From a055d07fc558c88d13fbcaa29a63ba08410a57f6 Mon Sep 17 00:00:00 2001
From: Dima353 <75039669+Dima353@users.noreply.github.com>
Date: Tue, 21 Jul 2026 22:38:51 +0300
Subject: [PATCH] gl3: orphan im2D/im3D buffers at actual size on Switch

---
 src/gl/gl3immed.cpp | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/gl/gl3immed.cpp b/src/gl/gl3immed.cpp
index 3b4aae4..c8631d2 100644
--- a/src/gl/gl3immed.cpp
+++ b/src/gl/gl3immed.cpp
@@ -133,8 +133,19 @@ im2DRenderPrimitive(PrimitiveType primType, void *vertices, int32 numVertices)
 #endif
 
 	glBindBuffer(GL_ARRAY_BUFFER, im2DVbo);
+#ifdef __SWITCH__
+	// Orphan with exactly the size we need, in one call that also uploads.
+	// The stock path orphans the whole STARTVERTICES buffer (~240KB) on every
+	// single 2D draw - even a 4-vertex sprite - and hundreds of those per frame
+	// exhaust nouveau's buffer allocator. It then hands back a buffer with no
+	// backing store and glBufferSubData memcpy's into null (Data Abort at 0).
+	// Orphaning itself must stay: without it the GPU may still be reading the
+	// buffer we overwrite, which mixes geometry between draws.
+	glBufferData(GL_ARRAY_BUFFER, numVertices*sizeof(Im2DVertex), vertices, GL_STREAM_DRAW);
+#else
 	glBufferData(GL_ARRAY_BUFFER, STARTVERTICES*sizeof(Im2DVertex), nil, GL_STREAM_DRAW);
 	glBufferSubData(GL_ARRAY_BUFFER, 0, numVertices*sizeof(Im2DVertex), vertices);
+#endif
 
 	if(im2dOverrideShader)
 		im2dOverrideShader->use();
@@ -163,12 +174,20 @@ im2DRenderIndexedPrimitive(PrimitiveType primType,
 #endif
 
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, im2DIbo);
+#ifdef __SWITCH__
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, numIndices*2, indices, GL_STREAM_DRAW);
+#else
 	glBufferData(GL_ELEMENT_ARRAY_BUFFER, STARTINDICES*2, nil, GL_STREAM_DRAW);
 	glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, numIndices*2, indices);
+#endif
 
 	glBindBuffer(GL_ARRAY_BUFFER, im2DVbo);
+#ifdef __SWITCH__
+	glBufferData(GL_ARRAY_BUFFER, numVertices*sizeof(Im2DVertex), vertices, GL_STREAM_DRAW);
+#else
 	glBufferData(GL_ARRAY_BUFFER, STARTVERTICES*sizeof(Im2DVertex), nil, GL_STREAM_DRAW);
 	glBufferSubData(GL_ARRAY_BUFFER, 0, numVertices*sizeof(Im2DVertex), vertices);
+#endif
 
 	if(im2dOverrideShader)
 		im2dOverrideShader->use();
@@ -263,8 +282,12 @@ im3DTransform(void *vertices, int32 numVertices, Matrix *world, uint32 flags)
 #endif
 
 	glBindBuffer(GL_ARRAY_BUFFER, im3DVbo);
+#ifdef __SWITCH__
+	glBufferData(GL_ARRAY_BUFFER, numVertices*sizeof(Im3DVertex), vertices, GL_STREAM_DRAW);
+#else
 	glBufferData(GL_ARRAY_BUFFER, STARTVERTICES*sizeof(Im3DVertex), nil, GL_STREAM_DRAW);
 	glBufferSubData(GL_ARRAY_BUFFER, 0, numVertices*sizeof(Im3DVertex), vertices);
+#endif
 #ifndef RW_GL_USE_VAOS
 	setAttribPointers(im3dattribDesc, 3);
 #endif
@@ -284,8 +307,12 @@ void
 im3DRenderIndexedPrimitive(PrimitiveType primType, void *indices, int32 numIndices)
 {
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, im3DIbo);
+#ifdef __SWITCH__
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, numIndices*2, indices, GL_STREAM_DRAW);
+#else
 	glBufferData(GL_ELEMENT_ARRAY_BUFFER, STARTINDICES*2, nil, GL_STREAM_DRAW);
 	glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, numIndices*2, indices);
+#endif
 
 	flushCache();
 	glDrawElements(primTypeMap[primType], numIndices,