OpenGL: allow uploads of buffers to hardware ahead-of-time

irr/include/IVideoDriver.h

@@ -310,6 +310,18 @@ public:
 	0 or another texture first. */
 	virtual void removeAllTextures() = 0;
 
+	//! Eagerly upload buffer to hardware
+	/** This can be a good idea if you have a newly created or modified buffer,
+	which you know you will draw in the near future (e.g. end of same frame,
+	or next frame), because it gives the GPU driver to copy the contents. */
+	virtual void updateHardwareBuffer(const scene::IVertexBuffer *vb) = 0;
+
+	//! Eagerly upload buffer to hardware
+	/** This can be a good idea if you have a newly created or modified buffer,
+	which you know you will draw in the near future (e.g. end of same frame,
+	or next frame), because it gives the GPU driver to copy the contents. */
+	virtual void updateHardwareBuffer(const scene::IIndexBuffer *ib) = 0;
+
 	//! Remove hardware buffer
 	virtual void removeHardwareBuffer(const scene::IVertexBuffer *vb) = 0;
 

irr/src/CNullDriver.cpp

@@ -1167,6 +1167,24 @@ void CNullDriver::deleteHardwareBuffer(SHWBufferLink *HWBuffer)
 	delete HWBuffer;
 }
 
+void CNullDriver::updateHardwareBuffer(const scene::IVertexBuffer *vb)
+{
+	if (!vb)
+		return;
+	auto *link = getBufferLink(vb);
+	if (link)
+		updateHardwareBuffer(link);
+}
+
+void CNullDriver::updateHardwareBuffer(const scene::IIndexBuffer *ib)
+{
+	if (!ib)
+		return;
+	auto *link = getBufferLink(ib);
+	if (link)
+		updateHardwareBuffer(link);
+}
+
 void CNullDriver::removeHardwareBuffer(const scene::IVertexBuffer *vb)
 {
 	if (!vb)

irr/src/CNullDriver.h

@@ -348,6 +348,10 @@ protected:
 	virtual SHWBufferLink *createHardwareBuffer(const scene::IIndexBuffer *ib) { return 0; }
 
 public:
+	virtual void updateHardwareBuffer(const scene::IVertexBuffer *vb) override;
+
+	virtual void updateHardwareBuffer(const scene::IIndexBuffer *ib) override;
+
 	//! Remove hardware buffer
 	void removeHardwareBuffer(const scene::IVertexBuffer *vb) override;