Increase dither noise strength at higher resolutions to make it more noticeable

include/rt64_layer.h

@@ -32,6 +32,7 @@ namespace ultramodern {
             void shutdown();
             void set_dummy_vi();
             uint32_t get_display_framerate();
+            float get_resolution_scale();
             void load_shader_cache(std::span<const char> cache_binary);
         private:
             RT64SetupResult setup_result;

patches/effect_patches.c

@@ -106,6 +106,12 @@ void Play_DrawMotionBlur(PlayState* this) {
         }
         alpha = (s32)(alpha_float * 255.0f);
 
+        // @recomp Set the dither noise strength based on the resolution scale to make it easier to see at higher resolutions.
+        float res_scale = recomp_get_resolution_scale();
+        float dither_noise_strength = CLAMP(1.0 + (res_scale - 1.0f) / 8.0f, 1.0f, 2.0f);
+        // recomp_printf("res scale: %5.3f   dither noise strength: %5.3f\n", res_scale, dither_noise_strength);
+        gEXSetDitherNoiseStrength(OVERLAY_DISP++, dither_noise_strength);
+
         if (sMotionBlurStatus == MOTION_BLUR_PROCESS) {
             func_80170AE0(&this->pauseBgPreRender, &gfx, alpha);
         } else {

patches/graphics.h

@@ -6,5 +6,6 @@
 DECLARE_FUNC(float, recomp_get_aspect_ratio, float);
 DECLARE_FUNC(s32, recomp_get_target_framerate, s32);
 DECLARE_FUNC(s32, recomp_high_precision_fb_enabled);
+DECLARE_FUNC(float, recomp_get_resolution_scale);
 
 #endif

patches/syms.ld

@@ -53,3 +53,4 @@ recomp_autosave_enabled = 0x8F00008C;
 recomp_load_overlays = 0x8F000090;
 osInvalICache_recomp = 0x8F000094;
 recomp_high_precision_fb_enabled = 0x8F0000A8;
+recomp_get_resolution_scale = 0x8F0000AC;

src/game/recomp_api.cpp

@@ -107,3 +107,7 @@ extern "C" void recomp_load_overlays(uint8_t * rdram, recomp_context * ctx) {
 extern "C" void recomp_high_precision_fb_enabled(uint8_t * rdram, recomp_context * ctx) {
     _return(ctx, static_cast<s32>(ultramodern::RT64HighPrecisionFBEnabled()));
 }
+
+extern "C" void recomp_get_resolution_scale(uint8_t* rdram, recomp_context* ctx) {
+    _return(ctx, ultramodern::get_resolution_scale());
+}

ultramodern/events.cpp

@@ -279,6 +279,7 @@ ultramodern::GraphicsConfig ultramodern::get_graphics_config() {
 }
 
 std::atomic_uint32_t display_refresh_rate = 60;
+std::atomic<float> resolution_scale = 1.0f;
 
 uint32_t ultramodern::get_target_framerate(uint32_t original) {
     ultramodern::GraphicsConfig graphics_config = ultramodern::get_graphics_config();
@@ -298,6 +299,10 @@ uint32_t ultramodern::get_display_refresh_rate() {
     return display_refresh_rate.load();
 }
 
+float ultramodern::get_resolution_scale() {
+    return resolution_scale.load();
+}
+
 void ultramodern::load_shader_cache(std::span<const char> cache_data) {
     events_context.action_queue.enqueue(LoadShaderCacheAction{cache_data});
 }
@@ -359,6 +364,7 @@ void gfx_thread_func(uint8_t* rdram, moodycamel::LightweightSemaphore* thread_re
                 events_context.vi.current_buffer = events_context.vi.next_buffer;
                 rt64.update_screen(swap_action->origin);
                 display_refresh_rate = rt64.get_display_framerate();
+                resolution_scale = rt64.get_resolution_scale();
             }
             else if (const auto* config_action = std::get_if<UpdateConfigAction>(&action)) {
                 ultramodern::GraphicsConfig new_config = cur_config;

ultramodern/rt64_layer.cpp

@@ -278,6 +278,24 @@ uint32_t ultramodern::RT64Context::get_display_framerate() {
     return app->presentQueue->ext.sharedResources->swapChainRate;
 }
 
+float ultramodern::RT64Context::get_resolution_scale() {
+    constexpr int ReferenceHeight = 240;
+    switch (app->userConfig.resolution) {
+        case RT64::UserConfiguration::Resolution::WindowIntegerScale:
+            if (app->sharedQueueResources->swapChainHeight > 0) {
+                return std::max(float((app->sharedQueueResources->swapChainHeight + ReferenceHeight - 1) / ReferenceHeight), 1.0f);
+            }
+            else {
+                return 1.0f;
+            }
+        case RT64::UserConfiguration::Resolution::Manual:
+            return float(app->userConfig.resolutionMultiplier);
+        case RT64::UserConfiguration::Resolution::Original:
+        default:
+            return 1.0f;
+    }
+}
+
 void ultramodern::RT64Context::load_shader_cache(std::span<const char> cache_binary) {
     // TODO figure out how to avoid a copy here.
     std::istringstream cache_stream{std::string{cache_binary.data(), cache_binary.size()}};

ultramodern/ultramodern.hpp

@@ -111,9 +111,9 @@ void sleep_milliseconds(uint32_t millis);
 void sleep_until(const std::chrono::high_resolution_clock::time_point& time_point);
 
 // Graphics
-void get_window_size(uint32_t& width, uint32_t& height);
 uint32_t get_target_framerate(uint32_t original);
 uint32_t get_display_refresh_rate();
+float get_resolution_scale();
 void load_shader_cache(std::span<const char> cache_data);
 
 // Audio