Fatal: Implement basic background drawing.

stratosphere/fatal/source/fatal_main.cpp

@@ -39,8 +39,8 @@ extern "C" {
     char   nx_inner_heap[INNER_HEAP_SIZE];
     
     u32 __nx_nv_transfermem_size = 0x40000;
-    ViServiceType __nx_gfx_vi_service_type = ViServiceType_Manager;
-
+    ViLayerFlags __nx_vi_stray_layer_flags = (ViLayerFlags)0;
+    
     void __libnx_initheap(void);
     void __appInit(void);
     void __appExit(void);

stratosphere/fatal/source/fatal_task_screen.cpp

@@ -18,11 +18,158 @@
 #include "fatal_task_screen.hpp"
 #include "fatal_config.hpp"
 
+Result ShowFatalTask::SetupDisplayInternal() {
+    Result rc;
+    ViDisplay display;
+    /* Try to open the display. */
+    if (R_FAILED((rc = viOpenDisplay("Internal", &display)))) {
+        if (rc == 0xE72) {
+            return 0;
+        } else {
+            return rc;
+        }
+    }
+    /* Guarantee we close the display. */
+    ON_SCOPE_EXIT { viCloseDisplay(&display); };
+    
+    /* Turn on the screen. */
+    if (R_FAILED((rc = viSetDisplayPowerState(&display, ViPowerState_On)))) {
+        return rc;
+    }
+    
+    /* Set alpha to 1.0f. */
+    if (R_FAILED((rc = viSetDisplayAlpha(&display, 1.0f)))) {
+        return rc;
+    }
+    
+    return rc;
+}
+
+Result ShowFatalTask::SetupDisplayExternal() {
+    Result rc;
+    ViDisplay display;
+    /* Try to open the display. */
+    if (R_FAILED((rc = viOpenDisplay("External", &display)))) {
+        if (rc == 0xE72) {
+            return 0;
+        } else {
+            return rc;
+        }
+    }
+    /* Guarantee we close the display. */
+    ON_SCOPE_EXIT { viCloseDisplay(&display); };
+    
+    /* Set alpha to 1.0f. */
+    if (R_FAILED((rc = viSetDisplayAlpha(&display, 1.0f)))) {
+        return rc;
+    }
+    
+    return rc;
+}
+
+Result ShowFatalTask::PrepareScreenForDrawing() {
+    Result rc = 0;
+    
+    /* Connect to vi. */
+    if (R_FAILED((rc = viInitialize(ViServiceType_Manager)))) {
+        return rc;
+    }
+    
+    /* Close other content. */
+    viSetContentVisibility(false);
+    
+    /* Setup the two displays. */
+    if (R_FAILED((rc = SetupDisplayInternal())) || R_FAILED((rc = SetupDisplayExternal()))) {
+        return rc;
+    }
+    
+    /* Open the default display. */
+    if (R_FAILED((rc = viOpenDefaultDisplay(&this->display)))) {
+        return rc;
+    }
+    
+    /* Reset the display magnification to its default value. */
+    u32 display_width, display_height;
+    if (R_FAILED((rc = viGetDisplayLogicalResolution(&this->display, &display_width, &display_height)))) {
+        return rc;
+    }
+    if (R_FAILED((rc = viSetDisplayMagnification(&this->display, 0, 0, display_width, display_height)))) {
+        return rc;
+    }
+    
+    /* Create layer to draw to. */
+    if (R_FAILED((rc = viCreateLayer(&this->display, &this->layer)))) {
+        return rc;
+    }
+    
+    /* Setup the layer. */
+    {
+        /* Display a layer of 1280 x 720 at 1.5x magnification */
+        /* NOTE: N uses 2 (770x400) RGBA4444 buffers (tiled buffer + linear). */
+        /* We use a single 1280x720 tiled RGB565 buffer. */
+        constexpr u32 raw_width = 1280;
+        constexpr u32 raw_height = 720;
+        constexpr u32 layer_width = ((raw_width) * 3) / 2;
+        constexpr u32 layer_height = ((raw_height) * 3) / 2;
+        
+        const float layer_x = static_cast<float>((display_width - layer_width) / 2);
+        const float layer_y = static_cast<float>((display_height - layer_height) / 2);
+        u64 layer_z;
+        
+        if (R_FAILED((rc = viSetLayerSize(&this->layer, layer_width, layer_height)))) {
+            return rc;
+        }
+        
+        /* Set the layer's Z at display maximum, to be above everything else .*/
+        /* NOTE: Fatal hardcodes 100 here. */
+        if (R_SUCCEEDED((rc = viGetDisplayMaximumZ(&this->display, &layer_z)))) {
+            if (R_FAILED((rc = viSetLayerZ(&this->layer, layer_z)))) {
+                return rc;
+            }
+        }
+        
+        /* Center the layer in the screen. */
+        if (R_FAILED((rc = viSetLayerPosition(&this->layer, layer_x, layer_y)))) {
+            return rc;
+        }
+    
+        /* Create framebuffer. */
+        if (R_FAILED(rc = nwindowCreateFromLayer(&this->win, &this->layer))) {
+            return rc;
+        }
+        if (R_FAILED(rc = framebufferCreate(&this->fb, &this->win, raw_width, raw_height, PIXEL_FORMAT_RGB_565, 1))) {
+            return rc;
+        }
+    }
+    
+
+    return rc;
+}
+
 Result ShowFatalTask::ShowFatal() {
     Result rc = 0;
 
-    /* TODO: Get graphics to work, draw fatal screen. */
-
+    if (R_FAILED((rc = PrepareScreenForDrawing()))) {
+        *(volatile u32 *)(0xCAFEBABE) = rc;
+        return rc;
+    }
+    
+    /* Dequeue a buffer. */
+    u16 *tiled_buf = reinterpret_cast<u16 *>(framebufferBegin(&this->fb, NULL));
+    if (tiled_buf == nullptr) {
+        return FatalResult_NullGfxBuffer;
+    }
+    
+    /* Draw a background. */
+    for (size_t i = 0; i < this->fb.fb_size / sizeof(*tiled_buf); i++) {
+        tiled_buf[i] = 0x39C9;
+    }
+    
+    /* TODO: Actually draw meaningful shit here. */
+    
+    /* Enqueue the buffer. */
+    framebufferEnd(&fb);
+    
     return rc;
 }
 

stratosphere/fatal/source/fatal_task_screen.hpp

@@ -22,7 +22,14 @@
 class ShowFatalTask : public IFatalTask {
     private:
         Event *battery_event;
+        ViDisplay display;
+        ViLayer layer;
+        NWindow win;
+        Framebuffer fb;
     private:
+        Result SetupDisplayInternal();
+        Result SetupDisplayExternal();
+        Result PrepareScreenForDrawing();
         Result ShowFatal();
     public:
         ShowFatalTask(FatalContext *ctx, u64 title_id, Event *evt) : IFatalTask(ctx, title_id), battery_event(evt) { }

stratosphere/fatal/source/fatal_types.hpp

@@ -19,6 +19,7 @@
 #include <stratosphere.hpp>
 
 enum FatalResult : Result {
+    FatalResult_NullGfxBuffer = 0x4A3,
     FatalResult_AlreadyThrown = 0x6A3,
     FatalResult_TooManyEvents = 0x8A3,
     FatalResult_InRepairWithoutVolHeld = 0xAA3,