From d9290f2e0364208d8599d58cb99aeebbcf32d382 Mon Sep 17 00:00:00 2001
From: mittorn <mittorn@sibmail.com>
Date: Tue, 7 Jul 2020 00:23:23 +0700
Subject: [PATCH] gles1 and non-pbo fallbacks

---
 ref_soft/r_glblit.c | 52 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 46 insertions(+), 6 deletions(-)

diff --git a/ref_soft/r_glblit.c b/ref_soft/r_glblit.c
index a46ef98d..a6bd2f83 100644
--- a/ref_soft/r_glblit.c
+++ b/ref_soft/r_glblit.c
@@ -11,6 +11,7 @@ struct swblit_s
 	void (*pUnlockBuffer)( void );
 	qboolean(*pCreateBuffer)( int width, int height, uint *stride, uint *bpp, uint *r, uint *g, uint *b );
 	uint rotate;
+	qboolean gl1;
 } swblit;
 
 
@@ -92,8 +93,18 @@ void GAME_EXPORT GL_SetupAttributes( int safegl )
 	// untill we have any blitter in ref api, setup GL
 	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_PROFILE_MASK, REF_GL_CONTEXT_PROFILE_ES );
 	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_EGL, 1 );
-	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MAJOR_VERSION, 3 );
-	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MINOR_VERSION, 0 );
+//	safegl=1;
+	if( safegl )
+	{
+		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MAJOR_VERSION, 1 );
+		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MINOR_VERSION, 1 );
+		swblit.gl1 = true;
+	}
+	else
+	{
+		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MAJOR_VERSION, 3 );
+		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MINOR_VERSION, 0 );
+	}
 	gEngfuncs.GL_SetAttribute( REF_GL_DOUBLEBUFFER, 1 );
 
 	gEngfuncs.GL_SetAttribute( REF_GL_RED_SIZE, 5 );
@@ -293,16 +304,39 @@ static qboolean R_CreateBuffer_GLES1( int width, int height, uint *stride, uint
 
 static void *R_Lock_GLES3( void )
 {
+	void *buf;
+
+	if( !vid.width || !vid.height )
+		return NULL;
+
+	if( glbuf )
+		return glbuf;
+
 	pglBufferData( GL_PIXEL_UNPACK_BUFFER, vid.width * vid.height * 2, 0, GL_STREAM_DRAW_ARB );
-	return pglMapBuffer( GL_PIXEL_UNPACK_BUFFER, GL_WRITE_ONLY_ARB );
+	buf = pglMapBuffer( GL_PIXEL_UNPACK_BUFFER, GL_WRITE_ONLY_ARB );
+	if( !buf )
+	{
+		pglUnmapBuffer( GL_PIXEL_UNPACK_BUFFER );
+		pglBindBuffer( GL_PIXEL_UNPACK_BUFFER, 0 );
+		glbuf = Mem_Malloc( r_temppool, vid.width*vid.height*2 );
+		pglTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vid.width, vid.height, 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, glbuf );
+		return glbuf;
+	}
+	else
+		return buf;
 }
 
 
 static void R_Unlock_GLES3( void )
 {
 	gEngfuncs.GL_SwapBuffers();
-	pglUnmapBuffer( GL_PIXEL_UNPACK_BUFFER );
-	pglTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vid.width, vid.height, 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, 0 );
+	if( glbuf )
+		pglTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vid.width, vid.height, 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, glbuf );
+	else
+	{
+		pglUnmapBuffer( GL_PIXEL_UNPACK_BUFFER );
+		pglTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vid.width, vid.height, 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, 0 );
+	}
 	//pglDrawArrays( GL_TRIANGLE_FAN, 0,4 );
 	pglBlitFramebuffer( 0, vid.height, vid.width, 0, 0, 0, vid.width, vid.height, GL_COLOR_BUFFER_BIT, GL_NEAREST );
 }
@@ -591,7 +625,13 @@ void R_InitBlit( qboolean glblit )
 {
 	R_BuildBlendMaps();
 
-	if( glblit )
+	if( glblit && swblit.gl1 )
+	{
+		swblit.pLockBuffer = R_Lock_GL1;
+		swblit.pUnlockBuffer = R_Unlock_GLES1;
+		swblit.pCreateBuffer = R_CreateBuffer_GLES1;
+	}
+	else if( glblit )
 	{
 		swblit.pLockBuffer = R_Lock_GLES3;
 		swblit.pUnlockBuffer = R_Unlock_GLES3;