vo_opengl: handle probing GL texture formats better

Retrieve the depth for each component and internal texture format
separately. Only for 8 bit per component textures we assume that all
bits are used (or else we would in my opinion create too many probe
textures).

Assuming 8 bit components are always correct also fixes operation in
GLES3, where we assumed that each component had -1 bits depth, and this
all UNORM formats were considered unusable. On GLES, the function to
check the real bit depth is not available. Since GLES has no 16 bit
UNORM textures at all, except with the MPGL_CAP_EXT16 extension, just
drop the special condition for it. (Of course GLES still manages to
introduce a funny special case by allowing GL_LUMINANCE , but not
defining GL_TEXTURE_LUMINANCE_SIZE.)

Should fix #4749.

video/out/opengl/gl_headers.h

@@ -37,6 +37,9 @@
 #define GL_RGBA12                         0x805A
 #define GL_RGBA16                         0x805B
 #define GL_TEXTURE_RED_SIZE               0x805C
+#define GL_TEXTURE_GREEN_SIZE             0x805D
+#define GL_TEXTURE_BLUE_SIZE              0x805E
+#define GL_TEXTURE_ALPHA_SIZE             0x805F
 
 // --- GL 1.1 (removed from 3.0 core and not in GLES 2/3)
 

video/out/opengl/gl_utils.c

@@ -335,35 +335,6 @@ void gl_pbo_upload_uninit(struct gl_pbo_upload *pbo)
     *pbo = (struct gl_pbo_upload){0};
 }
 
-// The intention is to return the actual depth of any fixed point 16 bit
-// textures. (Actually tests only 1 format - hope that is good enough.)
-int gl_determine_16bit_tex_depth(GL *gl)
-{
-    const struct gl_format *fmt = gl_find_unorm_format(gl, 2, 1);
-    if (!gl->GetTexLevelParameteriv || !fmt) {
-        // ANGLE supports ES 3.0 and the extension, but lacks the function above.
-        if (gl->mpgl_caps & MPGL_CAP_EXT16)
-            return 16;
-        return -1;
-    }
-
-    GLuint tex;
-    gl->GenTextures(1, &tex);
-    gl->BindTexture(GL_TEXTURE_2D, tex);
-    gl->TexImage2D(GL_TEXTURE_2D, 0, fmt->internal_format, 64, 64, 0,
-                   fmt->format, fmt->type, NULL);
-    GLenum pname = 0;
-    switch (fmt->format) {
-    case GL_RED:        pname = GL_TEXTURE_RED_SIZE; break;
-    case GL_LUMINANCE:  pname = GL_TEXTURE_LUMINANCE_SIZE; break;
-    }
-    GLint param = -1;
-    if (pname)
-        gl->GetTexLevelParameteriv(GL_TEXTURE_2D, 0, pname, &param);
-    gl->DeleteTextures(1, &tex);
-    return param;
-}
-
 int gl_get_fb_depth(GL *gl, int fbo)
 {
     if ((gl->es < 300 && !gl->version) || !(gl->mpgl_caps & MPGL_CAP_FB))

video/out/opengl/gl_utils.h

@@ -66,7 +66,6 @@ void gl_pbo_upload_tex(struct gl_pbo_upload *pbo, GL *gl, bool use_pbo,
                        int x, int y, int w, int h);
 void gl_pbo_upload_uninit(struct gl_pbo_upload *pbo);
 
-int gl_determine_16bit_tex_depth(GL *gl);
 int gl_get_fb_depth(GL *gl, int fbo);
 
 #endif

video/out/opengl/ra_gl.c

@@ -41,6 +41,42 @@ struct ra_renderpass_gl {
     struct gl_vao vao;
 };
 
+// (Init time only.)
+static void probe_real_size(GL *gl, struct ra_format *fmt)
+{
+    const struct gl_format *gl_fmt = fmt->priv;
+
+    if (!gl->GetTexLevelParameteriv)
+        return; // GLES
+
+    bool is_la = gl_fmt->format == GL_LUMINANCE ||
+                 gl_fmt->format == GL_LUMINANCE_ALPHA;
+    if (is_la && gl->es)
+        return; // GLES doesn't provide GL_TEXTURE_LUMINANCE_SIZE.
+
+    GLuint tex;
+    gl->GenTextures(1, &tex);
+    gl->BindTexture(GL_TEXTURE_2D, tex);
+    gl->TexImage2D(GL_TEXTURE_2D, 0, gl_fmt->internal_format, 64, 64, 0,
+                   gl_fmt->format, gl_fmt->type, NULL);
+    for (int i = 0; i < fmt->num_components; i++) {
+        const GLenum pnames[] = {
+            GL_TEXTURE_RED_SIZE,
+            GL_TEXTURE_GREEN_SIZE,
+            GL_TEXTURE_BLUE_SIZE,
+            GL_TEXTURE_ALPHA_SIZE,
+            GL_TEXTURE_LUMINANCE_SIZE,
+            GL_TEXTURE_ALPHA_SIZE,
+        };
+        int comp = is_la ? i + 4 : i;
+        assert(comp < MP_ARRAY_SIZE(pnames));
+        GLint param = -1;
+        gl->GetTexLevelParameteriv(GL_TEXTURE_2D, 0, pnames[comp], &param);
+        fmt->component_depth[i] = param > 0 ? param : 0;
+    }
+    gl->DeleteTextures(1, &tex);
+}
+
 static int ra_init_gl(struct ra *ra, GL *gl)
 {
     if (gl->version < 210 && gl->es < 200) {
@@ -74,10 +110,6 @@ static int ra_init_gl(struct ra *ra, GL *gl)
 
     int gl_fmt_features = gl_format_feature_flags(gl);
 
-    // Test whether we can use 10 bit.
-    int depth16 = gl_determine_16bit_tex_depth(gl);
-    MP_VERBOSE(ra, "16 bit texture depth: %d.\n", depth16);
-
     for (int n = 0; gl_formats[n].internal_format; n++) {
         const struct gl_format *gl_fmt = &gl_formats[n];
 
@@ -100,8 +132,7 @@ static int ra_init_gl(struct ra *ra, GL *gl)
 
         int csize = gl_component_size(gl_fmt->type) * 8;
         int depth = csize;
-        if (fmt->ctype == RA_CTYPE_UNORM)
-            depth = MPMIN(csize, depth16); // naive/approximate
+
         if (gl_fmt->flags & F_F16) {
             depth = 16;
             csize = 32; // always upload as GL_FLOAT (simpler for us)
@@ -112,6 +143,9 @@ static int ra_init_gl(struct ra *ra, GL *gl)
             fmt->component_depth[i] = depth;
         }
 
+        if (fmt->ctype == RA_CTYPE_UNORM && depth != 8)
+            probe_real_size(gl, fmt);
+
         // Special formats for which OpenGL happens to have direct support.
         if (strcmp(fmt->name, "rgb565") == 0) {
             fmt->special_imgfmt = IMGFMT_RGB565;
@@ -149,6 +183,9 @@ static int ra_init_gl(struct ra *ra, GL *gl)
 
     gl->Disable(GL_DITHER);
 
+    if (!ra_find_unorm_format(ra, 2, 1))
+        MP_VERBOSE(ra, "16 bit UNORM textures not available.\n");
+
     return 0;
 }