Added most recent version of unmodified HL2 SDK for Episode 1 engine

materialsystem/stdshaders/SDK_WaterCheap_ps11.psh

@@ -0,0 +1,45 @@
+ps.1.1
+
+; Get the 3-vector from the normal map
+tex t0
+
+; Perform matrix multiply to get a local normal bump.  Then
+; reflect the eye vector through the normal and sample from 
+; a cubic environment map.
+texm3x3pad t1, t0_bx2
+texm3x3pad t2, t0_bx2		
+texm3x3vspec t3, t0_bx2
+
+mul r0.rgb, t3, c1					; envmap color * envmaptint
+#ifndef _XBOX
++mov_sat r0.a, v0.a					; Put the cheap water blend factor here
+#else
++mov r0.a, v0_sat.a
+#endif
+
+#ifndef _XBOX
+dp3_sat t2, v0_bx2, t0_bx2			; dot eye-vector with per-pixel normal from t0
+#else
+dp3 t2, v0_bx2, t0_bx2
+mov t2, t2_sat
+#endif
+
+; run Fresnel approx. on it: R0 + (1-R0) (1-cos(q))^5 in alpha channel
+; NOTE: This is not perspective-correct and results in strange artifacts
+mul r1.a, 1-t2.a, 1-t2.a			; squared
+mul r1.a, r1.a, r1.a				; quartic
+#ifndef _XBOX
+mul_sat r1.a, r1.a, 1-t2.a			; quintic
+#else
+mul r1.a, r1.a, 1-t2.a
+mov r1.a, r1_sat.a
+#endif
+
+; t1.a is now the fresnel factor
+#ifndef _XBOX
+add_sat r0.a, r1.a, r0.a			; Now we have the final blend factor between cheap water + refraction
+#else
+; out of instructions, saturate possibly not needed
+add r0.a, r1.a, r0.a
+#endif
+