opengl/context: disable SSBO on GLSL < 140

The layout of variables inside an SSBO is implementation-defined making
it not really safe to use without layout specification, which is
supported on GLSL >= 140.

src/opengl/context.c

@@ -300,6 +300,12 @@ pl_opengl pl_opengl_create(pl_log log, const struct pl_opengl_params *params)
                 params->max_glsl_version, glsl->version);
     }
 
+    // The layout of variables inside an SSBO is implementation-defined,
+    // disable SSBO if layout qualifier is not supported.
+    struct pl_gpu_t *gpu = (struct pl_gpu_t *) pl_gl->gpu;
+    if (gpu->glsl.version < 140)
+        gpu->limits.max_ssbo_size = 0;
+
     gl_release_current(pl_gl);
     return pl_gl;
 

src/tests/gpu_tests.h

@@ -76,9 +76,7 @@ static void pl_buffer_tests(pl_gpu gpu)
     }
 
     // `compute_queues` check is to exclude dummy GPUs here
-    if (buf_size <= gpu->limits.max_ssbo_size &&
-        gpu->limits.compute_queues &&
-        gpu->glsl.version >= 130)
+    if (buf_size <= gpu->limits.max_ssbo_size && gpu->limits.compute_queues)
     {
         printf("test endian swapping\n");
         buf = pl_buf_create(gpu, pl_buf_params(
@@ -1158,7 +1156,7 @@ static void pl_render_tests(pl_gpu gpu)
         hook = pl_mpv_user_shader_parse(gpu, user_shader_tests[i],
                                         strlen(user_shader_tests[i]));
 
-        if (gpu->glsl.compute) {
+        if (gpu->glsl.compute && gpu->limits.max_ssbo_size) {
             REQUIRE(hook);
         } else {
             // Not all shaders compile without compute shader support