//HUD VS 3 (mouse cursor).
// ---- Created with 3Dmigoto v1.3.16 on Sat Oct  2 12:12:44 2021

cbuffer vblock : register(b0)
{
  float4 mvpmatrixx : packoffset(c0);
  float4 mvpmatrixy : packoffset(c1);
  float4 mvpmatrixz : packoffset(c2);
  float4 mvpmatrixw : packoffset(c3);
}



// 3Dmigoto declarations
#define cmp -
Texture1D<float4> IniParams : register(t120);
Texture2D<float4> StereoParams : register(t125);
// Depth buffer copied to this input with 3Dmigoto:
// Texture2D<float> DepthBuffer : register(t110);
Texture2D<float> DepthBuffer : register(t110);



static const float near = 0.0001;
static const float far = 1;

float world_z_from_depth_buffer(float x, float y)
{
    uint width, height;
    float z;

    DepthBuffer.GetDimensions(width, height);

    x = min(max((x / 2 + 0.5) * width, 0), width - 1);
    y = min(max((-y / 2 + 0.5) * height, 0), height - 1);
    z = DepthBuffer.Load(int3(x, y, 0)).x;
    if (z == 1)
        return 0;

    return (far*near/((1-z)*near) + (far*z));
  // return z;
}

float adjust_from_depth_buffer(float x, float y)
{
    float4 stereo = StereoParams.Load(0);
	if (stereo.x==0) {return 0;}
    float separation = stereo.x; float convergence = stereo.y;
    float old_offset, offset, w, sampled_w, distance;
    uint i;

    // Stereo cursor: To improve the accuracy of the stereo cursor, we
    // sample a number of points on the depth buffer, starting at the near
    // clipping plane and working towards original x + separation.
    //
    // You can think of this as a line in three dimensional space that
    // starts at each eye and stretches out towards infinity. We sample 255
    // points along this line (evenly spaced in the X axis) and compare
    // with the depth buffer to find where the line is first intersected.
    //
    // Note: The reason for sampling 255 points came from a restriction in
    // DX9/SM3 where loops had to run a constant number of iterations and
    // there was no way to set that number from within the shader itself.
    // I'm not sure if the same restriction applies in DX11 with SM4/5 - if
    // it doesn't, we could change this to check each pixel instead for
    // better accuracy.
    //
    // Based on DarkStarSword's stereo crosshair code originally developed
    // for Miasmata, adapted to Unity, then translated to HLSL.

    offset = (near - convergence) * separation * 0; // Z = X offset from center
    distance = separation - offset;         // Total distance to cover (separation - starting X offset)

    old_offset = offset;
    for (i = 0; i < 500; i++) {
        offset += distance / 500.0;

        // Calculate depth for this point on the line:
        w = (separation * convergence*0.2525) / (separation - offset);

        sampled_w = world_z_from_depth_buffer(x + offset, y);
        if (sampled_w == 0)
            return separation;

        // If the sampled depth is closer than the calculated depth,
        // we have found something that intersects the line, so exit
        // the loop and return the last point that was not intersected:
        if (w > sampled_w)
            break;

        old_offset = offset;
    }

    return old_offset;
}

void main(
  float4 v0 : POSITION0,
  float2 v1 : TEXCOORD0,
  float4 v2 : COLOR0,
  out float4 o0 : COLOR0,
  out float4 o1 : TEXCOORD1,
  out float4 o2 : SV_Position0)
{
  float4 stereo = StereoParams.Load(0);
  float4 iniparams1 = IniParams.Load(int2(1,0));
  float4 iniparams3 = IniParams.Load(int2(3,0));
  float4 iniparams6 = IniParams.Load(int2(6,0));
  o0.xyzw = v2.xyzw;
  o1.xy = v1.xy;
  o1.zw = float2(0,0);
  o2.x = dot(v0.xyzw, mvpmatrixx.xyzw);
  o2.y = dot(v0.xyzw, mvpmatrixy.xyzw);
  o2.z = dot(v0.xyzw, mvpmatrixz.xyzw);
  o2.w = dot(v0.xyzw, mvpmatrixw.xyzw);
  if (iniparams1.z==1 && o2.w==1 && iniparams3.w!=5 && iniparams6.x!=1) {
    o2.x+=adjust_from_depth_buffer(0,0);
  } else if (o2.w==1 && iniparams3.w!=5) {
    o2.x+=stereo.x*iniparams1.y;
  }
  return;
}

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Generated by Microsoft (R) HLSL Shader Compiler 6.3.9600.16384
//
//   using 3Dmigoto v1.3.16 on Sat Oct  2 12:12:44 2021
//
//
// Buffer Definitions:
//
// cbuffer vblock
// {
//
//   float4 mvpmatrixx;                 // Offset:    0 Size:    16
//   float4 mvpmatrixy;                 // Offset:   16 Size:    16
//   float4 mvpmatrixz;                 // Offset:   32 Size:    16
//   float4 mvpmatrixw;                 // Offset:   48 Size:    16
//
// }
//
//
// Resource Bindings:
//
// Name                                 Type  Format         Dim Slot Elements
// ------------------------------ ---------- ------- ----------- ---- --------
// vblock                            cbuffer      NA          NA    0        1
//
//
//
// Input signature:
//
// Name                 Index   Mask Register SysValue  Format   Used
// -------------------- ----- ------ -------- -------- ------- ------
// POSITION                 0   xyzw        0     NONE   float   xyzw
// TEXCOORD                 0   xy          1     NONE   float   xy
// COLOR                    0   xyzw        2     NONE   float   xyzw
//
//
// Output signature:
//
// Name                 Index   Mask Register SysValue  Format   Used
// -------------------- ----- ------ -------- -------- ------- ------
// COLOR                    0   xyzw        0     NONE   float   xyzw
// TEXCOORD                 1   xyzw        1     NONE   float   xyzw
// SV_Position              0   xyzw        2      POS   float   xyzw
//
vs_5_0
dcl_globalFlags refactoringAllowed
dcl_constantbuffer cb0[4], immediateIndexed
dcl_input v0.xyzw
dcl_input v1.xy
dcl_input v2.xyzw
dcl_output o0.xyzw
dcl_output o1.xyzw
dcl_output_siv o2.xyzw, position
mov o0.xyzw, v2.xyzw
mov o1.xy, v1.xyxx
mov o1.zw, l(0,0,0,0)
dp4 o2.x, v0.xyzw, cb0[0].xyzw
dp4 o2.y, v0.xyzw, cb0[1].xyzw
dp4 o2.z, v0.xyzw, cb0[2].xyzw
dp4 o2.w, v0.xyzw, cb0[3].xyzw
ret
// Approximately 8 instruction slots used

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
