vo_opengl: always premultiply alpha

Until now, we've let the windowing backend decide. But since they
usually require premultiplied alpha, and premultiplied alpha is easier
to handle, hardcode it.

4 files changed, 1 insertions, 5 deletions

diff --git a/video/out/opengl/common.h b/video/out/opengl/common.h
index 9236ce1d6f..f790dcb166 100644
--- a/video/out/opengl/common.h
+++ b/video/out/opengl/common.h
@@ -89,7 +89,6 @@ struct GL {
     int mpgl_caps;              // Bitfield of MPGL_CAP_* constants
     bool debug_context;         // use of e.g. GLX_CONTEXT_DEBUG_BIT_ARB
     int fb_r, fb_g, fb_b;       // frame buffer bit depth (0 if unknown)
-    bool fb_premultiplied;      // assumption about FB alpha compositor usage
 
     void (GLAPIENTRY *Viewport)(GLint, GLint, GLsizei, GLsizei);
     void (GLAPIENTRY *Clear)(GLbitfield);
diff --git a/video/out/opengl/context_cocoa.c b/video/out/opengl/context_cocoa.c
index e48472ff46..271bdb7444 100644
--- a/video/out/opengl/context_cocoa.c
+++ b/video/out/opengl/context_cocoa.c
@@ -124,7 +124,6 @@ static bool create_gl_context(struct MPGLContext *ctx, int vo_flags)
 
     mpgl_load_functions(ctx->gl, (void *)cocoa_glgetaddr, NULL, ctx->vo->log);
     ctx->gl->fb_r = ctx->gl->fb_g = ctx->gl->fb_b = cgl_color_size(ctx);
-    ctx->gl->fb_premultiplied = true;
 
     CGLReleasePixelFormat(p->pix);
 
diff --git a/video/out/opengl/context_x11.c b/video/out/opengl/context_x11.c
index c02730c729..d9a584e87c 100644
--- a/video/out/opengl/context_x11.c
+++ b/video/out/opengl/context_x11.c
@@ -274,7 +274,6 @@ static int glx_init(struct MPGLContext *ctx, int flags)
     glXGetFBConfigAttrib(vo->x11->display, fbc, GLX_RED_SIZE, &ctx->gl->fb_r);
     glXGetFBConfigAttrib(vo->x11->display, fbc, GLX_GREEN_SIZE, &ctx->gl->fb_g);
     glXGetFBConfigAttrib(vo->x11->display, fbc, GLX_BLUE_SIZE, &ctx->gl->fb_b);
-    ctx->gl->fb_premultiplied = true;
 
     return 0;
 
diff --git a/video/out/opengl/video.c b/video/out/opengl/video.c
index de9fdd2814..6b46c1fb42 100644
--- a/video/out/opengl/video.c
+++ b/video/out/opengl/video.c
@@ -1736,8 +1736,7 @@ static void pass_convert_yuv(struct gl_video *p)
         GLSL(color.rgb = color.rgb * color.a + background * (1.0 - color.a);)
     } else { // alpha present in image
         p->components = 4;
-        if (p->gl->fb_premultiplied)
-            GLSL(color = vec4(color.rgb * color.a, color.a);)
+        GLSL(color = vec4(color.rgb * color.a, color.a);)
     }
 }