103 lines
3.5 KiB
GLSL
103 lines
3.5 KiB
GLSL
/**
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* @file class1/deferred/skyF.glsl
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*
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* $LicenseInfo:firstyear=2005&license=viewerlgpl$
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* Second Life Viewer Source Code
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* Copyright (C) 2005, Linden Research, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation;
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* version 2.1 of the License only.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
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* $/LicenseInfo$
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*/
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/*[EXTRA_CODE_HERE]*/
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// Inputs
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VARYING vec4 vary_HazeColor;
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VARYING float vary_LightNormPosDot;
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uniform sampler2D rainbow_map;
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uniform sampler2D halo_map;
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uniform float moisture_level;
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uniform float droplet_radius;
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uniform float ice_level;
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#ifdef DEFINE_GL_FRAGCOLOR
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out vec4 frag_data[3];
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#else
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#define frag_data gl_FragData
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#endif
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/////////////////////////////////////////////////////////////////////////
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// The fragment shader for the sky
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/////////////////////////////////////////////////////////////////////////
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vec3 rainbow(float d)
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{
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// 'Interesting' values of d are -0.75 .. -0.825, i.e. when view vec nearly opposite of sun vec
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// Rainbox tex is mapped with REPEAT, so -.75 as tex coord is same as 0.25. -0.825 -> 0.175. etc.
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// SL-13629
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// Unfortunately the texture is inverted, so we need to invert the y coord, but keep the 'interesting'
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// part within the same 0.175..0.250 range, i.e. d = (1 - d) - 1.575
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d = clamp(-0.575 - d, 0.0, 1.0);
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// With the colors in the lower 1/4 of the texture, inverting the coords leaves most of it inaccessible.
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// So, we can stretch the texcoord above the colors (ie > 0.25) to fill the entire remaining coordinate
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// space. This improves gradation, reduces banding within the rainbow interior. (1-0.25) / (0.425/0.25) = 4.2857
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float interior_coord = max(0.0, d - 0.25) * 4.2857;
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d = clamp(d, 0.0, 0.25) + interior_coord;
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float rad = (droplet_radius - 5.0f) / 1024.0f;
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return pow(texture2D(rainbow_map, vec2(rad+0.5, d)).rgb, vec3(1.8)) * moisture_level;
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}
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vec3 halo22(float d)
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{
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d = clamp(d, 0.1, 1.0);
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float v = sqrt(clamp(1 - (d * d), 0, 1));
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return texture2D(halo_map, vec2(0, v)).rgb * ice_level;
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}
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/// Soft clips the light with a gamma correction
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vec3 scaleSoftClip(vec3 light);
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void main()
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{
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// Potential Fill-rate optimization. Add cloud calculation
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// back in and output alpha of 0 (so that alpha culling kills
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// the fragment) if the sky wouldn't show up because the clouds
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// are fully opaque.
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vec4 color = vary_HazeColor;
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float rel_pos_lightnorm = vary_LightNormPosDot;
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float optic_d = rel_pos_lightnorm;
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vec3 halo_22 = halo22(optic_d);
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color.rgb += rainbow(optic_d);
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color.rgb += halo_22;
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color.rgb *= 2.;
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color.rgb = scaleSoftClip(color.rgb);
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// Gamma correct for WL (soft clip effect).
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frag_data[0] = vec4(color.rgb, 1.0);
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frag_data[1] = vec4(0.0,0.0,0.0,0.0);
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frag_data[2] = vec4(0.0,0.0,0.0,1.0); //1.0 in norm.w masks off fog
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gl_FragDepth = 0.99999f;
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}
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