From dab1dda90344169e61672433c9d3218c87b491b3 Mon Sep 17 00:00:00 2001
From: kd-11 <karokidii@gmail.com>
Date: Wed, 6 Apr 2016 00:43:32 +0300
Subject: [PATCH] Specify buffers to read when blitting output to backbuffer

---
 rpcs3/Emu/RSX/GL/gl_helpers.cpp        | 8 ++++++++
 rpcs3/Emu/RSX/GL/gl_helpers.h          | 2 ++
 rpcs3/Emu/RSX/GL/gl_render_targets.cpp | 7 +++++++
 3 files changed, 17 insertions(+)

diff --git a/rpcs3/Emu/RSX/GL/gl_helpers.cpp b/rpcs3/Emu/RSX/GL/gl_helpers.cpp
index 6274d3b0d3..862773713e 100644
--- a/rpcs3/Emu/RSX/GL/gl_helpers.cpp
+++ b/rpcs3/Emu/RSX/GL/gl_helpers.cpp
@@ -122,6 +122,14 @@ namespace gl
 		__glcheck glDrawBuffers((GLsizei)ids.size(), ids.data());
 	}
 
+	void fbo::read_buffer(const attachment& buffer) const
+	{
+		save_binding_state save(*this);
+		GLenum buf = buffer.id();
+
+		__glcheck glReadBuffer(buf);
+	}
+
 	void fbo::draw_arrays(rsx::primitive_type mode, GLsizei count, GLint first) const
 	{
 		save_binding_state save(*this);
diff --git a/rpcs3/Emu/RSX/GL/gl_helpers.h b/rpcs3/Emu/RSX/GL/gl_helpers.h
index 0dbb35dad2..d4ef6f883c 100644
--- a/rpcs3/Emu/RSX/GL/gl_helpers.h
+++ b/rpcs3/Emu/RSX/GL/gl_helpers.h
@@ -1550,6 +1550,8 @@ namespace gl
 		void recreate();
 		void draw_buffer(const attachment& buffer) const;
 		void draw_buffers(const std::initializer_list<attachment>& indexes) const;
+		
+		void read_buffer(const attachment& buffer) const;
 
 		void draw_arrays(rsx::primitive_type mode, GLsizei count, GLint first = 0) const;
 		void draw_arrays(const buffer& buffer, rsx::primitive_type mode, GLsizei count, GLint first = 0) const;
diff --git a/rpcs3/Emu/RSX/GL/gl_render_targets.cpp b/rpcs3/Emu/RSX/GL/gl_render_targets.cpp
index 453078841c..0aef73fc28 100644
--- a/rpcs3/Emu/RSX/GL/gl_render_targets.cpp
+++ b/rpcs3/Emu/RSX/GL/gl_render_targets.cpp
@@ -76,6 +76,7 @@ void GLGSRender::init_buffers(bool skip_reading)
 
 	if (draw_fbo && !m_rtts_dirty)
 		return;
+
 	m_rtts_dirty = false;
 
 	m_rtts.prepare_render_target(nullptr, surface_format, clip_horizontal, clip_vertical, rsx::to_surface_target(rsx::method_registers[NV4097_SET_SURFACE_COLOR_TARGET]),
@@ -88,9 +89,12 @@ void GLGSRender::init_buffers(bool skip_reading)
 		if (std::get<0>(m_rtts.m_bound_render_targets[i]) != 0)
 			__glcheck draw_fbo.color[i] = *std::get<1>(m_rtts.m_bound_render_targets[i]);
 	}
+
 	if (std::get<0>(m_rtts.m_bound_depth_stencil) != 0)
 		__glcheck draw_fbo.depth = *std::get<1>(m_rtts.m_bound_depth_stencil);
+
 	__glcheck draw_fbo.check();
+	__glcheck draw_fbo.read_buffer(draw_fbo.color[0]);
 
 
 	switch (rsx::to_surface_target(rsx::method_registers[NV4097_SET_SURFACE_COLOR_TARGET]))
@@ -102,8 +106,11 @@ void GLGSRender::init_buffers(bool skip_reading)
 		break;
 
 	case rsx::surface_target::surface_b:
+	{
 		__glcheck draw_fbo.draw_buffer(draw_fbo.color[1]);
+		__glcheck draw_fbo.read_buffer(draw_fbo.color[1]);
 		break;
+	}
 
 	case rsx::surface_target::surfaces_a_b:
 		__glcheck draw_fbo.draw_buffers({ draw_fbo.color[0], draw_fbo.color[1] });