Handle dual cycle noise.

Themaister · May 25, 2024 · c84dc7f · c84dc7f
1 parent 66b9bf3
commit c84dc7f
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Showing 4 changed files with 19 additions and 3 deletions.
diff --git a/parallel-rdp/rdp_data_structures.hpp b/parallel-rdp/rdp_data_structures.hpp
@@ -70,7 +70,9 @@ enum StaticRasterizationFlagBits
 	RASTERIZATION_CONVERT_ONE_BIT = 1 << 22,
 	RASTERIZATION_BILERP_0_BIT = 1 << 23,
 	RASTERIZATION_BILERP_1_BIT = 1 << 24,
+	RASTERIZATION_NEED_NOISE_DUAL_BIT = 1 << 25,
 	RASTERIZATION_UPSCALING_LOG2_BIT_OFFSET = 26,
+	// Bit 26 and 27 holds upscaling factor in LOG2.
 	RASTERIZATION_NEED_NOISE_BIT = 1 << 28,
 	RASTERIZATION_USE_STATIC_TEXTURE_SIZE_FORMAT_BIT = 1 << 29,
 	RASTERIZATION_USE_SPECIALIZATION_CONSTANT_BIT = 1 << 30

diff --git a/parallel-rdp/rdp_renderer.cpp b/parallel-rdp/rdp_renderer.cpp
@@ -1131,7 +1131,7 @@ static bool combiner_uses_lod_frac(const StaticRasterizationState &state)
 void Renderer::deduce_noise_state()
 {
 	auto &state = stream.static_raster_state;
-	state.flags &= ~RASTERIZATION_NEED_NOISE_BIT;
+	state.flags &= ~(RASTERIZATION_NEED_NOISE_BIT | RASTERIZATION_NEED_NOISE_DUAL_BIT);
 
 	// Figure out if we need to seed noise variable for this primitive.
 	if ((state.dither & 3) == 2 || ((state.dither >> 2) & 3) == 2)
@@ -1144,13 +1144,18 @@ void Renderer::deduce_noise_state()
 		return;
 
 	if ((state.flags & RASTERIZATION_MULTI_CYCLE_BIT) != 0)
-	{
 		if (state.combiner[0].rgb.muladd == RGBMulAdd::Noise)
 			state.flags |= RASTERIZATION_NEED_NOISE_BIT;
-	}
+
 	if (state.combiner[1].rgb.muladd == RGBMulAdd::Noise)
 		state.flags |= RASTERIZATION_NEED_NOISE_BIT;
 
+	// If both cycles use noise, they need to observe different values.
+	if ((state.flags & RASTERIZATION_MULTI_CYCLE_BIT) != 0 &&
+	    state.combiner[0].rgb.muladd == RGBMulAdd::Noise &&
+	    state.combiner[1].rgb.muladd == RGBMulAdd::Noise)
+		state.flags |= RASTERIZATION_NEED_NOISE_DUAL_BIT;
+
 	if ((state.flags & (RASTERIZATION_ALPHA_TEST_BIT | RASTERIZATION_ALPHA_TEST_DITHER_BIT)) ==
 	    (RASTERIZATION_ALPHA_TEST_BIT | RASTERIZATION_ALPHA_TEST_DITHER_BIT))
 	{

diff --git a/parallel-rdp/shaders/data_structures.h b/parallel-rdp/shaders/data_structures.h
@@ -61,6 +61,7 @@ const int RASTERIZATION_USES_PIPELINED_TEXEL1_BIT = 1 << 21;
 const int RASTERIZATION_CONVERT_ONE_BIT = 1 << 22;
 const int RASTERIZATION_BILERP_0_BIT = 1 << 23;
 const int RASTERIZATION_BILERP_1_BIT = 1 << 24;
+const int RASTERIZATION_NEED_NOISE_DUAL_BIT = 1 << 25;
 const int RASTERIZATION_UPSCALING_LOG2_BIT_OFFSET = 26;
 const int RASTERIZATION_NEED_NOISE_BIT = 1 << 28;
 const int RASTERIZATION_USE_STATIC_TEXTURE_SIZE_FORMAT_BIT = 1 << 29;

diff --git a/parallel-rdp/shaders/shading.h b/parallel-rdp/shaders/shading.h
@@ -306,6 +306,14 @@ bool shade_pixel(int x, int y, uint primitive_index, out ShadedData shaded)
 		// but let's not go there ...
 		combined_inputs.texel1 = tmp_texel;
 
+		// Resample the noise at some arbitrary other offset.
+		// This only matters if both noise combiner inputs take noise (very weird).
+		if ((static_state_flags & RASTERIZATION_NEED_NOISE_DUAL_BIT) != 0)
+		{
+			reseed_noise(x + 1023, y + 7, primitive_index + global_constants.fb_info.base_primitive_index + 11);
+			combined_inputs.noise = noise_get_combiner();
+		}
+
 		combined = u8x4(combiner_cycle1(combined_inputs,
 		                                combiner_inputs_rgb1,
 		                                combiner_inputs_alpha1,