Experimental r_glsl_offsetmapping_lod cvar which applies a distance-based correction...

[xonotic/darkplaces.git] / shader_hlsl.h

diff --git a/shader_hlsl.h b/shader_hlsl.h
index 8c84666f08baa1c285a582f9bff07c724513c94f..1586d05e6412d12e791dc6baf9b0820d1b1bcca2 100644 (file)
--- a/shader_hlsl.h
+++ b/shader_hlsl.h
@@ -544,31 +544,38 @@
 "#endif\n"
 "\n"
 "#ifdef USEOFFSETMAPPING\n"
-"float2 OffsetMapping(float2 TexCoord, float4 OffsetMapping_ScaleSteps, float3 EyeVector, sampler Texture_Normal, float2 dPdx, float2 dPdy)\n"
+"float2 OffsetMapping(float2 TexCoord, float4 OffsetMapping_ScaleSteps, float OffsetMapping_LodDistance, float3 EyeVector, sampler Texture_Normal, float2 dPdx, float2 dPdy)\n"
 "{\n"
 "      float i;\n"
+"      // distance-based LOD\n"
+"#ifdef USEOFFSETMAPPING_LOD\n"
+"      float LODFactor = min(1.0, OffsetMapping_LodDistance / EyeVectorFogDepth.z);\n"
+"      mediump vec4 ScaleSteps = float4(OffsetMapping_ScaleSteps.x, OffsetMapping_ScaleSteps.y * LODFactor, OffsetMapping_ScaleSteps.z / LODFactor, OffsetMapping_ScaleSteps.w * LODFactor);\n"
+"#else\n"
+"      #define ScaleSteps OffsetMapping_ScaleSteps\n"
+"#endif\n"
 "#ifdef USEOFFSETMAPPING_RELIEFMAPPING\n"
 "      // 14 sample relief mapping: linear search and then binary search\n"
 "      // this basically steps forward a small amount repeatedly until it finds\n"
 "      // itself inside solid, then jitters forward and back using decreasing\n"
 "      // amounts to find the impact\n"
-"      //float3 OffsetVector = float3(EyeVector.xy * ((1.0 / EyeVector.z) * OffsetMapping_ScaleSteps.x) * float2(-1, 1), -1);\n"
-"      //float3 OffsetVector = float3(normalize(EyeVector.xy) * OffsetMapping_ScaleSteps.x * float2(-1, 1), -1);\n"
-"      float3 OffsetVector = float3(normalize(EyeVector).xy * OffsetMapping_ScaleSteps.x * float2(-1, 1), -1);\n"
+"      //float3 OffsetVector = float3(EyeVector.xy * ((1.0 / EyeVector.z) * ScaleSteps.x) * float2(-1, 1), -1);\n"
+"      //float3 OffsetVector = float3(normalize(EyeVector.xy) * ScaleSteps.x * float2(-1, 1), -1);\n"
+"      float3 OffsetVector = float3(normalize(EyeVector).xy * ScaleSteps.x * float2(-1, 1), -1);\n"
 "      float3 RT = float3(TexCoord, 1);\n"
-"      OffsetVector *= OffsetMapping_ScaleSteps.z;\n"
-"      for(i = 1.0; i < OffsetMapping_ScaleSteps.y; ++i)\n"
+"      OffsetVector *= ScaleSteps.z;\n"
+"      for(i = 1.0; i < ScaleSteps.y; ++i)\n"
 "              RT += OffsetVector *  step(tex2Dgrad(Texture_Normal, RT.xy, dPdx, dPdy).a, RT.z);\n"
-"      for(i = 0.0, f = 1.0; i < OffsetMapping_ScaleSteps.w; ++i, f *= 0.5)\n"
+"      for(i = 0.0, f = 1.0; i < ScaleSteps.w; ++i, f *= 0.5)\n"
 "              RT += OffsetVector * (step(tex2Dgrad(Texture_Normal, RT.xy, dPdx, dPdy).a, RT.z) * f - 0.5 * f);\n"
 "      return RT.xy;\n"
 "#else\n"
 "      // 2 sample offset mapping (only 2 samples because of ATI Radeon 9500-9800/X300 limits)\n"
-"      //float2 OffsetVector = float2(EyeVector.xy * ((1.0 / EyeVector.z) * OffsetMapping_ScaleSteps.x) * float2(-1, 1));\n"
-"      //float2 OffsetVector = float2(normalize(EyeVector.xy) * OffsetMapping_ScaleSteps.x * float2(-1, 1));\n"
-"      float2 OffsetVector = float2(normalize(EyeVector).xy * OffsetMapping_ScaleSteps.x * float2(-1, 1));\n"
-"      OffsetVector *= OffsetMapping_ScaleSteps.z;\n"
-"      for(i = 0.0; i < OffsetMapping_ScaleSteps.y; ++i)\n"
+"      //float2 OffsetVector = float2(EyeVector.xy * ((1.0 / EyeVector.z) * ScaleSteps.x) * float2(-1, 1));\n"
+"      //float2 OffsetVector = float2(normalize(EyeVector.xy) * ScaleSteps.x * float2(-1, 1));\n"
+"      float2 OffsetVector = float2(normalize(EyeVector).xy * ScaleSteps.x * float2(-1, 1));\n"
+"      OffsetVector *= ScaleSteps.z;\n"
+"      for(i = 0.0; i < ScaleSteps.y; ++i)\n"
 "              TexCoord += OffsetVector * (1.0 - tex2Dgrad(Texture_Normal, TexCoord, dPdx, dPdy).a);\n"
 "      return TexCoord;\n"
 "#endif\n"
@@ -786,6 +793,7 @@
 "#endif\n"
 "#ifdef USEOFFSETMAPPING\n"
 "uniform float4 OffsetMapping_ScaleSteps : register(c24),\n"
+"uniform float4 OffsetMapping_LodDistance : register(c53),\n"
 "#endif\n"
 "uniform half SpecularPower : register(c36),\n"
 "#ifdef HLSL\n"
@@ -801,7 +809,7 @@
 "      // apply offsetmapping\n"
 "      float2 dPdx = ddx(TexCoord);\n"
 "      float2 dPdy = ddy(TexCoord);\n"
-"      float2 TexCoordOffset = OffsetMapping(TexCoord, OffsetMapping_ScaleSteps, EyeVector, Texture_Normal, dPdx, dPdy);\n"
+"      float2 TexCoordOffset = OffsetMapping(TexCoord, OffsetMapping_ScaleSteps, OffsetMapping_LodDistance, EyeVector, Texture_Normal, dPdx, dPdy);\n"
 "# define offsetMappedTexture2D(t) tex2Dgrad(t, TexCoordOffset, dPdx, dPdy)\n"
 "#else\n"
 "# define offsetMappedTexture2D(t) tex2D(t, TexCoord)\n"
@@ -1285,7 +1293,7 @@
 "      // apply offsetmapping\n"
 "      float2 dPdx = ddx(TexCoord);\n"
 "      float2 dPdy = ddy(TexCoord);\n"
-"      float2 TexCoordOffset = OffsetMapping(TexCoord, OffsetMapping_ScaleSteps, EyeVector, Texture_Normal, dPdx, dPdy);\n"
+"      float2 TexCoordOffset = OffsetMapping(TexCoord, OffsetMapping_ScaleSteps, OffsetMapping_LodDistance, EyeVector, Texture_Normal, dPdx, dPdy);\n"
 "# define offsetMappedTexture2D(t) tex2Dgrad(t, TexCoordOffset, dPdx, dPdy)\n"
 "#else\n"
 "# define offsetMappedTexture2D(t) tex2D(t, TexCoord)\n"