vk: rt: add diffuse and specular debug display modes

These will display diffuse and specular channels, both direct and
indirect, after spatial denoiser, but before temporal one.

ref/vk/TODO.md

@@ -10,7 +10,8 @@
 	- [x] too dark indirect: blurSamples() returns values too small (incorrect sigma|scale?)
 		- [x] do a box blur test
 		- [x] do A-trous wavelet denoiser
-	- [ ] diffuse and specular debug display modes
+	- [ ] tune A-Trous step widths for different channels
+	- [x] diffuse and specular debug display modes
 	- [ ] temporal glitches with dontBlurSamples() and ATrous
 
 # Previously

ref/vk/shaders/denoiser.comp

@@ -401,6 +401,12 @@ void main() {
 	} else if (ubo.ubo.debug_display_only == DEBUG_DISPLAY_INDIRECT_DIFF) {
 		imageStore(out_dest, pix, vec4(LINEARtoSRGB(c.indirect_diffuse), 0.)); return;
 		return;
+	} else if (ubo.ubo.debug_display_only == DEBUG_DISPLAY_DIFFUSE) {
+		imageStore(out_dest, pix, vec4(LINEARtoSRGB(c.indirect_diffuse + c.direct_diffuse), 0.)); return;
+		return;
+	} else if (ubo.ubo.debug_display_only == DEBUG_DISPLAY_SPECULAR) {
+		imageStore(out_dest, pix, vec4(LINEARtoSRGB(c.indirect_specular + c.direct_specular), 0.)); return;
+		return;
 	}
 
 	vec3 diffuse = c.direct_diffuse + c.indirect_diffuse;

ref/vk/shaders/ray_interop.h

@@ -187,6 +187,8 @@ struct LightCluster {
 #define DEBUG_DISPLAY_INDIRECT_SPEC 13
 #define DEBUG_DISPLAY_TRIHASH 14
 #define DEBUG_DISPLAY_MATERIAL 15
+#define DEBUG_DISPLAY_DIFFUSE 16
+#define DEBUG_DISPLAY_SPECULAR 17
 // add more when needed
 
 #define DEBUG_FLAG_WHITE_FURNACE (1<<0)

ref/vk/vk_rtx.c

@@ -171,6 +171,8 @@ static void parseDebugDisplayValue( void ) {
 	X(INDIRECT_SPEC, "indirect specular only") \
 	X(TRIHASH, "each triangle is drawn with random color") \
 	X(MATERIAL, "red = roughness, green = metalness") \
+	X(DIFFUSE, "direct + indirect diffuse, spatially denoised") \
+	X(SPECULAR, "direct + indirect specular, spatially denoised") \
 
 #define X(suffix, info) \
 	if (0 == Q_stricmp(cvalue, #suffix)) { \