From af50403e5084ebbeaedad09771e57b11d2a47734 Mon Sep 17 00:00:00 2001 From: Sam Lantinga Date: Sun, 15 Jun 2014 18:09:39 -0700 Subject: [PATCH] Fixed bug 2575 - Current GL context tracking fails Ronie Salgado The GL Renderer current context tracking fails when one window is used with an SDL renderer but another separate window is used with a user handled OpenGL context. Attached is a small program that reproduces this bug, at least in some Linux machines where an OpenGL renderer is provided by default. Expected Output: -"First window" should be blue. -"Second window" should be green. Gotten Output: - "First window" black. - "Second window" blue. What happened: The renderer created for the "first window" ends rendering into the "second window" OpenGL context. Bug location: SDL_render_gl.c - line 286 on hg: static SDL_GLContext SDL_CurrentContext = NULL; When making SDL_GL_MakeCurrent from the user perspective, that variable or the GL renderer is not notified about the OpenGL context change. Solution proposal: - Move the current GL context cache into another place global. --- src/render/opengl/SDL_render_gl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/src/render/opengl/SDL_render_gl.c b/src/render/opengl/SDL_render_gl.c index 643f2488a..f8fe0c4b5 100644 --- a/src/render/opengl/SDL_render_gl.c +++ b/src/render/opengl/SDL_render_gl.c @@ -290,7 +290,8 @@ GL_ActivateRenderer(SDL_Renderer * renderer) { GL_RenderData *data = (GL_RenderData *) renderer->driverdata; - if (SDL_CurrentContext != data->context) { + if (SDL_CurrentContext != data->context || + SDL_GL_GetCurrentContext() != data->context) { if (SDL_GL_MakeCurrent(renderer->window, data->context) < 0) { return -1; } @@ -310,7 +311,7 @@ GL_ResetState(SDL_Renderer *renderer) { GL_RenderData *data = (GL_RenderData *) renderer->driverdata; - if (SDL_CurrentContext == data->context) { + if (SDL_GL_GetCurrentContext() == data->context) { GL_UpdateViewport(renderer); } else { GL_ActivateRenderer(renderer);