From 1204f35f1e85607f4d6d44864de1419b27b9e9e4 Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Mon, 16 Feb 2015 21:58:24 -0800
Subject: [PATCH] --disable_framebuffer_readback

---
 src/xenia/gpu/gl4/command_processor.cc | 46 ++++++++++++++------------
 src/xenia/gpu/gl4/gl4_gpu-private.h    |  1 +
 src/xenia/gpu/gl4/gl4_gpu.cc           |  2 ++
 3 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/src/xenia/gpu/gl4/command_processor.cc b/src/xenia/gpu/gl4/command_processor.cc
index 7a9540116..4eebfc138 100644
--- a/src/xenia/gpu/gl4/command_processor.cc
+++ b/src/xenia/gpu/gl4/command_processor.cc
@@ -2396,29 +2396,31 @@ bool CommandProcessor::IssueCopy() {
   uint32_t w = copy_dest_pitch;
   uint32_t h = copy_dest_height;
 
-  // Make active so glReadPixels reads from us.
-  glBindFramebuffer(GL_READ_FRAMEBUFFER, source_framebuffer->framebuffer);
-  switch (copy_command) {
-    case CopyCommand::kConvert:
-      if (copy_src_select <= 3) {
-        // Source from a bound render target.
-        // glBindBuffer(GL_READ_FRAMEBUFFER, framebuffer)
-        glNamedFramebufferReadBuffer(source_framebuffer->framebuffer,
-                                     GL_COLOR_ATTACHMENT0 + copy_src_select);
-        glReadPixels(x, y, w, h, read_format, read_type, ptr);
-      } else {
-        // Source from the bound depth/stencil target.
-        glReadPixels(x, y, w, h, GL_DEPTH_STENCIL, read_type, ptr);
-      }
-      break;
-    case CopyCommand::kRaw:
-    case CopyCommand::kConstantOne:
-    case CopyCommand::kNull:
-    default:
-      // assert_unhandled_case(copy_command);
-      return false;
+  if (!FLAGS_disable_framebuffer_readback) {
+    // Make active so glReadPixels reads from us.
+    glBindFramebuffer(GL_READ_FRAMEBUFFER, source_framebuffer->framebuffer);
+    switch (copy_command) {
+      case CopyCommand::kConvert:
+        if (copy_src_select <= 3) {
+          // Source from a bound render target.
+          // glBindBuffer(GL_READ_FRAMEBUFFER, framebuffer)
+          glNamedFramebufferReadBuffer(source_framebuffer->framebuffer,
+                                       GL_COLOR_ATTACHMENT0 + copy_src_select);
+          glReadPixels(x, y, w, h, read_format, read_type, ptr);
+        } else {
+          // Source from the bound depth/stencil target.
+          glReadPixels(x, y, w, h, GL_DEPTH_STENCIL, read_type, ptr);
+        }
+        break;
+      case CopyCommand::kRaw:
+      case CopyCommand::kConstantOne:
+      case CopyCommand::kNull:
+      default:
+        // assert_unhandled_case(copy_command);
+        return false;
+    }
+    glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
   }
-  glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
 
   // Perform any requested clears.
   uint32_t copy_depth_clear = regs[XE_GPU_REG_RB_DEPTH_CLEAR].u32;
diff --git a/src/xenia/gpu/gl4/gl4_gpu-private.h b/src/xenia/gpu/gl4/gl4_gpu-private.h
index 3d14b5823..a374227a2 100644
--- a/src/xenia/gpu/gl4/gl4_gpu-private.h
+++ b/src/xenia/gpu/gl4/gl4_gpu-private.h
@@ -22,6 +22,7 @@ DECLARE_bool(gl_debug_output_synchronous);
 
 DECLARE_bool(vendor_gl_extensions);
 
+DECLARE_bool(disable_framebuffer_readback);
 DECLARE_bool(disable_textures);
 
 namespace xe {
diff --git a/src/xenia/gpu/gl4/gl4_gpu.cc b/src/xenia/gpu/gl4/gl4_gpu.cc
index be29dc6a5..bcbba56ea 100644
--- a/src/xenia/gpu/gl4/gl4_gpu.cc
+++ b/src/xenia/gpu/gl4/gl4_gpu.cc
@@ -22,6 +22,8 @@ DEFINE_bool(gl_debug_output_synchronous, true,
 DEFINE_bool(vendor_gl_extensions, true,
             "Enable vendor-specific (NV, AMD, etc) GL extensions.");
 
+DEFINE_bool(disable_framebuffer_readback, false,
+            "Disable framebuffer readback.");
 DEFINE_bool(disable_textures, false, "Disable textures and use colors only.");
 
 namespace xe {