From 5724bbd8e96a69e5ba3afd0ef4078855f0693807 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Wed, 3 May 2023 23:03:34 +0200
Subject: [PATCH] Correct size calculations in GLPushBuffer. I don't see how
 this failed as badly as in that crash report though...

---
 Common/GPU/OpenGL/GLRenderManager.cpp | 23 ++++++++++++++++++-----
 Common/GPU/OpenGL/GLRenderManager.h   |  1 +
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/Common/GPU/OpenGL/GLRenderManager.cpp b/Common/GPU/OpenGL/GLRenderManager.cpp
index da1efe7e2624..48b2f4dd339a 100644
--- a/Common/GPU/OpenGL/GLRenderManager.cpp
+++ b/Common/GPU/OpenGL/GLRenderManager.cpp
@@ -589,6 +589,7 @@ bool GLPushBuffer::AddBuffer() {
 	if (!info.localMemory)
 		return false;
 	info.buffer = render_->CreateBuffer(target_, size_, GL_DYNAMIC_DRAW);
+	info.size = size_;
 	buf_ = buffers_.size();
 	buffers_.push_back(info);
 	return true;
@@ -605,7 +606,6 @@ void GLPushBuffer::Destroy(bool onRenderThread) {
 		} else {
 			render_->DeleteBuffer(info.buffer);
 		}
-
 		FreeAlignedMemory(info.localMemory);
 	}
 	buffers_.clear();
@@ -652,18 +652,31 @@ void GLPushBuffer::Defragment() {
 	}
 
 	// Okay, we have more than one.  Destroy them all and start over with a larger one.
-	size_t newSize = size_ * buffers_.size();
+
+	// When calling AddBuffer, we sometimes increase size_. So if we allocated multiple buffers in a frame,
+	// they won't all have the same size. Sum things up properly.
+	size_t newSize = 0;
+	for (int i = 0; i < (int)buffers_.size(); i++) {
+		newSize += buffers_[i].size;
+	}
+
 	Destroy(false);
 
-	size_ = newSize;
+	// Set some sane but very free limits. If there's another spike, we'll just allocate more anyway.
+	size_ = std::min(std::max(newSize, (size_t)65536), (size_t)(512 * 1024 * 1024));
 	bool res = AddBuffer();
 	_assert_msg_(res, "AddBuffer failed");
 }
 
 size_t GLPushBuffer::GetTotalSize() const {
 	size_t sum = 0;
-	if (buffers_.size() > 1)
-		sum += size_ * (buffers_.size() - 1);
+	// When calling AddBuffer, we sometimes increase size_. So if we allocated multiple buffers in a frame,
+	// they won't all have the same size. Sum things up properly.
+	if (buffers_.size() > 1) {
+		for (int i = 0; i < (int)buffers_.size() - 1; i++) {
+			sum += buffers_[i].size;
+		}
+	}
 	sum += offset_;
 	return sum;
 }
diff --git a/Common/GPU/OpenGL/GLRenderManager.h b/Common/GPU/OpenGL/GLRenderManager.h
index 07f54ffab40c..f06724a6cbef 100644
--- a/Common/GPU/OpenGL/GLRenderManager.h
+++ b/Common/GPU/OpenGL/GLRenderManager.h
@@ -242,6 +242,7 @@ class GLPushBuffer {
 		uint8_t *localMemory = nullptr;
 		uint8_t *deviceMemory = nullptr;
 		size_t flushOffset = 0;
+		size_t size;
 	};
 
 	GLPushBuffer(GLRenderManager *render, GLuint target, size_t size);