significant cleanup of reliefmapping shader, now uses step() function

instead of if's, this might improve compatibility with ATI cards, but
not sure, in any case I improved the stepping math a little bit which
saves some time, minor fps improvement on reliefmapping compared to
before

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@7142 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/gl_rmain.c b/gl_rmain.c
index bfef3c49d083b245f3b1575302c096de1d9e0e08..dd059df3793141274f266d49bc7e2830dfc8495f 100644 (file)
--- a/gl_rmain.c
+++ b/gl_rmain.c
@@ -147,9 +147,6 @@ r_glsl_permutation_t r_glsl_permutations[SHADERPERMUTATION_MAX];
 // currently selected permutation
 r_glsl_permutation_t *r_glsl_permutation;
 
-// temporary variable used by a macro
-int fogtableindex;
-
 // vertex coordinates for a quad that covers the screen exactly
 const static float r_screenvertex3f[12] =
 {
@@ -511,50 +508,55 @@ static const char *builtinshaderstring =
 "uniform myhalf SpecularScale;\n"
 "uniform myhalf SpecularPower;\n"
 "\n"
+"#ifdef USEOFFSETMAPPING\n"
 "vec2 OffsetMapping(vec2 TexCoord)\n"
 "{\n"
-"      vec3 eyedir = vec3(normalize(EyeVector));\n"
-"      float depthbias = 1.0 - eyedir.z; // should this be a -?\n"
-"      depthbias = 1.0 - depthbias * depthbias;\n"
-"\n"
 "#ifdef USEOFFSETMAPPING_RELIEFMAPPING\n"
 "      // 14 sample relief mapping: linear search and then binary search\n"
-"      //vec3 OffsetVector = vec3(EyeVector.xy * (1.0 / EyeVector.z) * depthbias * OffsetMapping_Scale * vec2(-0.1, 0.1), -0.1);\n"
-"      //vec3 OffsetVector = vec3(normalize(EyeVector.xy) * OffsetMapping_Scale * vec2(-0.1, 0.1), -0.1);\n"
-"      vec3 OffsetVector = vec3(eyedir.xy * OffsetMapping_Scale * vec2(-0.1, 0.1), -0.1);\n"
-"      vec3 RT = vec3(TexCoord - OffsetVector.xy * 10.0, 1.0) + OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;OffsetVector *= 0.5;RT -= OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;OffsetVector *= 0.5;RT -= OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;OffsetVector *= 0.5;RT -= OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;OffsetVector *= 0.5;RT -= OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;OffsetVector *= 0.5;RT -= OffsetVector;\n"
-"      if (RT.z > texture2D(Texture_Normal, RT.xy).a) RT += OffsetVector;OffsetVector *= 0.5;RT -= OffsetVector;\n"
-"      TexCoord = RT.xy;\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"
+"      //vec3 OffsetVector = vec3(EyeVector.xy * ((1.0 / EyeVector.z) * OffsetMapping_Scale) * vec2(-1, 1), -1);\n"
+"      //vec3 OffsetVector = vec3(normalize(EyeVector.xy) * OffsetMapping_Scale * vec2(-1, 1), -1);\n"
+"      vec3 OffsetVector = vec3(normalize(EyeVector).xy * OffsetMapping_Scale * vec2(-1, 1), -1);\n"
+"      vec3 RT = vec3(TexCoord, 1);\n"
+"      OffsetVector *= 0.1;\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector *  step(texture2D(Texture_Normal, RT.xy).a, RT.z);\n"
+"      RT += OffsetVector * (step(texture2D(Texture_Normal, RT.xy).a, RT.z)          - 0.5);\n"
+"      RT += OffsetVector * (step(texture2D(Texture_Normal, RT.xy).a, RT.z) * 0.5    - 0.25);\n"
+"      RT += OffsetVector * (step(texture2D(Texture_Normal, RT.xy).a, RT.z) * 0.25   - 0.125);\n"
+"      RT += OffsetVector * (step(texture2D(Texture_Normal, RT.xy).a, RT.z) * 0.125  - 0.0625);\n"
+"      RT += OffsetVector * (step(texture2D(Texture_Normal, RT.xy).a, RT.z) * 0.0625 - 0.03125);\n"
+"      return RT.xy;\n"
 "#else\n"
 "      // 3 sample offset mapping (only 3 samples because of ATI Radeon 9500-9800/X300 limits)\n"
-"      //vec2 OffsetVector = vec2(EyeVector.xy * (1.0 / EyeVector.z) * depthbias) * OffsetMapping_Scale * vec2(-0.333, 0.333);\n"
-"      //vec2 OffsetVector = vec2(normalize(EyeVector.xy)) * OffsetMapping_Scale * vec2(-0.333, 0.333);\n"
-"      vec2 OffsetVector = vec2(eyedir.xy) * OffsetMapping_Scale * vec2(-0.333, 0.333);\n"
-"      //TexCoord += OffsetVector * 3.0;\n"
+"      // this basically moves forward the full distance, and then backs up based\n"
+"      // on height of samples\n"
+"      //vec2 OffsetVector = vec2(EyeVector.xy * ((1.0 / EyeVector.z) * OffsetMapping_Scale) * vec2(-1, 1));\n"
+"      //vec2 OffsetVector = vec2(normalize(EyeVector.xy) * OffsetMapping_Scale * vec2(-1, 1));\n"
+"      vec2 OffsetVector = vec2(normalize(EyeVector).xy * OffsetMapping_Scale * vec2(-1, 1));\n"
+"      TexCoord += OffsetVector;\n"
+"      OffsetVector *= 0.333;\n"
 "      TexCoord -= OffsetVector * texture2D(Texture_Normal, TexCoord).a;\n"
 "      TexCoord -= OffsetVector * texture2D(Texture_Normal, TexCoord).a;\n"
 "      TexCoord -= OffsetVector * texture2D(Texture_Normal, TexCoord).a;\n"
-"#endif\n"
 "      return TexCoord;\n"
+"#endif\n"
 "}\n"
+"#endif\n"
 "\n"
 "void main(void)\n"
 "{\n"
-"      // apply offsetmapping\n"
 "#ifdef USEOFFSETMAPPING\n"
+"      // apply offsetmapping\n"
 "      vec2 TexCoordOffset = OffsetMapping(TexCoord);\n"
 "#define TexCoord TexCoordOffset\n"
 "#endif\n"
@@ -588,7 +590,7 @@ static const char *builtinshaderstring =
 "      myhvec3 diffusenormal = myhvec3(normalize(LightVector));\n"
 "\n"
 "      // calculate directional shading\n"
-"      color.rgb = LightColor * myhalf(texture2D(Texture_Attenuation, vec2(length(CubeVector), 0.0))) * color.rgb * (AmbientScale + DiffuseScale * myhalf(max(float(dot(surfacenormal, diffusenormal)), 0.0)));\n"
+"      color.rgb = color.rgb * LightColor * (myhalf(texture2D(Texture_Attenuation, vec2(length(CubeVector), 0.0))) * (AmbientScale + DiffuseScale * myhalf(max(float(dot(surfacenormal, diffusenormal)), 0.0))));\n"
 "#else\n"
 "      // calculate directionless shading\n"
 "      color.rgb = color.rgb * LightColor * myhalf(texture2D(Texture_Attenuation, vec2(length(CubeVector), 0.0)));\n"
@@ -657,8 +659,7 @@ static const char *builtinshaderstring =
 "\n"
 "#ifdef USEFOG\n"
 "      // apply fog\n"
-"      myhalf fog = myhalf(texture2D(Texture_FogMask, myhvec2(length(EyeVectorModelSpace)*FogRangeRecip, 0.0)).x);\n"
-"      color.rgb = color.rgb * fog + FogColor * (1.0 - fog);\n"
+"      color.rgb = mix(FogColor, color.rgb, myhalf(texture2D(Texture_FogMask, myhvec2(length(EyeVectorModelSpace)*FogRangeRecip, 0.0))));\n"
 "#endif\n"
 "\n"
 "      color.rgb *= SceneBrightness;\n"