[[FX]]
<!--
// =================================================================================================
   Lightmap Shader
// =================================================================================================
-->

<Sampler id="albedoMap" />
<Sampler id="lightMap" />

<Context id="AMBIENT">
   <Shaders vertex="VS_GENERAL" fragment="FS_AMBIENT" />
</Context>

[[VS_GENERAL]]
// =================================================================================================

#include "shaders/utilityLib/vertCommon.glsl"

uniform vec3 viewer;
attribute vec2 texCoords0;
varying vec2 texCoords;

void main( void )
{
   // Calculate world space position
   vec4 pos = calcWorldPos( gl_Vertex );
   
   // Calculate texture coordinates and clip space position
   texCoords = texCoords0;
   gl_Position = gl_ModelViewProjectionMatrix * pos;
}

[[FS_AMBIENT]]   
// =================================================================================================

uniform sampler2D albedoMap;
uniform sampler2D lightMap;
varying vec2 texCoords;

void main( void )
{
   vec3 newCoords = vec3( texCoords, 0 );

   // Flip texture vertically to match the GL coordinate system
   newCoords.t *= -1.0;

   vec3 albedo = texture2D( albedoMap, newCoords.st ).rgb;
   vec3 light = texture2D( lightMap, newCoords.st ).rgb;
   
   gl_FragColor.rgb = albedo * light;
}

[[FX]]
<!--
// =================================================================================================
   Lightmap Shader
// =================================================================================================
-->

<Sampler id="albedoMap" />
<Sampler id="lightMap" />

<Context id="LIGHTING">
   <Shaders vertex="VS_GENERAL" fragment="FS_LIGHTING" />
   <RenderConfig writeDepth="false" blendMode="MULT" />
</Context>

<Context id="AMBIENT">
   <Shaders vertex="VS_GENERAL" fragment="FS_AMBIENT" />
</Context>

[[VS_GENERAL]]
// =================================================================================================

#include "shaders/utilityLib/vertCommon.glsl"

uniform vec3 viewer;
attribute vec2 texCoords0;
attribute vec3 normal;

varying vec4 pos, vsPos;
varying vec2 texCoords;
varying vec3 tsbNormal;

void main( void )
{
   // Calculate normal
   tsbNormal = calcWorldVec( normal );

   // Calculate world space position
   pos = calcWorldPos( gl_Vertex );

   vsPos = calcViewPos( pos );
   
   // Calculate texture coordinates and clip space position
   texCoords = texCoords0;
   gl_Position = gl_ModelViewProjectionMatrix * pos;
}

[[FS_LIGHTING]]
// =================================================================================================

#include "shaders/utilityLib/fragLighting.glsl" />

uniform sampler2D albedoMap;
uniform sampler2D lightMap;

varying vec4 pos, vsPos;
varying vec2 texCoords;
varying vec3 tsbNormal;

vec3 calcLightmapShadow( const vec3 pos, const vec3 normal, const float viewDist, const float ambientIntensity )
{
   vec3 light = lightPos.xyz - pos;
   
   // Distance
   float lightDist = length( light ) / lightPos.w;
   light = normalize( light );
   
   // Light intensity
   vec3 col = vec3(1,1,1);
   
   // Shadow
   if( dot( normal, light ) > 0.0)
   {   
    vec4 projShadow = shadowMats[3] * vec4( pos, 1.0 );
    if( viewDist < shadowSplitDists.x ) projShadow = shadowMats[0] * vec4( pos, 1.0 );
    else if( viewDist < shadowSplitDists.y ) projShadow = shadowMats[1] * vec4( pos, 1.0 );
    else if( viewDist < shadowSplitDists.z ) projShadow = shadowMats[2] * vec4( pos, 1.0 );
   
    projShadow.z = lightDist;
    projShadow.xy /= projShadow.w;
   
    float shadowFac = PCF( projShadow );
    col *= max( shadowFac, ambientIntensity );
  }
   
   return col;
}

void main( void )
{
   vec3 newCoords = vec3( texCoords, 0 );
   
   // Flip texture vertically to match the GL coordinate system
   newCoords.t *= -1.0;

   vec3 normal = tsbNormal;
   vec3 newPos = pos.xyz;
   
   gl_FragColor.rgb = calcLightmapShadow( newPos, normalize( normal ), -vsPos.z, 0.3 );
}

[[FS_AMBIENT]]   
// =================================================================================================

#include "shaders/utilityLib/fragLighting.glsl" />

uniform sampler2D albedoMap;
uniform sampler2D lightMap;

varying vec4 pos;
varying vec2 texCoords;

void main( void )
{
   vec3 newCoords = vec3( texCoords, 0 );

   // Flip texture vertically to match the GL coordinate system
   newCoords.t *= -1.0;

   vec3 albedo = texture2D( albedoMap, newCoords.st ).rgb;
   vec3 light = texture2D( lightMap, newCoords.st ).rgb;
   
   gl_FragColor.rgb = albedo * light;
}