#version 410 compatibility
#define SMAA_PIXEL_SIZE vec2(1.0 / 512.0, 1.0 / 512.0)

#define SMAA_THRESHOLD 0.05
#define SMAA_MAX_SEARCH_STEPS 32
#define SMAA_MAX_SEARCH_STEPS_DIAG 16
#define SMAA_CORNER_ROUNDING 25


#ifndef SMAA_DEPTH_THRESHOLD
#define SMAA_DEPTH_THRESHOLD (0.1 * SMAA_THRESHOLD)
#endif


#ifndef SMAA_REPROJECTION
#define SMAA_REPROJECTION 0
#endif

#define SMAA_REPROJECTION_WEIGHT_SCALE 30.0


#ifndef SMAA_AREATEX_MAX_DISTANCE
#define SMAA_AREATEX_MAX_DISTANCE 16
#endif
#ifndef SMAA_AREATEX_MAX_DISTANCE_DIAG
#define SMAA_AREATEX_MAX_DISTANCE_DIAG 20
#endif
#define SMAA_AREATEX_PIXEL_SIZE (1.0 / vec2(160.0, 560.0))
#define SMAA_AREATEX_SUBTEX_SIZE (1.0 / 7.0)


/* --- Define section is over ---- */

/**
 * Blend Weight Calculation Vertex Shader
 */
void SMAABlendingWeightCalculationVS(vec4 position,
                                     out vec4 svPosition,
                                     inout vec2 texcoord,
                                     out vec2 pixcoord,
                                     out vec4 offset[3]) {
    svPosition = position;

    pixcoord = texcoord / SMAA_PIXEL_SIZE;

    // We will use these offsets for the searches later on (see @PSEUDO_GATHER4):
    offset[0] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * vec4(-0.25, -0.125,  1.25, -0.125);
    offset[1] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * vec4(-0.125, -0.25, -0.125,  1.25);

    // And these for the searches, they indicate the ends of the loops:
    offset[2] = vec4(offset[0].xz, offset[1].yw) + 
                vec4(-2.0, 2.0, -2.0, 2.0) *
                SMAA_PIXEL_SIZE.xxyy * float(SMAA_MAX_SEARCH_STEPS);
}

/* ------------- Header is over -------------- */

out vec2 texcoord;
out vec2 pixcoord;
out vec4 offset[3];
out vec4 dummy2;

attribute vec3 vPosition;
attribute vec2 vTexCoord;
uniform mat4 ProjectionMatrix;


void main()
{
  texcoord = vTexCoord;
  vec4 dummy1 = vec4(0);
  SMAABlendingWeightCalculationVS(dummy1, dummy2, texcoord, pixcoord, offset);
  gl_Position = ProjectionMatrix * vec4(vPosition.xyz, 1.0);
}