new cvar r_glsl_contrastboost to do something similar to gamma in the GLSL shader...

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@7377 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/gl_rmain.c b/gl_rmain.c
index a0bd28084ee083a6a055465552b310ca89e383dd..8243ef922522c66c10c6af88509f6542718c9b1a 100644 (file)
--- a/gl_rmain.c
+++ b/gl_rmain.c
@@ -79,6 +79,7 @@ cvar_t r_glsl_offsetmapping = {CVAR_SAVE, "r_glsl_offsetmapping", "0", "offset m
 cvar_t r_glsl_offsetmapping_reliefmapping = {CVAR_SAVE, "r_glsl_offsetmapping_reliefmapping", "0", "relief mapping effect (higher quality)"};
 cvar_t r_glsl_offsetmapping_scale = {CVAR_SAVE, "r_glsl_offsetmapping_scale", "0.04", "how deep the offset mapping effect is"};
 cvar_t r_glsl_deluxemapping = {CVAR_SAVE, "r_glsl_deluxemapping", "1", "use per pixel lighting on deluxemap-compiled q3bsp maps (or a value of 2 forces deluxemap shading even without deluxemaps)"};
+cvar_t r_glsl_contrastboost = {CVAR_SAVE, "r_glsl_contrastboost", "1", "by how much to multiply the contrast in dark areas (1 is no change)"};
 
 cvar_t r_lerpsprites = {CVAR_SAVE, "r_lerpsprites", "1", "enables animation smoothing on sprites (requires r_lerpmodels 1)"};
 cvar_t r_lerpmodels = {CVAR_SAVE, "r_lerpmodels", "1", "enables animation smoothing on models"};
@@ -487,6 +488,9 @@ static const char *builtinshaderstring =
 "\n"
 "uniform myhalf GlowScale;\n"
 "uniform myhalf SceneBrightness;\n"
+"#ifdef USECONTRASTBOOST\n"
+"uniform myhalf ContrastBoostCoeff;\n"
+"#endif\n"
 "\n"
 "uniform float OffsetMapping_Scale;\n"
 "uniform float OffsetMapping_Bias;\n"
@@ -651,7 +655,11 @@ static const char *builtinshaderstring =
 "      color.rgb = mix(FogColor, color.rgb, myhalf(texture2D(Texture_FogMask, myhvec2(length(EyeVectorModelSpace)*FogRangeRecip, 0.0))));\n"
 "#endif\n"
 "\n"
+"#ifdef USECONTRASTBOOST\n"
+"      color.rgb = SceneBrightness / (ContrastBoostCoeff + 1 / color.rgb);\n"
+"#else\n"
 "      color.rgb *= SceneBrightness;\n"
+"#endif\n"
 "\n"
 "      gl_FragColor = vec4(color);\n"
 "}\n"
@@ -670,6 +678,7 @@ const char *permutationinfo[][2] =
        {"#define USEFOG\n", " fog"},
        {"#define USECOLORMAPPING\n", " colormapping"},
        {"#define USEDIFFUSE\n", " diffuse"},
+       {"#define USECONTRASTBOOST\n", " contrastboost"},
        {"#define USESPECULAR\n", " specular"},
        {"#define USECUBEFILTER\n", " cubefilter"},
        {"#define USEOFFSETMAPPING\n", " offsetmapping"},
@@ -781,6 +790,7 @@ void R_GLSL_CompilePermutation(const char *filename, int permutation)
                p->loc_DiffuseColor        = qglGetUniformLocationARB(p->program, "DiffuseColor");
                p->loc_SpecularColor       = qglGetUniformLocationARB(p->program, "SpecularColor");
                p->loc_LightDir            = qglGetUniformLocationARB(p->program, "LightDir");
+               p->loc_ContrastBoostCoeff  = qglGetUniformLocationARB(p->program, "ContrastBoostCoeff");
                // initialize the samplers to refer to the texture units we use
                if (p->loc_Texture_Normal >= 0)    qglUniform1iARB(p->loc_Texture_Normal, 0);
                if (p->loc_Texture_Color >= 0)     qglUniform1iARB(p->loc_Texture_Color, 1);
@@ -845,6 +855,8 @@ int R_SetupSurfaceShader(const vec3_t lightcolorbase, qboolean modellighting, fl
                        if (r_glsl_offsetmapping_reliefmapping.integer)
                                permutation |= SHADERPERMUTATION_OFFSETMAPPING_RELIEFMAPPING;
                }
+               if(r_glsl_contrastboost.value != 1 && r_glsl_contrastboost.value != 0)
+                       permutation |= SHADERPERMUTATION_CONTRASTBOOST;
        }
        else if (rsurface.texture->currentmaterialflags & MATERIALFLAG_FULLBRIGHT)
        {
@@ -863,6 +875,8 @@ int R_SetupSurfaceShader(const vec3_t lightcolorbase, qboolean modellighting, fl
                        if (r_glsl_offsetmapping_reliefmapping.integer)
                                permutation |= SHADERPERMUTATION_OFFSETMAPPING_RELIEFMAPPING;
                }
+               if(r_glsl_contrastboost.value != 1 && r_glsl_contrastboost.value != 0)
+                       permutation |= SHADERPERMUTATION_CONTRASTBOOST;
        }
        else if (modellighting)
        {
@@ -884,6 +898,8 @@ int R_SetupSurfaceShader(const vec3_t lightcolorbase, qboolean modellighting, fl
                        if (r_glsl_offsetmapping_reliefmapping.integer)
                                permutation |= SHADERPERMUTATION_OFFSETMAPPING_RELIEFMAPPING;
                }
+               if(r_glsl_contrastboost.value != 1 && r_glsl_contrastboost.value != 0)
+                       permutation |= SHADERPERMUTATION_CONTRASTBOOST;
        }
        else
        {
@@ -924,6 +940,8 @@ int R_SetupSurfaceShader(const vec3_t lightcolorbase, qboolean modellighting, fl
                        if (r_glsl_offsetmapping_reliefmapping.integer)
                                permutation |= SHADERPERMUTATION_OFFSETMAPPING_RELIEFMAPPING;
                }
+               if(r_glsl_contrastboost.value != 1 && r_glsl_contrastboost.value != 0)
+                       permutation |= SHADERPERMUTATION_CONTRASTBOOST;
        }
        if (!r_glsl_permutations[permutation & SHADERPERMUTATION_MASK].program)
        {
@@ -1001,7 +1019,22 @@ int R_SetupSurfaceShader(const vec3_t lightcolorbase, qboolean modellighting, fl
        //if (r_glsl_permutation->loc_Texture_Deluxemap >= 0) R_Mesh_TexBind(8, R_GetTexture(r_texture_blanknormalmap));
        if (r_glsl_permutation->loc_Texture_Glow >= 0) R_Mesh_TexBind(9, R_GetTexture(rsurface.texture->currentskinframe->glow));
        if (r_glsl_permutation->loc_GlowScale >= 0) qglUniform1fARB(r_glsl_permutation->loc_GlowScale, r_hdr_glowintensity.value);
-       if (r_glsl_permutation->loc_SceneBrightness >= 0) qglUniform1fARB(r_glsl_permutation->loc_SceneBrightness, r_view.colorscale);
+       if (r_glsl_permutation->loc_ContrastBoostCoeff >= 0)
+       {
+               // The formula used is actually:
+               //   color.rgb *= SceneBrightness;
+               //   color.rgb *= ContrastBoost / ((ContrastBoost - 1) * color.rgb + 1);
+               // I simplify that to
+               //   color.rgb *= [[SceneBrightness * ContrastBoost]];
+               //   color.rgb /= [[(ContrastBoost - 1) / ContrastBoost]] * color.rgb + 1;
+               // and Black:
+               //   color.rgb = [[SceneBrightness * ContrastBoost]] / ([[(ContrastBoost - 1) * SceneBrightness]] + 1 / color.rgb);
+               // and do [[calculations]] here in the engine
+               qglUniform1fARB(r_glsl_permutation->loc_ContrastBoostCoeff, (r_glsl_contrastboost.value - 1) * r_view.colorscale);
+               if (r_glsl_permutation->loc_SceneBrightness >= 0) qglUniform1fARB(r_glsl_permutation->loc_SceneBrightness, r_view.colorscale * r_glsl_contrastboost.value);
+       }
+       else
+               if (r_glsl_permutation->loc_SceneBrightness >= 0) qglUniform1fARB(r_glsl_permutation->loc_SceneBrightness, r_view.colorscale);
        if (r_glsl_permutation->loc_FogColor >= 0)
        {
                // additive passes are only darkened by fog, not tinted
@@ -1515,6 +1548,7 @@ void GL_Main_Init(void)
        Cvar_RegisterVariable(&r_bloom_colorsubtract);
        Cvar_RegisterVariable(&r_hdr);
        Cvar_RegisterVariable(&r_hdr_scenebrightness);
+       Cvar_RegisterVariable(&r_glsl_contrastboost);
        Cvar_RegisterVariable(&r_hdr_glowintensity);
        Cvar_RegisterVariable(&r_hdr_range);
        Cvar_RegisterVariable(&r_smoothnormals_areaweighting);

diff --git a/render.h b/render.h
index 72d93f37acf4f0fe3be27be8c67c632e499f8e5c..b933881d65f9176d73cb27bd7d089ce3c24b11bf 100644 (file)
--- a/render.h
+++ b/render.h
@@ -366,12 +366,13 @@ void RSurf_DrawBatch_Simple(int texturenumsurfaces, msurface_t **texturesurfacel
 #define SHADERPERMUTATION_FOG (1<<5) // tint the color by fog color or black if using additive blend mode
 #define SHADERPERMUTATION_COLORMAPPING (1<<6) // indicates this is a colormapped skin
 #define SHADERPERMUTATION_DIFFUSE (1<<7) // (lightsource) whether to use directional shading
-#define SHADERPERMUTATION_SPECULAR (1<<8) // (lightsource or deluxemapping) render specular effects
-#define SHADERPERMUTATION_CUBEFILTER (1<<9) // (lightsource) use cubemap light filter
-#define SHADERPERMUTATION_OFFSETMAPPING (1<<10) // adjust texcoords to roughly simulate a displacement mapped surface
-#define SHADERPERMUTATION_OFFSETMAPPING_RELIEFMAPPING (1<<11) // adjust texcoords to accurately simulate a displacement mapped surface (requires OFFSETMAPPING to also be set!)
+#define SHADERPERMUTATION_CONTRASTBOOST (1<<8) // r_glsl_contrastboost boosts the contrast at low color levels (similar to gamma)
+#define SHADERPERMUTATION_SPECULAR (1<<9) // (lightsource or deluxemapping) render specular effects
+#define SHADERPERMUTATION_CUBEFILTER (1<<10) // (lightsource) use cubemap light filter
+#define SHADERPERMUTATION_OFFSETMAPPING (1<<11) // adjust texcoords to roughly simulate a displacement mapped surface
+#define SHADERPERMUTATION_OFFSETMAPPING_RELIEFMAPPING (1<<12) // adjust texcoords to accurately simulate a displacement mapped surface (requires OFFSETMAPPING to also be set!)
 
-#define SHADERPERMUTATION_MAX (1<<12) // how many permutations are possible
+#define SHADERPERMUTATION_MAX (1<<13) // how many permutations are possible
 #define SHADERPERMUTATION_MASK (SHADERPERMUTATION_MAX - 1) // mask of valid indexing bits for r_glsl_permutations[] array
 
 // these are additional flags used only by R_GLSL_CompilePermutation
@@ -408,12 +409,13 @@ typedef struct r_glsl_permutation_s
        int loc_SpecularScale;
        int loc_SpecularPower;
        int loc_GlowScale;
-       int loc_SceneBrightness;
+       int loc_SceneBrightness; // or: Scenebrightness * ContrastBoost
        int loc_OffsetMapping_Scale;
        int loc_AmbientColor;
        int loc_DiffuseColor;
        int loc_SpecularColor;
        int loc_LightDir;
+       int loc_ContrastBoostCoeff; // 1 - 1/ContrastBoost
 }
 r_glsl_permutation_t;