/**
 * QUIK: User Interface Kit
 * Copyright (C) 2023 Halit Utku Maden, et al.
 */
#version 130

in vec2  v2Position;     /**< The vertex position.*/
in float fZIndex;        /**< The z index. */
in vec2  v2TexPos;       /**< The texture coorindates. */
in float fTexLayer;      /**< The texture layer for 3D textures. */
in vec4  v4Color;        /**< The vertex color. */

out vec2    fv2TexPos;
out float   ffTexLayer;
out vec4    fv4Color;

uniform mat4        m4Transforms;   /**< The view matrix. */
uniform float       fMaxZ;          /**< Highest Z coordinate. */

const mat4 m4BaseTransforms = mat4(
    vec4( 2.0,  0.0,  0.0,  0.0),
    vec4( 0.0, -2.0,  0.0,  0.0),
    vec4( 0.0,  0.0,  1.0,  0.0),
    vec4(-1.0,  1.0,  0.0,  1.0)
);

void main(void)
{
    vec4 v      = vec4(v2Position, fZIndex/fMaxZ, 1);
    gl_Position = m4Transforms * v;

    fv2TexPos = v2TexPos;
    fv4Color = v4Color;
    ffTexLayer = fTexLayer;
}