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.

1 files changed, 43 insertions, 6 deletions

diff --git a/video/out/opengl/ra_gl.c b/video/out/opengl/ra_gl.c
index fbde3c81d4..5f8c525f5b 100644
--- a/video/out/opengl/ra_gl.c
+++ b/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;
 }