1 files changed, 41 insertions, 0 deletions
diff --git a/src/shader/FoamGeneration_glsl_ps.h b/src/shader/FoamGeneration_glsl_ps.h
new file mode 100644
index 0000000..0ab5eed
--- /dev/null
+++ b/src/shader/FoamGeneration_glsl_ps.h
@@ -0,0 +1,41 @@
+R"glsl(
+//------------------------------------------------------------------------------------
+// Global variables
+//------------------------------------------------------------------------------------
+
+uniform vec4 g_DissipationFactors;
+uniform vec4 g_SourceComponents;
+uniform vec4 g_UVOffsets;
+
+uniform sampler2D g_samplerDisplacementMap;
+
+varying float2 vInterpTexCoord;
+
+// at 1st rendering step, the folding and the accumulated foam values are being read from gradient map (components z and w),
+// blurred by X, summed, faded and written to foam energy map 
+
+// at 2nd rendering step, the accumulated foam values are being read from foam energy texture,
+// blurred by Y and written to w component of gradient map
+
+void main()
+{
+
+	float2 UVoffset = g_UVOffsets.xy*g_DissipationFactors.x;
+
+	// blur with variable size kernel is done by doing 4 bilinear samples, 
+	// each sample is slightly offset from the center point
+	float foamenergy1	= dot(g_SourceComponents, texture(g_samplerEnergyMap, vInterpTexCoord.xy + UVoffset));
+	float foamenergy2	= dot(g_SourceComponents, texture(g_samplerEnergyMap, vInterpTexCoord.xy - UVoffset));
+	float foamenergy3	= dot(g_SourceComponents, texture(g_samplerEnergyMap, vInterpTexCoord.xy + UVoffset*2.0));
+	float foamenergy4	= dot(g_SourceComponents, texture(g_samplerEnergyMap, vInterpTexCoord.xy - UVoffset*2.0));
+	
+	float folding = max(0,texture(g_samplerEnergyMap, vInterpTexCoord.xy).z);
+
+	float energy = g_DissipationFactors.y*((foamenergy1 + foamenergy2 + foamenergy3 + foamenergy4)*0.25 + max(0,(1.0-folding-g_DissipationFactors.w))*g_DissipationFactors.z);
+
+	energy = min(1.0,energy);
+
+	// Output
+	gl_FragColor = float4(energy,energy,energy,energy);
+}
+)glsl";