From 79179c28ef7758099cfccf5acce33d3eae3ffe1c Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Fri, 2 Jan 2015 18:21:39 -0800
Subject: [PATCH] Experimenting with index ranges. Look unused by d3d :(

---
 src/xenia/gpu/gl4/command_processor.cc | 9 ++++++++-
 src/xenia/gpu/gl4/command_processor.h  | 2 ++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/xenia/gpu/gl4/command_processor.cc b/src/xenia/gpu/gl4/command_processor.cc
index 50b562051..d22c9527b 100644
--- a/src/xenia/gpu/gl4/command_processor.cc
+++ b/src/xenia/gpu/gl4/command_processor.cc
@@ -1311,8 +1311,15 @@ void CommandProcessor::PrepareDraw(DrawCommand* draw_command) {
   cmd.index_count = 0;
   cmd.index_buffer.address = nullptr;
 
-  // Generic stuff.
+  // Starting index when drawing indexed.
   cmd.start_index = regs[XE_GPU_REG_VGT_INDX_OFFSET].u32;
+
+  // Min/max index ranges. This is often [0,FFFF|FFFFFF], but if it's not we
+  // can use it to do a glDrawRangeElements.
+  cmd.min_index = regs[XE_GPU_REG_VGT_MIN_VTX_INDX].u32;
+  cmd.max_index = regs[XE_GPU_REG_VGT_MAX_VTX_INDX].u32;
+
+  // ?
   cmd.base_vertex = 0;
 
   cmd.state_data = nullptr;
diff --git a/src/xenia/gpu/gl4/command_processor.h b/src/xenia/gpu/gl4/command_processor.h
index 0d5a39c64..5a98fefaf 100644
--- a/src/xenia/gpu/gl4/command_processor.h
+++ b/src/xenia/gpu/gl4/command_processor.h
@@ -79,6 +79,8 @@ static_assert(sizeof(UniformDataBlock) <= 16 * 1024,
 struct DrawCommand {
   PrimitiveType prim_type;
   uint32_t start_index;
+  uint32_t min_index;
+  uint32_t max_index;
   uint32_t index_count;
   uint32_t base_vertex;