vo_opengl: use standard functions to retrieve display depth

Until now, we've used system-specific API (GLX, EGL, etc.) to retrieve
the depth of the default framebuffer. (We equal this to display depth
and use the determined depth for dithering.)

We can actually retrieve this value through standard GL API, and it
works everywhere (except GLES 2 of course). This simplifies everything a
great deal.

egl_helpers.c is empty now. But I expect that some EGL boilerplate will
be moved to it, so don't remove it yet.

10 files changed, 21 insertions, 59 deletions

diff --git a/video/out/opengl/common.c b/video/out/opengl/common.c
index dd9ecc46fa..702f473ba2 100644
--- a/video/out/opengl/common.c
+++ b/video/out/opengl/common.c
@@ -214,6 +214,7 @@ static const struct gl_functions gl_functions[] = {
             DEF_FN(DeleteFramebuffers),
             DEF_FN(CheckFramebufferStatus),
             DEF_FN(FramebufferTexture2D),
+            DEF_FN(GetFramebufferAttachmentParameteriv),
             {0}
         },
     },
diff --git a/video/out/opengl/common.h b/video/out/opengl/common.h
index ea5442b4ff..7427befe99 100644
--- a/video/out/opengl/common.h
+++ b/video/out/opengl/common.h
@@ -91,7 +91,6 @@ struct GL {
     char *extensions;           // Equivalent to GL_EXTENSIONS
     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)
 
     void (GLAPIENTRY *Viewport)(GLint, GLint, GLsizei, GLsizei);
     void (GLAPIENTRY *Clear)(GLbitfield);
@@ -169,6 +168,8 @@ struct GL {
                                             GLint);
     void (GLAPIENTRY *BlitFramebuffer)(GLint, GLint, GLint, GLint, GLint, GLint,
                                        GLint, GLint, GLbitfield, GLenum);
+    void (GLAPIENTRY *GetFramebufferAttachmentParameteriv)(GLenum, GLenum,
+                                                           GLenum, GLint *);
 
     void (GLAPIENTRY *Uniform1f)(GLint, GLfloat);
     void (GLAPIENTRY *Uniform2f)(GLint, GLfloat, GLfloat);
diff --git a/video/out/opengl/context_cocoa.c b/video/out/opengl/context_cocoa.c
index 271bdb7444..ea7a9b535f 100644
--- a/video/out/opengl/context_cocoa.c
+++ b/video/out/opengl/context_cocoa.c
@@ -33,14 +33,6 @@ static int set_swap_interval(int enabled)
     return (err == kCGLNoError) ? 0 : -1;
 }
 
-static int cgl_color_size(struct MPGLContext *ctx)
-{
-    struct cgl_context *p = ctx->priv;
-    GLint value;
-    CGLDescribePixelFormat(p->pix, 0, kCGLPFAColorSize, &value);
-    return value > 16 ? 8 : 5;
-}
-
 static void *cocoa_glgetaddr(const char *s)
 {
     void *ret = NULL;
@@ -123,7 +115,6 @@ static bool create_gl_context(struct MPGLContext *ctx, int vo_flags)
         CGLSetParameter(p->ctx, kCGLCPSurfaceOpacity, &(GLint){0});
 
     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);
 
     CGLReleasePixelFormat(p->pix);
 
diff --git a/video/out/opengl/context_dxinterop.c b/video/out/opengl/context_dxinterop.c
index a4dc165132..4f75d22186 100644
--- a/video/out/opengl/context_dxinterop.c
+++ b/video/out/opengl/context_dxinterop.c
@@ -278,25 +278,6 @@ static int d3d_size_dependent_create(MPGLContext *ctx)
     MP_VERBOSE(ctx->vo, "DX_interop backbuffer format: %u\n",
         (unsigned)bb_desc.Format);
 
-    // Note: This backend has only been tested on an 8-bit display. It's
-    // unknown whether this code is enough to support other formats or if more
-    // work is needed.
-    switch (bb_desc.Format) {
-    case D3DFMT_X1R5G5B5: case D3DFMT_A1R5G5B5:
-        ctx->gl->fb_r = ctx->gl->fb_g = ctx->gl->fb_b = 5;
-        break;
-    case D3DFMT_R5G6B5:
-        ctx->gl->fb_r = 5; ctx->gl->fb_g = 6; ctx->gl->fb_b = 5;
-        break;
-    case D3DFMT_R8G8B8: case D3DFMT_A8R8G8B8: case D3DFMT_X8R8G8B8:
-    case D3DFMT_A8B8G8R8: case D3DFMT_X8B8G8R8: default:
-        ctx->gl->fb_r = ctx->gl->fb_g = ctx->gl->fb_b = 8;
-        break;
-    case D3DFMT_A2R10G10B10: case D3DFMT_A2B10G10R10:
-        ctx->gl->fb_r = ctx->gl->fb_g = ctx->gl->fb_b = 10;
-        break;
-    }
-
     // Create a rendertarget with the same format as the backbuffer for
     // rendering from OpenGL
     HANDLE share_handle = NULL;
diff --git a/video/out/opengl/context_w32.c b/video/out/opengl/context_w32.c
index c647d97e5c..3a0118e420 100644
--- a/video/out/opengl/context_w32.c
+++ b/video/out/opengl/context_w32.c
@@ -209,14 +209,6 @@ static void create_ctx(void *ptr)
     if (!w32_ctx->context)
         create_context_w32_old(ctx);
 
-    int pfmt = GetPixelFormat(w32_ctx->hdc);
-    PIXELFORMATDESCRIPTOR pfd;
-    if (DescribePixelFormat(w32_ctx->hdc, pfmt, sizeof(pfd), &pfd)) {
-        ctx->gl->fb_r = pfd.cRedBits;
-        ctx->gl->fb_g = pfd.cGreenBits;
-        ctx->gl->fb_b = pfd.cBlueBits;
-    }
-
     wglMakeCurrent(w32_ctx->hdc, NULL);
 }
 
diff --git a/video/out/opengl/context_x11.c b/video/out/opengl/context_x11.c
index d9a584e87c..11700efdf4 100644
--- a/video/out/opengl/context_x11.c
+++ b/video/out/opengl/context_x11.c
@@ -271,10 +271,6 @@ static int glx_init(struct MPGLContext *ctx, int flags)
     if (!success)
         goto uninit;
 
-    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);
-
     return 0;
 
 uninit:
diff --git a/video/out/opengl/context_x11egl.c b/video/out/opengl/context_x11egl.c
index 14ca3f9e25..2e4fd5fa90 100644
--- a/video/out/opengl/context_x11egl.c
+++ b/video/out/opengl/context_x11egl.c
@@ -163,7 +163,6 @@ static int mpegl_init(struct MPGLContext *ctx, int flags)
 
     void *(*gpa)(const GLubyte*) = (void *(*)(const GLubyte*))eglGetProcAddress;
     mpgl_load_functions(ctx->gl, gpa, egl_exts, vo->log);
-    mp_egl_get_depth(ctx->gl, config);
 
     ctx->native_display_type = "x11";
     ctx->native_display = vo->x11->display;
diff --git a/video/out/opengl/egl_helpers.c b/video/out/opengl/egl_helpers.c
index d86b5becde..7e236f1da9 100644
--- a/video/out/opengl/egl_helpers.c
+++ b/video/out/opengl/egl_helpers.c
@@ -18,13 +18,3 @@
 #include "egl_helpers.h"
 #include "common.h"
 
-void mp_egl_get_depth(struct GL *gl, EGLConfig fbc)
-{
-    EGLint tokens[] = {EGL_RED_SIZE, EGL_GREEN_SIZE, EGL_BLUE_SIZE};
-    int *ptrs[] =     {&gl->fb_r,    &gl->fb_g,      &gl->fb_b};
-    for (int n = 0; n < MP_ARRAY_SIZE(tokens); n++) {
-        EGLint depth = 0;
-        if (eglGetConfigAttrib(eglGetCurrentDisplay(), fbc, tokens[n], &depth))
-            *ptrs[n] = depth;
-    }
-}
diff --git a/video/out/opengl/egl_helpers.h b/video/out/opengl/egl_helpers.h
index f9961fee48..3806ef1d35 100644
--- a/video/out/opengl/egl_helpers.h
+++ b/video/out/opengl/egl_helpers.h
@@ -4,7 +4,4 @@
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
 
-struct GL;
-void mp_egl_get_depth(struct GL *gl, EGLConfig fbc);
-
 #endif
diff --git a/video/out/opengl/video.c b/video/out/opengl/video.c
index c9179c7800..961eab3383 100644
--- a/video/out/opengl/video.c
+++ b/video/out/opengl/video.c
@@ -180,6 +180,7 @@ struct gl_video {
     bool gl_debug;
 
     int texture_16bit_depth;    // actual bits available in 16 bit textures
+    int fb_depth;               // actual bits available in GL main framebuffer
 
     struct gl_shader_cache *sc;
 
@@ -2377,7 +2378,7 @@ static void pass_dither(struct gl_video *p)
     GL *gl = p->gl;
 
     // Assume 8 bits per component if unknown.
-    int dst_depth = gl->fb_g ? gl->fb_g : 8;
+    int dst_depth = p->fb_depth;
     if (p->opts.dither_depth > 0)
         dst_depth = p->opts.dither_depth;
 
@@ -3310,9 +3311,6 @@ static void init_gl(struct gl_video *p)
 
     debug_check_gl(p, "before init_gl");
 
-    MP_VERBOSE(p, "Reported display depth: R=%d, G=%d, B=%d\n",
-               gl->fb_r, gl->fb_g, gl->fb_b);
-
     gl->Disable(GL_DITHER);
 
     gl_vao_init(&p->vao, gl, sizeof(struct vertex), vertex_vao);
@@ -3343,6 +3341,22 @@ static void init_gl(struct gl_video *p)
         gl->DeleteTextures(1, &tex);
     }
 
+    if ((gl->es >= 300 || gl->version) && (gl->mpgl_caps & MPGL_CAP_FB)) {
+        GLint depth_r = -1, depth_g = -1, depth_b = -1;
+
+        gl->GetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_BACK,
+                            GL_FRAMEBUFFER_ATTACHMENT_RED_SIZE, &depth_r);
+        gl->GetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_BACK,
+                            GL_FRAMEBUFFER_ATTACHMENT_GREEN_SIZE, &depth_g);
+        gl->GetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_BACK,
+                            GL_FRAMEBUFFER_ATTACHMENT_BLUE_SIZE, &depth_b);
+
+        MP_VERBOSE(p, "Reported display depth: R=%d, G=%d, B=%d\n",
+                   depth_r, depth_g, depth_b);
+
+        p->fb_depth = depth_g > 0 ? depth_g : 8;
+    }
+
     p->upload_timer = gl_timer_create(p->gl);
     p->render_timer = gl_timer_create(p->gl);
     p->present_timer = gl_timer_create(p->gl);