From 99652c5eda7b0d89d547686484ccb9e2666154b1 Mon Sep 17 00:00:00 2001
From: Billy Laws <blaws05@gmail.com>
Date: Wed, 12 Jan 2022 22:59:00 +0000
Subject: [PATCH] Support partially mapped cbufs

Buggy games sometimes supply an incorrect cbuf size so limit buffers to the first unmapped region.
---
 app/src/main/cpp/skyline/common/span.h                       | 2 +-
 app/src/main/cpp/skyline/gpu/interconnect/graphics_context.h | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/app/src/main/cpp/skyline/common/span.h b/app/src/main/cpp/skyline/common/span.h
index 7aad8181..2904adf7 100644
--- a/app/src/main/cpp/skyline/common/span.h
+++ b/app/src/main/cpp/skyline/common/span.h
@@ -89,7 +89,7 @@ namespace skyline {
         /**
          * @return If the span is valid by not being null
          */
-        constexpr bool valid() {
+        constexpr bool valid() const {
             return this->data() != nullptr;
         }
 
diff --git a/app/src/main/cpp/skyline/gpu/interconnect/graphics_context.h b/app/src/main/cpp/skyline/gpu/interconnect/graphics_context.h
index 5e253c8f..9eb769d7 100644
--- a/app/src/main/cpp/skyline/gpu/interconnect/graphics_context.h
+++ b/app/src/main/cpp/skyline/gpu/interconnect/graphics_context.h
@@ -4,6 +4,7 @@
 #pragma once
 
 #include <boost/container/static_vector.hpp>
+#include <range/v3/algorithm.hpp>
 #include <gpu/texture/format.h>
 #include <gpu/buffer_manager.h>
 #include <soc/gm20b/channel.h>
@@ -603,6 +604,10 @@ namespace skyline::gpu::interconnect {
                 return constantBufferSelector;
 
             auto mappings{channelCtx.asCtx->gmmu.TranslateRange(constantBufferSelector.iova, constantBufferSelector.size)};
+
+            // Ignore unmapped areas from mappings due to buggy games setting the wrong cbuf size
+            mappings.erase(ranges::find_if(mappings, [](const auto &mapping) { return !mapping.valid(); }), mappings.end());
+
             constantBufferSelector.guest.mappings.assign(mappings.begin(), mappings.end());
 
             constantBufferSelector.view = gpu.buffer.FindOrCreate(constantBufferSelector.guest);