From 4954518125d6cc61af3302c0db7487025e0e37e6 Mon Sep 17 00:00:00 2001 From: Neil Roberts Date: Fri, 7 Mar 2014 18:05:45 +0000 Subject: [PATCH] Fix the initial value of glDrawBuffers for GLES MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Under GLES 3 it is not valid to pass GL_FRONT to glDrawBuffers. Instead, GL_BACK has a magic interpretation which means it will render to the front buffer on single-buffered contexts and the back buffer on double-buffered. We were incorrectly setting the initial value to GL_FRONT for single-buffered contexts. This probably doesn't really matter at the moment except that presumably it would be exposed in the API via glGetIntegerv. When we switch to configless contexts this is more important because in that case we always want to rely on the magic interpretation of GL_BACK in order to automatically switch between the front and back buffer when a new surface with a different number of buffers is bound. We also do this for GLES 1 and 2 because the internal value doesn't matter in that case and it is convenient to use the same code to have the magic interpretation of GL_BACK. Reviewed-by: Kristian Høgsberg --- src/mesa/main/blend.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/mesa/main/blend.c b/src/mesa/main/blend.c index eb4f1d6bef2..c37c0fea52b 100644 --- a/src/mesa/main/blend.c +++ b/src/mesa/main/blend.c @@ -911,7 +911,9 @@ void _mesa_init_color( struct gl_context * ctx ) ctx->Color.LogicOp = GL_COPY; ctx->Color.DitherFlag = GL_TRUE; - if (ctx->Visual.doubleBufferMode) { + /* GL_FRONT is not possible on GLES. Instead GL_BACK will render to either + * the front or the back buffer depending on the config */ + if (ctx->Visual.doubleBufferMode || _mesa_is_gles(ctx)) { ctx->Color.DrawBuffer[0] = GL_BACK; } else { -- 2.30.2