#version 450
#extension GL_KHR_vulkan_glsl : enable

//#include "ShaderDescriptorDefinitions.glsl"


// vertex inputs
layout(location = 0) in vec4 positionalOffset;
layout(location = 1) in uint glyphIndex;

// between shader stages
layout(location = 0) out struct
{
  vec4 vertPos; // location 0
  vec2 uv; // location = 1
  vec4 normal; // location = 2

} Out;

// material stuff
layout(location = 3) out struct
{
  uint eid;
  vec3 textColor;
} Out2;

// Camera data
layout(set = 2, binding = 0) uniform CameraData
{
  vec4 position; 
  mat4 vpMat;
  mat4 viewMat;
  mat4 projMat;
} cameraData;

// push constants
layout(std140, push_constant) uniform TestPushConstant
{
  mat4 worldTransform;
  uint eid;
  vec3 textColor;

} testPushConstant;

// Descriptor sets
layout(std430, set = 4, binding = 1) buffer GlyphTransforms
{
  mat4 matrices[];
} glyphTransforms;

vec2 CreateQuad(in uint vertexID)
{
  uint b = 1 << vertexID;
  return vec2 ((0x3 & b) != 0, (0x9 & b) != 0);
}

void main()
{
  // write EID data to FS
  Out2.eid = testPushConstant.eid;

  // local variable for font index
  uint fontIndex = glyphIndex;

  // get font data
  mat4 fontData = glyphTransforms.matrices[fontIndex];

  // Generate UV coords and vertex positions
  Out.uv = CreateQuad(gl_VertexIndex);
  vec3 vertexPos = vec3(Out.uv, 0.0f);

  // Get the local matrices
  mat4 localModel = testPushConstant.worldTransform;

  //mat4 uiScale = mat4(1.0f);
  //uiScale[0][0] = cameraData.cameraRight / 20.49f;
  //uiScale[1][1] = cameraData.cameraTop / 11.323f;

  // transform the UV to atlas space to sample the font bitmap correctly
  Out.uv = vec2(mat3(fontData) * vec3(Out.uv, 1.0f));

  // Matrix to transform the quad from local to font space (for a font to be of correct size)
  mat3 toFontSpace = mat3(1.0f);
  toFontSpace[0][0] = fontData[3][0];
  toFontSpace[1][1] = fontData[3][1];
  toFontSpace[2][0] = positionalOffset.x;
  toFontSpace[2][1] = positionalOffset.y;

  // Initialize variables for use in FS
  //characterIndex = gl_InstanceID; 

  // Transform the vertices to font space
  vertexPos = toFontSpace * vec3(vertexPos.xy, 1.0f); 

  Out2.textColor = testPushConstant.textColor;

  // transform the vertex position to font space
  gl_Position = cameraData.projMat * localModel * vec4(vertexPos, 1.0f);
  // gl_Position = vec4(vertexPos, 1.0f);
}