140 lines
5.0 KiB
GLSL
140 lines
5.0 KiB
GLSL
#version 120
|
|
/*
|
|
-----------------------------------------------------------------------------
|
|
This source file is part of OGRE
|
|
(Object-oriented Graphics Rendering Engine)
|
|
For the latest info, see http://www.ogre3d.org
|
|
|
|
Copyright (c) 2000-2012 Torus Knot Software Ltd
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
of this software and associated documentation files (the "Software"), to deal
|
|
in the Software without restriction, including without limitation the rights
|
|
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
copies of the Software, and to permit persons to whom the Software is
|
|
furnished to do so, subject to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included in
|
|
all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
THE SOFTWARE.
|
|
-----------------------------------------------------------------------------
|
|
*/
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Program Name: FFPLib_Fog
|
|
// Program Desc: Fog functions of the FFP.
|
|
// Program Type: Vertex/Pixel shader
|
|
// Language: GLSL
|
|
// Notes: Implements core functions needed by FFPFog class.
|
|
// Based on fog engine.
|
|
// See http://msdn.microsoft.com/en-us/library/bb173398.aspx
|
|
// Vertex based fog: the w component of the out position is used
|
|
// as the distance parameter to fog formulas. This is basically the z coordinate
|
|
// in world space. See pixel fog under D3D docs. The fog factor is computed according
|
|
// to each formula, then clamped and output to the pixel shader.
|
|
// Pixel based fog: the w component of the out position is passed to pixel shader
|
|
// that computes the fog factor based on it.
|
|
// Both techniques use the fog factor in the end of the pixel shader to blend
|
|
// the output color with the fog color.
|
|
//-----------------------------------------------------------------------------
|
|
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
void FFP_VertexFog_Linear(in mat4 mWorldViewProj,
|
|
in vec4 pos,
|
|
in vec4 fogParams,
|
|
out float oFogFactor)
|
|
{
|
|
vec4 vOutPos = mWorldViewProj * pos;
|
|
float distance = abs(vOutPos.w);
|
|
float fogFactor = (fogParams.z - distance) * fogParams.w;
|
|
|
|
oFogFactor = clamp(fogFactor, 0.0, 1.0);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
void FFP_VertexFog_Exp(in mat4 mWorldViewProj,
|
|
in vec4 pos,
|
|
in vec4 fogParams,
|
|
out float oFogFactor)
|
|
{
|
|
vec4 vOutPos = mWorldViewProj * pos;
|
|
float distance = abs(vOutPos.w);
|
|
float exp = distance*fogParams.x;
|
|
float fogFactor = 1.0 / pow(2.71828, exp);
|
|
|
|
oFogFactor = clamp(fogFactor, 0.0, 1.0);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
void FFP_VertexFog_Exp2(in mat4 mWorldViewProj,
|
|
in vec4 pos,
|
|
in vec4 fogParams,
|
|
out float oFogFactor)
|
|
{
|
|
vec4 vOutPos = mWorldViewProj * pos;
|
|
float distance = abs(vOutPos.w);
|
|
float exp = (distance*fogParams.x*distance*fogParams.x);
|
|
float fogFactor = 1.0 / pow(2.71828, exp);
|
|
|
|
oFogFactor = clamp(fogFactor, 0.0, 1.0);
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
void FFP_PixelFog_Depth(in mat4 mWorldViewProj,
|
|
in vec4 pos,
|
|
out float oDepth)
|
|
{
|
|
vec4 vOutPos = mWorldViewProj * pos;
|
|
oDepth = vOutPos.w;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
void FFP_PixelFog_Linear(in float depth,
|
|
in vec4 fogParams,
|
|
in vec4 fogColor,
|
|
in vec4 baseColor,
|
|
out vec4 oColor)
|
|
{
|
|
float distance = abs(depth);
|
|
float fogFactor = clamp((fogParams.z - distance) * fogParams.w, 0.0, 1.0);
|
|
|
|
oColor = mix(fogColor, baseColor, fogFactor);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
void FFP_PixelFog_Exp(in float depth,
|
|
in vec4 fogParams,
|
|
in vec4 fogColor,
|
|
in vec4 baseColor,
|
|
out vec4 oColor)
|
|
{
|
|
float distance = abs(depth);
|
|
float exp = (distance*fogParams.x);
|
|
float fogFactor = clamp(1.0 / pow(2.71828, exp), 0.0, 1.0);
|
|
|
|
oColor = mix(fogColor, baseColor, fogFactor);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
void FFP_PixelFog_Exp2(in float depth,
|
|
in vec4 fogParams,
|
|
in vec4 fogColor,
|
|
in vec4 baseColor,
|
|
out vec4 oColor)
|
|
{
|
|
float distance = abs(depth);
|
|
float exp = (distance*fogParams.x*distance*fogParams.x);
|
|
float fogFactor = clamp(1.0 / pow(2.71828, exp), 0.0, 1.0);
|
|
|
|
oColor = mix(fogColor, baseColor, fogFactor);
|
|
}
|