From 4dabb5d1f90f538c835ee72ca242171cb06d9dfa Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Sun, 19 Oct 2025 03:17:08 +0500
Subject: [PATCH] ref: gl: implement rotation for 2D

---
 ref/gl/gl_context.c |  7 ++-----
 ref/gl/gl_draw.c    | 21 +++++++++++++++++++--
 ref/gl/gl_local.h   |  2 ++
 3 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/ref/gl/gl_context.c b/ref/gl/gl_context.c
index db572995..53bf1235 100644
--- a/ref/gl/gl_context.c
+++ b/ref/gl/gl_context.c
@@ -365,11 +365,8 @@ static void GAME_EXPORT R_SetupSky( int *skyboxTextures )
 static qboolean R_SetDisplayTransform( ref_screen_rotation_t rotate, int offset_x, int offset_y, float scale_x, float scale_y )
 {
 	qboolean ret = true;
-	if( rotate > 0 )
-	{
-		gEngfuncs.Con_Printf("rotation transform not supported\n");
-		ret = false;
-	}
+
+	tr.rotation = rotate;
 
 	if( offset_x || offset_y )
 	{
diff --git a/ref/gl/gl_draw.c b/ref/gl/gl_draw.c
index cf6b4c1d..4fa6b65c 100644
--- a/ref/gl/gl_draw.c
+++ b/ref/gl/gl_draw.c
@@ -215,10 +215,27 @@ void R_Set2DMode( qboolean enable )
 			return;
 
 		// set 2D virtual screen size
-		pglViewport( 0, 0, gpGlobals->width, gpGlobals->height );
+		switch( tr.rotation )
+		{
+		case REF_ROTATE_CW:
+			pglViewport( 0, 0, gpGlobals->height, gpGlobals->width );
+			Matrix4x4_CreateOrtho( projection_matrix, 0, gpGlobals->height, gpGlobals->width, 0, -99999, 99999 );
+			Matrix4x4_ConcatRotate( projection_matrix, 90, 0, 0, 1 );
+			Matrix4x4_ConcatTranslate( projection_matrix, 0, -gpGlobals->height, 0 );
+			break;
+		case REF_ROTATE_CCW:
+			pglViewport( 0, 0, gpGlobals->height, gpGlobals->width );
+			Matrix4x4_CreateOrtho( projection_matrix, 0, gpGlobals->height, gpGlobals->width, 0, -99999, 99999 );
+			Matrix4x4_ConcatRotate( projection_matrix, -90, 0, 0, 1 );
+			Matrix4x4_ConcatTranslate( projection_matrix, -gpGlobals->width, 0, 0 );
+			break;
+		default:
+			pglViewport( 0, 0, gpGlobals->width, gpGlobals->height );
+			Matrix4x4_CreateOrtho( projection_matrix, 0, gpGlobals->width, gpGlobals->height, 0, -99999, 99999 );
+			break;
+		}
 
 		pglMatrixMode( GL_PROJECTION );
-		Matrix4x4_CreateOrtho( projection_matrix, 0, gpGlobals->width, gpGlobals->height, 0, -99999, 99999 );
 		GL_LoadMatrix( projection_matrix );
 
 		pglMatrixMode( GL_MODELVIEW );
diff --git a/ref/gl/gl_local.h b/ref/gl/gl_local.h
index bb4ad5bc..95b4df8e 100644
--- a/ref/gl/gl_local.h
+++ b/ref/gl/gl_local.h
@@ -263,6 +263,8 @@ typedef struct
 	uint *screengammatable;
 
 	uint max_entities;
+
+	ref_screen_rotation_t rotation;
 } gl_globals_t;
 
 typedef struct