/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019,
                2020, 2021 Vladimír Vondruš <mosra@centrum.cz>

    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.
*/

#ifdef MULTI_DRAW
#ifndef GL_ES
#extension GL_ARB_shader_draw_parameters: require
#else /* covers WebGL as well */
#extension GL_ANGLE_multi_draw: require
#endif
#endif

#ifndef NEW_GLSL
#define in attribute
#define out varying
#endif

#ifndef RUNTIME_CONST
#define const
#endif

/* Uniforms */

#ifndef UNIFORM_BUFFERS
#ifdef EXPLICIT_UNIFORM_LOCATION
layout(location = 0)
#endif
#ifdef TWO_DIMENSIONS
uniform highp mat3 transformationProjectionMatrix
    #ifndef GL_ES
    = mat3(1.0)
    #endif
    ;
#elif defined(THREE_DIMENSIONS)
uniform highp mat4 transformationProjectionMatrix
    #ifndef GL_ES
    = mat4(1.0)
    #endif
    ;
#else
#error
#endif

/* Uniform buffers */

#else
#ifdef EXPLICIT_UNIFORM_LOCATION
layout(location = 0)
#endif
uniform highp uint drawOffset
    #ifndef GL_ES
    = 0u
    #endif
    ;

layout(std140
    #ifdef EXPLICIT_BINDING
    , binding = 1
    #endif
) uniform TransformationProjection {
    highp
        #ifdef TWO_DIMENSIONS
        mat3
        #elif defined(THREE_DIMENSIONS)
        mat4
        #else
        #error
        #endif
    transformationProjectionMatrices[DRAW_COUNT];
};
#endif

/* Inputs */

#ifdef EXPLICIT_ATTRIB_LOCATION
layout(location = POSITION_ATTRIBUTE_LOCATION)
#endif
#ifdef TWO_DIMENSIONS
in highp vec2 position;
#elif defined(THREE_DIMENSIONS)
in highp vec4 position;
#else
#error
#endif

#ifdef EXPLICIT_ATTRIB_LOCATION
layout(location = COLOR_ATTRIBUTE_LOCATION)
#endif
in lowp vec4 color;

/* Outputs */

out lowp vec4 interpolatedColor;

void main() {
    #ifdef UNIFORM_BUFFERS
    #ifdef MULTI_DRAW
    highp uint drawId = drawOffset + uint(
        #ifndef GL_ES
        gl_DrawIDARB /* Using GL_ARB_shader_draw_parameters, not GLSL 4.6 */
        #else
        gl_DrawID
        #endif
        );
    #else
    #define drawId drawOffset
    #endif

    highp const
        #ifdef TWO_DIMENSIONS
        mat3
        #elif defined(THREE_DIMENSIONS)
        mat4
        #else
        #error
        #endif
        transformationProjectionMatrix = transformationProjectionMatrices[drawId];
    #endif

    #ifdef TWO_DIMENSIONS
    gl_Position.xywz = vec4(transformationProjectionMatrix*vec3(position, 1.0), 0.0);
    #elif defined(THREE_DIMENSIONS)
    gl_Position = transformationProjectionMatrix*position;
    #else
    #error
    #endif

    interpolatedColor = color;
}