renderer: add option "no_compute"

to forcibly disable the use of compute shaders

src/include/libplacebo/renderer.h

@@ -349,6 +349,10 @@ struct pl_render_params {
     // user, but it should be set to false once those values are "dialed in".
     bool dynamic_constants;
 
+    // Disables the use of compute shaders.
+    // Can improve power saving and (even) performance on certain GPUs.
+    bool no_compute;
+
     // This callback is invoked for every pass successfully executed in the
     // process of rendering a frame. Optional.
     //

src/options.c

@@ -1160,6 +1160,7 @@ const struct pl_opt_t pl_option_list[] = {
     OPT_BOOL("disable_fbos", "Disable FBOs", params.disable_fbos),
     OPT_BOOL("force_low_bit_depth_fbos", "Force 8-bit FBOs", params.force_low_bit_depth_fbos),
     OPT_BOOL("dynamic_constants", "Dynamic constants", params.dynamic_constants),
+    OPT_BOOL("no_compute", "Disable compute shaders", params.no_compute),
     {0},
 };
 

src/renderer.c

@@ -732,6 +732,10 @@ static void dispatch_sampler(struct pass_state *pass, pl_shader sh,
         fparams.no_compute = !(pass->fbofmt[4]->caps & PL_FMT_CAP_STORABLE);
     }
 
+    if (params->no_compute) {
+        fparams.no_compute = true;
+    }
+
     bool ok;
     if (info.config->polar) {
         // Polar samplers are always a single function call