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// ----------------------------------------------------------------------------
// Copyright (c) 2014, Nicolas P. Rougier. All Rights Reserved.
// Distributed under the (new) BSD License.
// ----------------------------------------------------------------------------
uniform vec4 viewport_local;
uniform vec4 viewport_global;
uniform int viewport_transform;
uniform int viewport_clipping;
#ifdef __VERTEX_SHADER__
void transform(void)
{
if (viewport_transform == 0) return;
vec4 position = gl_Position;
float w = viewport_local.z / viewport_global.z;
float h = viewport_local.w / viewport_global.w;
float x = 2.0*(viewport_local.x / viewport_global.z) - 1.0 + w;
float y = 2.0*(viewport_local.y / viewport_global.w) - 1.0 + h;
gl_Position = vec4((x + w*position.x/position.w)*position.w,
(y + h*position.y/position.w)*position.w,
position.z, position.w);
}
#endif
#ifdef __FRAGMENT_SHADER__
void clipping(void)
{
// if (viewport_clipping == 0) return;
vec2 position = gl_FragCoord.xy;
if( position.x < (viewport_local.x)) discard;
else if( position.x > (viewport_local.x+viewport_local.z)) discard;
else if( position.y < (viewport_local.y)) discard;
else if( position.y > (viewport_local.y+viewport_local.w)) discard;
/*
if( length(position.x - viewport_local.x) < 1.0 )
gl_FragColor = vec4(0,0,0,1);
else if( length(position.x - viewport_local.x - viewport_local.z) < 1.0 )
gl_FragColor = vec4(0,0,0,1);
else if( length(position.y - viewport_local.y) < 1.0 )
gl_FragColor = vec4(0,0,0,1);
else if( length(position.y - viewport_local.y - viewport_local.w) < 1.0 )
gl_FragColor = vec4(0,0,0,1);
*/
}
#endif
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