--Parse ASS file
package.path = package.path .. ";E:\\PROJEKTE\\FLuaG\\examples\\advanced\\karaoke\\?.lua"
require("assparser")("[Hatsune Miku] Monster universe [Original PV].ass")

--Load textures
local flying_tex = glGenTextures(3)
local silhouette_tex = glGenTextures(5)
local face_tex = glGenTextures(1)
do
    local image
    for i=1, 3 do
        image = flLoadPNG("textures\\flying" .. i .. ".png")
        glBindTexture(GL_TEXTURE_2D, flying_tex[i])
        glTexParameter(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
        glTexParameter(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image.width, image.height, 0, GL_RGBA, image)
    end
    for i=1, 5 do
        image = flLoadPNG("textures\\silhouette" .. i .. ".png")
        glBindTexture(GL_TEXTURE_2D, silhouette_tex[i])
        glTexParameter(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
        glTexParameter(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image.width, image.height, 0, GL_RGBA, image)
    end
    image = flLoadPNG("textures\\face.png")
    glBindTexture(GL_TEXTURE_2D, face_tex[1])
    glTexParameter(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
    glTexParameter(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image.width, image.height, 0, GL_RGBA, image)
end

--Text drawing list
local textlist = glGenLists(1)

--Culling for performance
glEnable(GL_CULL_FACE)
glFrontFace(GL_CW)

--Light
glLightModel(GL_LIGHT_MODEL_AMBIENT, {0, 0, 0, 1})
glLight(GL_LIGHT0, GL_AMBIENT, {0, 0, 0, 1})
glLight(GL_LIGHT0, GL_DIFFUSE, {1, 1, 1, 1})
glLight(GL_LIGHT0, GL_POSITION, {VIDEO_WIDTH/2, VIDEO_HEIGHT/2, 1500, 1})
glLight(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 0.8)
glEnable(GL_LIGHT0)
glEnable(GL_COLOR_MATERIAL)
glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE)

--Clear value
glClearDepth(1)
glDepthFunc(GL_LEQUAL)

--Help functions
local function myView(width, height, near, far, zoom)
    glMultMatrix({
        2/width, 0, 0, 0,
        0, -2/height, 0, 0,
        0, 0, -2/(far-near), -1/zoom,
        -1, 1, -(far+near)/(far-near), 1
    })
end

local function text_render(text, font, text_depth)
    local text_path = font:getpath(text)
    glNormal(0, 0, 1)
    glNewList(textlist, GL_COMPILE_AND_EXECUTE)
    gluDrawPath( text_path )
    glEndList()
    for i, p in ipairs(text_path) do
        if p.type == GLU_MOVE then glBegin(GL_TRIANGLE_STRIP) end
        local nx, ny, nz
        if i == #text_path then
            nx, ny, nz = math.calcnormal(p.x, p.y, 0, p.x, p.y, -text_depth, text_path[i-1].x, text_path[i-1].y, 0)
        else
            nx, ny, nz = math.calcnormal(p.x, p.y, 0, p.x, p.y, -text_depth, text_path[i+1].x, text_path[i+1].y, 0)
        end
        glNormal(nx, ny, nz)
        --Front
        glVertex(p.x, p.y, 0)
        --Back
        glVertex(p.x, p.y, -text_depth)
        if p.type == GLU_ENDLINE then glEnd() end
    end
    glTranslate(0, 0, -text_depth)
    glNormal(0, 0, -1)
    glFrontFace(GL_CCW)
    glCallList(textlist)
    glFrontFace(GL_CW)
end












--Karaoke rendering
local function kara_render(line, fi, ms)
    --Infade
    if ms < line.start_time then
        local pct = 1 - (line.start_time - ms) / (line.infade/2)
        local x_offset = line.height*(875/580)
        glBindTexture(GL_TEXTURE_2D, silhouette_tex[ math.mod(fi, 5)+1 ])
        glEnable(GL_TEXTURE_2D)
        glColor(1, 1, 1)
        glEnable(GL_BLEND)
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
        if line.styleref.alignment > 6 then
            glPushMatrix()
            glTranslate(pct * (VIDEO_WIDTH + x_offset), 0, 0)
            glBegin(GL_QUADS)
                glTexCoord(1, 0); glVertex(-x_offset, line.top)
                glTexCoord(0, 0); glVertex(0, line.top)
                glTexCoord(0, 1); glVertex(0, line.bottom)
                glTexCoord(1, 1); glVertex(-x_offset, line.bottom)
            glEnd()
            glPopMatrix()
        elseif line.styleref.alignment < 4 then
            glPushMatrix()
            glTranslate((1-pct) * (VIDEO_WIDTH + x_offset), 0, 0)
            glBegin(GL_QUADS)
                glTexCoord(0, 0); glVertex(-x_offset, line.top)
                glTexCoord(1, 0); glVertex(0, line.top)
                glTexCoord(1, 1); glVertex(0, line.bottom)
                glTexCoord(0, 1); glVertex(-x_offset, line.bottom)
            glEnd()
            glPopMatrix()
        end
        glDisable(GL_BLEND)
        glDisable(GL_TEXTURE_2D)
    --Outfade
    elseif ms > line.end_time then
        local pct = 1 - (line.end_time + line.outfade/2 - ms) / (line.outfade/2)
        local x_offset = line.height*1.3
        glBindTexture(GL_TEXTURE_2D, flying_tex[ math.mod(fi, 3)+1 ])
        glEnable(GL_TEXTURE_2D)
        glColor(1, 1, 1)
        glEnable(GL_BLEND)
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
        if line.styleref.alignment > 6 then
            glPushMatrix()
            glTranslate(pct * (VIDEO_WIDTH + x_offset), -(line.top + line.height) * (1 - pct ^ 0.25), 0)
            glBegin(GL_QUADS)
                glTexCoord(0, 0); glVertex(-x_offset, line.top)
                glTexCoord(1, 0); glVertex(0, line.top)
                glTexCoord(1, 1); glVertex(0, line.bottom)
                glTexCoord(0, 1); glVertex(-x_offset, line.bottom)
            glEnd()
            glPopMatrix()
        elseif line.styleref.alignment < 4 then
            glPushMatrix()
            glTranslate((1-pct) * (VIDEO_WIDTH + x_offset), (VIDEO_HEIGHT-line.top) * (1 - pct ^ 0.25), 0)
            glBegin(GL_QUADS)
                glTexCoord(1, 0); glVertex(-x_offset, line.top)
                glTexCoord(0, 0); glVertex(0, line.top)
                glTexCoord(0, 1); glVertex(0, line.bottom)
                glTexCoord(1, 1); glVertex(-x_offset, line.bottom)
            glEnd()
            glPopMatrix()
        end
        glDisable(GL_BLEND)
        glDisable(GL_TEXTURE_2D)
    --Base
    else
        for si, syl in ipairs(line.syls) do
            --Text properties
            glEnable(GL_LIGHTING)
            glColor(1, 1, 1)
            glPushMatrix()
            glTranslate(syl.x, line.y, 0)
            --Effect
            if ms >= line.start_time + syl.start_time and ms < line.start_time + syl.end_time then
                local pct = (ms-syl.start_time-line.start_time)/syl.duration
                glColor(1, 0, 0)
                glTranslate(syl.width/2, syl.height/2, -10)
                glRotate(math.random(-5,5), 1, 0, 0)
                glRotate(math.random(-5,5), 0, 1, 0)
                glTranslate(-syl.width/2, -syl.height/2, 10)
            end
            --Text drawing
            text_render(syl.text, line.styleref.font, 20)
            glPopMatrix()
            glDisable(GL_LIGHTING)
        end
    end
end

--Karaoke initialization
local function karaoke(fi, ms)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    myView(VIDEO_WIDTH, VIDEO_HEIGHT, -1000, 1000, 2000)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()
    glClear(GL_DEPTH_BUFFER_BIT)
    glEnable(GL_DEPTH_TEST)
    for li, line in ipairs(lines) do
        if line.start_time - line.infade/2 <= ms and line.end_time + line.outfade/2 > ms then
            kara_render(line, fi, ms)
        end
    end
    glDisable(GL_DEPTH_TEST)
end

--Deletes original kanjis at top
local o_red, o_green, o_blue, o_height = 88/255, 98/255, 76/255, 1-2*(130/1080)
local function grey_overlay()
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()
    glColor(o_red, o_green, o_blue)
    glRect(-1, 1, 1, o_height)
end

--Main loop
function GetFrame(frame_index, frame_ms)
    LoadFrameToContext()

    grey_overlay()
    karaoke(frame_index, frame_ms)

    SaveFrameFromContext()
end