional>
 #include <memory>
+#include <bitset>
 
 #include <zlib.h>