map_grass

function widget:GetInfo()
  return {
    name      = "Map Grass GL4",
    version   = "v0.001",
    desc      = "Instanced rendering of garbagegrass",
    author    = "Beherith",
    date      = "2021.04.12",
    license   = "CC-BY-NC-ND 4.0",
    layer     = -1000000000000,
    enabled   = true,
  }
end

--------------------------------------------------------------------------------
-- Todo:
-- a func that collects all map grass patches into VBO
-- a way to draw a textured quad
-- blade texture
-- normals texture?
-- a nice grass patch VBO
  -- pos
  -- uv
  -- normal
  -- bitangent
  -- tangent
-- a vao drawing func preunit
-- sample $grass for color in VS
-- sample a noise texture in VS
-- sway grass with wind
-- 
--------------------------------------------------------------------------------
local patchresolution = 24
local patchsizemult = 1.0
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

local spGetGroundHeight = Spring.GetGroundHeight
local spGetGrass = Spring.GetGrass 
local floor = math.floor
local mapSizeX, mapSizeZ = Game.mapSizeX, Game.mapSizeZ

---------------------------VAO VBO stuff:---------------------------------------

local grassPatchVBO = nil
local grassInstanceVBO = nil
local grassInstanceVBOSize = nil
local grassVAO = nil
local grassShader = nil
local grassPatchCount = 0
local luaShaderDir = "LuaUI/Widgets/Include/"
local LuaShader = VFS.Include(luaShaderDir.."LuaShader.lua")


local grassBladeColorTex = "LuaUI/Images/luagrass/grass_field_medit_flowering.dds.cached.dds" -- rgb + alpha transp
local grassBladeNormalTex = "LuaUI/Images/luagrass/grass_field_medit_flowering.dds.cached.dds" -- xyz + specular factor
local mapGrassColorModTex = "$grass"
local grassWindPerturbTex = "bitmaps/Lups/perlin_noise.jpg" -- rgba of various frequencies of perlin noise?

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

local function UpdateShader()
	grassShader:ActivateWith(function()
		grassShader:SetUniformAlways("shaderParams", gridSize, brightness, (curvature and 1.0) or 0.0, (fogEffect and 1.0) or 0.0)
	end)
end

local function goodbye(reason)
  Spring.Echo("Map Grass GL4 widget exiting with reason: "..reason)
  if grassPatchVBO then grassPatchVBO = nil end
  if grassInstanceVBO then grassInstanceVBO = nil end
  if grassVAO then grassVAO = nil end
  if grassShader then grassShader:Finalize() end
  widgetHandler:RemoveWidget(self)
end
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- using: http://ogldev.atspace.co.uk/www/tutorial33/tutorial33.html
local function makeGrassPatchVBO() -- this needs to be much better
  grassPatchVBO = gl.GetVBO(GL.ARRAY_BUFFER,true)
  if grassPatchVBO == nil then goodbye("No LuaVAO support") end
  
  local VBOLayout= {  {id = 0, name = "position", size = 3},
      {id = 1, name = "normal", size = 3},
      {id = 2, name = "stangent", size = 3},
      {id = 3, name = "ttangent", size = 3},
      {id = 4, name = "texcoords0", size = 2},
      {id = 5, name = "texcoords1", size = 2},
      {id = 6, name = "pieceindex", size = 1},} --khm, this should be unsigned int
    
local VBOData = { 	19.9253,-0.3833,-5.5756,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	-15.0340,-0.3833,14.6081,0,1.0000,0,0,0,0,0,0,0,0.0019,0.0028,0,0,0,
	-11.7273,16.8366,20.3354,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	-11.7273,16.8366,20.3354,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	23.2319,16.8365,0.1517,0,1.0000,0,0,0,0,0,0,0,0.9984,0.9976,0,0,0,
	19.9253,-0.3833,-5.5756,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	-14.8705,-0.3833,14.8913,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	20.0888,-0.3833,-5.2924,0,1.0000,0,0,0,0,0,0,0,0.0019,0.0028,0,0,0,
	16.7821,16.8365,-11.0198,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	16.7821,16.8365,-11.0198,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	-18.1772,16.8365,9.1640,0,1.0000,0,0,0,0,0,0,0,0.9984,0.9976,0,0,0,
	-14.8705,-0.3833,14.8913,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	19.8347,-0.3833,4.6970,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	-15.1245,-0.3833,-15.4867,0,1.0000,0,0,0,0,0,0,0,0.0019,0.0028,0,0,0,
	-18.4312,16.8366,-9.7594,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	-18.4312,16.8366,-9.7594,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	16.5280,16.8365,10.4243,0,1.0000,0,0,0,0,0,0,0,0.9984,0.9976,0,0,0,
	19.8347,-0.3833,4.6970,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	-15.2880,-0.3833,-15.2036,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	19.6712,-0.3833,4.9802,0,1.0000,0,0,0,0,0,0,0,0.0019,0.0028,0,0,0,
	22.9779,16.8365,-0.7471,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	22.9779,16.8365,-0.7471,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	-11.9814,16.8365,-20.9309,0,1.0000,0,0,0,0,0,0,0,0.9984,0.9976,0,0,0,
	-15.2880,-0.3833,-15.2036,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	-6.1704,-0.3833,20.5802,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	-6.1704,-0.3833,-19.7872,0,1.0000,0,0,0,0,0,0,0,0.0019,0.0028,0,0,0,
	-12.7837,16.8366,-19.7872,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	-12.7837,16.8366,-19.7872,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	-12.7837,16.8365,20.5802,0,1.0000,0,0,0,0,0,0,0,0.9984,0.9976,0,0,0,
	-6.1704,-0.3833,20.5802,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	-6.4974,-0.3833,-19.7872,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
	-6.4974,-0.3833,20.5802,0,1.0000,0,0,0,0,0,0,0,0.0019,0.0028,0,0,0,
	0.1159,16.8365,20.5802,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	0.1159,16.8365,20.5802,0,1.0000,0,0,0,0,0,0,0,0.0019,0.9976,0,0,0,
	0.1159,16.8365,-19.7872,0,1.0000,0,0,0,0,0,0,0,0.9984,0.9976,0,0,0,
	-6.4974,-0.3833,-19.7872,0,1.0000,0,0,0,0,0,0,0,0.9984,0.0028,0,0,0,
}
  local numVerts = 36
  
  grassPatchVBO:Define(
    numVerts, -- 3 verts, just a triangle for now
    VBOLayout -- 17 floats per vertex
    )
  grassPatchVBO:Upload(VBOData)
end

local function makeGrassInstanceVBO()
  grassInstanceVBO = gl.GetVBO(GL.ARRAY_BUFFER,true)
  if grassInstanceVBO == nil then  goodbye("No LuaVAO support") end
  
  grassInstanceData= {}
  
  for x = patchresolution / 2, Game.mapSizeX, patchresolution do
    for z = patchresolution / 2, Game.mapSizeZ, patchresolution do
      if spGetGrass(x,z) == 1 or true then -- TESTING BY GRASS EVERYWHERE
        local lx = x + (math.random() -0.5) * patchresolution/2
        local lz = z + (math.random() -0.5) * patchresolution/2
        
        local gx, gy, gz, gs = Spring.GetGroundNormal (lx,lz )
        local gh = spGetGroundHeight(lx,lz)
        
        if gh > 55 and gy > 0.98 then
          grassPatchCount = grassPatchCount + 1
          grassInstanceData[#grassInstanceData+1] = lx 
          grassInstanceData[#grassInstanceData+1] = gh
          grassInstanceData[#grassInstanceData+1] = lz
          grassInstanceData[#grassInstanceData+1] = (1.0 + math.random()) * patchsizemult -- size 
          --Spring.Echo(x,gh,z)
          grassInstanceData[#grassInstanceData+1] = math.random()
          grassInstanceData[#grassInstanceData+1] = math.random()*6
          grassInstanceData[#grassInstanceData+1] = math.random()
          grassInstanceData[#grassInstanceData+1] = math.random() --  
        end
      end
    end
  end
  Spring.Echo("Drawing ",#grassInstanceData/8,"grass patches")
  grassInstanceVBO:Define(
    #grassInstanceData/8,--?we dont know how big yet!
    {
      {id = 7, name = 'instancepos', size = 4}, -- a vec4 for pos + random rotation
      {id = 8, name = 'instancerot', size = 4}, -- a vec4 for pos + random rotation
      }
    )
  grassInstanceVBO:Upload(grassInstanceData)
end

local vsSrc = [[
#version 420
#line 10065

layout (location = 0) in vec3 vertexPos;
layout (location = 1) in vec3 vertexNormal;
layout (location = 2) in vec3 stangent;
layout (location = 3) in vec3 ttangent;
layout (location = 4) in vec2 texcoords0;
layout (location = 5) in vec2 texcoords1;
layout (location = 6) in float pieceindex;
layout (location = 7) in vec4 instancePos; //x, y, z, size
layout (location = 8) in vec4 instanceRot; //x, y, z, rot

uniform vec4 grassShaderParams; // grass X offset, grass wind Y offset, grass wind speed

uniform sampler2D grassBladeColorTex;
uniform sampler2D grassBladeNormalTex;
uniform sampler2D mapGrassColorModTex;
uniform sampler2D grassWindPerturbTex;

out DataVS {
	vec3 worldPos;
  vec3 Normal;
  vec2 texCoord0;
  vec3 Tangent;
  vec3 Bitangent;
  vec4 mapColor;
  vec4 grassNoise;
  vec4 instanceParamsVS;
};

layout(std140, binding = 0) uniform UniformMatrixBuffer {
  mat4 screenView;
  mat4 screenProj;
  mat4 screenViewProj;

  mat4 cameraView;
  mat4 cameraProj;
  mat4 cameraViewProj;
  mat4 cameraBillboardProj;

	mat4 cameraViewInv;
	mat4 cameraProjInv;
	mat4 cameraViewProjInv;
  // the rest are not useful now
};

layout(std140, binding = 1) uniform UniformParamsBuffer {
  vec3 rndVec3; //new every draw frame.
  uint renderCaps; //various render booleans

  vec4 timeInfo; //gameFrame, gameSeconds, drawFrame, frameTimeOffset
  vec4 viewGeometry; //vsx, vsy, vpx, vpy
  vec4 mapSize; //xz, xzPO2

  vec4 fogColor; //fog color
  vec4 fogParams; //fog {start, end, 0.0, scale}
  
  vec4 pad[6];
  
  vec4 windInfo;
};

// glsl rotate convencience funcs: https://github.com/dmnsgn/glsl-rotate

mat4 rotation3dY(float a) {
	float s = sin(a);
	float c = cos(a);

	return mat4(
		  c, 0.0,  -s, 0.0,
		0.0, 1.0, 0.0, 0.0,
		  s, 0.0,   c, 0.0,
		0.0, 0.0, 0.0, 1.0
	);
}

mat4 scaleMat(vec3 s) {
	return mat4(
		s.x, 0.0, 0.0, 0.0,
		0.0, s.y, 0.0, 0.0,
		0.0, 0.0, s.z, 0.0,
		0.0, 0.0, 0.0, 1.0
	);
}

mat4 translationMat(vec3 t) {
	return mat4(
		1.0, 0.0, 0.0, 0.0,
		0.0, 1.0, 0.0, 0.0,
		0.0, 0.0, 1.0, 0.0,
		t.x, t.y, t.z, 1.0
	);
}

#line 10275


#define windSampleScale 0.001

void main() {
  
  mat4 R = rotation3dY(instanceRot.y);
  mat4 S = scaleMat(instancePos.www);
  mat4 T = translationMat(instancePos.xyz);
  mat4 worldMat = T * R * S;
  mat4 invWorldMat = transpose(worldMat);
  
  vec4 myVertexPos = vec4(vertexPos, 1.0); 
  myVertexPos.xyz += mat3(invWorldMat) * normalize(windInfo.xyz) * sqrt(max(vertexPos.y, 0.0)) * smoothstep(-3.0, 20.0, windInfo.w) * 3.0;
  vec4 grassVertWorldPos = worldMat * myVertexPos;
  
  //grassVertWorldPos.xyz += instancePos.xyz; // rotate Y and move to world pos
  
  mapColor = texture(mapGrassColorModTex, vec2(grassVertWorldPos.x / mapSize.x, grassVertWorldPos.z / mapSize.z)); // sample minimap
  
  grassNoise = texture(grassWindPerturbTex, vec2((grassVertWorldPos.xz + vec2(timeInfo.y*10)) * windSampleScale)); // sample windnoise
  grassNoise = (grassNoise - 0.5 );
  
  //vec4 worldpos = vec4(myVertexPos.xyz + instanceparams.xyz, 1.0); what is this?
  
  grassVertWorldPos.xyz = grassVertWorldPos.xyz +  grassNoise.rgb * myVertexPos.y * instancePos.w; // add temp ez-wind for now
  
  // ------------ dump the stuff for FS --------------------
  texCoord0 = texcoords0;
  Normal = mat3(R) * vertexNormal;
  Tangent = mat3(R) * ttangent;
  mat4 mat = cameraView;
  //mat[0].xyz = vec3(1, 0, 0);
  //mat[1].xyz = vec3(0, 1, 0);
  //mat[2].xyz = vec3(0, 0, 1);
  
  gl_Position = cameraProj * mat * grassVertWorldPos;
}
]]

local fsSrc = [[
#version 330

#extension GL_ARB_uniform_buffer_object : require
#extension GL_ARB_shading_language_420pack: require

uniform vec4 grassShaderParams; // grass X offset, grass wind Y offset, grass wind speed

uniform sampler2D grassBladeColorTex;
uniform sampler2D grassBladeNormalTex;
uniform sampler2D mapGrassColorModTex;
uniform sampler2D grassWindPerturbTex;

in DataVS {
	vec3 worldPos;
  vec3 Normal;
  vec2 texCoord0;
  vec3 Tangent;
  vec3 Bitangent;
  vec4 mapColor;
  vec4 grassNoise;
  vec4 instanceParamsVS;
};

layout(std140, binding = 0) uniform UniformMatrixBuffer {
  mat4 screenView;
  mat4 screenProj;
  mat4 screenViewProj;

  mat4 cameraView;
  mat4 cameraProj;
  mat4 cameraViewProj;
  mat4 cameraBillboardProj;

	mat4 cameraViewInv;
	mat4 cameraProjInv;
	mat4 cameraViewProjInv;
  // the rest are not useful now
};

layout(std140, binding = 1) uniform UniformParamsBuffer {
  vec3 rndVec3; //new every draw frame.
  uint renderCaps; //various render booleans

  vec4 timeInfo; //gameFrame, gameSeconds, drawFrame, frameTimeOffset
  vec4 viewGeometry; //vsx, vsy, vpx, vpy
  vec4 mapSize; //xz, xzPO2

  vec4 fogColor; //fog color
  vec4 fogParams; //fog {start, end, 0.0, scale}
  
  vec4 pad[6];
  
  vec4 windInfo;
};

out vec4 fragColor;

void main() {
	fragColor = texture(grassBladeColorTex, texCoord0);
  fragColor.rgb = mix(fragColor.rgb,mapColor.rgb,1.0-texCoord0.y); //more mappy color at bottom of grass
  fragColor.rgb = fragColor.rgb * clamp(texCoord0.y+0.5,0.5,1.0); // darken the bottom of it
  fragColor.a = clamp((fragColor.a - 0.5) * 1.0 + 0.5,0.0,1.0); // harden alpha
	//fragColor.rgb = mix(fogColor.rgb, fragColor.rgb, alphaFog.y);
	//ragColor.a = alphaFog.x;
  //fragColor = vec4(1.0, 1.0, 1.0, 1.0);
  //fragColor = vec4(mapColor.rgb*texCoord0.x,1.0);
  if (fragColor.a < 0.3)
	discard;
}
]]

local function makeShaderVAO()
  grassVAO = gl.GetVAO()
  if grassVAO == nil then goodbye("Failed to create grassVAO") end
  
  grassShader = LuaShader(
    {
      vertex = vsSrc,
      fragment = fsSrc,
      --geometry = gsSrc, no geom shader for now
      uniformInt = {
        grassBladeColorTex = 0,-- rgb + alpha transp
        grassBladeNormalTex = 1,-- xyz + specular factor
        mapGrassColorModTex = 2, -- minimap
        grassWindPerturbTex = 3, -- perlin
        },
      uniformFloat = {
        grassUniforms = {1,1,1,1},
      },
    },
    "GrassShaderGL4"
  )
  shaderCompiled = grassShader:Initialize()
  if not shaderCompiled then goodbye("Failed to compile grassShader GL4 ") end

  grassVAO:AttachVertexBuffer(grassPatchVBO)
  grassVAO:AttachInstanceBuffer(grassInstanceVBO)
end


function widget:Initialize()
	WG['grassgl4'] = {}
	WG['grassgl4'].getBrightness = function()
		return brightness
	end
	WG['grassgl4'].setBrightness = function(value)
		brightness = value
	end
	WG['grassgl4'].getCurvature = function()
		return curvature
	end
	WG['grassgl4'].setCurvature = function(value)
		curvature = value
	end
  
  makeGrassPatchVBO()
  makeGrassInstanceVBO()
  makeShaderVAO()
end


-- depth defaults:
--[[
	false
	false
	GL_DEPTH_FUNC = GL_ALWAYS
]]--
-- blending defaults:
--[[
	true
	GL_SRC_ALPHA
	GL_ONE_MINUS_SRC_ALPHA
]]--
-- culling defaults
--[[
	false
	GL_CULL_FACE_MODE = GL_BACK
]]--
function widget:DrawWorldPreUnit()

	gl.DepthTest(GL.LEQUAL)
	--gl.DepthTest(false)
	--gl.AlphaToCoverage(true)
	gl.DepthMask(true)
	gl.Culling(GL.BACK) -- needs better front and back instead of using this

	gl.Texture(0, grassBladeColorTex)
	gl.Texture(1, "$grass")
	gl.Texture(2, "$grass")
	gl.Texture(3, grassWindPerturbTex)
	grassShader:Activate()

  --Spring.Echo(grassPatchCount)
  grassVAO:DrawArrays(GL.TRIANGLES, 36, 0, grassPatchCount)

	grassShader:Deactivate()
	gl.Texture(0, false)
	gl.Texture(1, false)
	gl.Texture(2, false)
	gl.Texture(3, false)

	gl.DepthTest(GL.ALWAYS)
	gl.DepthMask(false)
	gl.AlphaToCoverage(false)
	gl.Culling(GL.BACK)
end

function widget:GetConfigData(data)
	return {
		brightness = brightness,
		curvature = curvature,
		fogEffect = fogEffect
	}
end

function widget:SetConfigData(data)
	if data.brightness ~= nil then
		brightness = data.brightness
	end
	if data.curvature ~= nil then
		curvature = data.curvature
	end
	if data.fogEffect ~= nil then
		fogEffect = data.fogEffect
	end
end
-- ahahahah you cant stop me:
--[[

import sys

normals_up = True
if len(sys.argv) <2:
	sys.argv.append("tovbo.obj")

objdata = {'vn' : [], 'vt' : [], 'v' : []}
numverts = 0

outfile = open(sys.argv[1]+'.lua','w')
outfile.write("""local VBOLayout= {  {id = 0, name = "position", size = 3},
      {id = 1, name = "normal", size = 3},
      {id = 2, name = "stangent", size = 3},
      {id = 3, name = "ttangent", size = 3},
      {id = 4, name = "texcoords0", size = 2},
      {id = 5, name = "texcoords1", size = 2},
      {id = 6, name = "pieceindex", size = 1},} --khm, this should be unsigned int
local VBOData = { """)

def listoffloats_to_line(lof):
	return '\t' + ','.join("0" if f == 0 else '%.4f'%f for f in lof) + ',\n'

for objline in open(sys.argv[1]).readlines():
	objitems = objline.strip().split()
	if objitems[0] in objdata:
		objdata[objitems[0] ].append(list(map(float,objitems[1:])))
	if objitems[0] == 'f':
		for objitem in objitems[1:4]:
			vi, vti, vni = tuple(map(int,objitem.split('/')))
			if normals_up:
				vn = [0,1,0]
			else:
				vn = objdata['vn'][vni-1]
			outfile.write(listoffloats_to_line(objdata['v'][vi-1] + vn + [0,0,0] + [0,0,0] + objdata['vt'][vti-1][0:2] + [0,0] + [0]))
			numverts += 1
			
outfile.write('\n}\nlocal numVerts = %d\n'%numverts)
outfile.close()
			
]]--