scratch.cljs

(ns c.g.scratch
  (:require-macros [cljs.core.async.macros :refer [go go-loop]]
                   [c.u.q :refer [defq qi qn]])
  (:require [clojure.string]
            [oops.core :refer [ocall oget oset!]]
            [cljs.core.async :as a]
            [c.g.shader]
            [c.u.spec]
            [cljsjs.opentype]
            [dirac.runtime]
            [devtools.core]))


(dirac.runtime/install!)
(devtools.core/install!)


(let [v2 (qn :vec2 20 20)
      d2 (qn :dim2 23 58)
      bb (qn :bbox v2 d2)
      x (qi bb [:bbox/vec2])])


(def vertex-source
  (clojure.string/join
   "\n"
   ["#version 300 es"
    "#define POSITION_LOCATION 0"
    "precision highp float;"
    "precision highp int;"
    "layout(location = POSITION_LOCATION) in vec2 position;"
    "void main() {"
    "  gl_Position = vec4(position, 0.0, 1.0);"
    "}"]))

(def fragment-source
  (clojure.string/join
   "\n"
   [
    "#version 300 es"
    "precision highp float;"
    "precision highp int;" 
    "uniform sampler2D diffuse;"
    "uniform vec2 u_imageSize;"
    "out vec4 color;"

    "void main() {"
    "  color = vec4(1, 0, 1, 0.5);"
    "}"]))

;//texture(diffuse, vec2(gl_FragCoord.x, 1.0 - gl_FragCoord.y) / u_imageSize);

;; (def font-chan (a/chan))

;; 
;; (defn load-opentype [fname c]
;;   (js/opentype.load
;;    fname
;;    (fn [err font]
;;      (if err
;;        (go (a/>! c [:err err]))
;;        (go (a/>! c [:font font]))
;;        ;; (op-on-font font)
;;        ) )))


;; (load-opentype "kafonts/KaTeX_Typewriter-Regular.ttf" font-chan)



(defn gen-canvas [;; font
                  ]
  (let [;; glyphs (js->clj (oget font "glyphs.glyphs"))
        canvas (ocall js/document "createElement" "canvas")
        _ (oset! canvas "width" 1024)
        _ (oset! canvas "height" 1024)
        ctx (ocall canvas "getContext" "2d")]
    ;; (doseq [[i [asc glyph]] (keep-indexed vector (sort glyphs ))
    ;;         :let [y (quot i 32)
    ;;               x (rem i 32)]]
    ;;   (ocall glyph "draw" ctx (* x 64) (* y 128) 64))
    canvas))


(defn run []
  (go
    (let [;; [t font] (a/<! font-chan)
          canvas (ocall js/document "getElementById" "c")
          _ (oset! canvas "width" 2048)
          _ (oset! canvas "height" 2048)
          
          gl (ocall canvas "getContext" "webgl2")
          _ (assert gl)

          vertex-shader (c.g.shader/create-shader gl (.-VERTEX_SHADER gl) vertex-source)
          fragment-shader (c.g.shader/create-shader gl (.-FRAGMENT_SHADER gl) fragment-source)
          program (c.g.shader/create-program gl vertex-shader fragment-shader)
          diffuse-location (ocall gl "getUniformLocation" program "diffuse")
          image-size-location (ocall gl "getUniformLocation" program "u_imageSize")


          vertex-pos-buffer (ocall gl "createBuffer")
          _ (ocall gl "bindBuffer" (oget gl  "ARRAY_BUFFER") vertex-pos-buffer)
          vertex-count 12
          vertices (js/Float32Array.
                    (clj->js
                     [-0.8, -0.8,
                      0.8, -0.8,
                      0.8,  0.8,
                      0.8,  0.8,
                      -0.8, 0.8,
                      -0.8, -0.8,
                      -0.5, -0.5,
                      0.5, -0.5,
                      0.5, 0.5,
                      0.5, 0.5,
                      -0.5, 0.5,
                      -0.5, -0.5,]))
          _ (ocall gl "bufferData"
                   (oget gl "ARRAY_BUFFER")
                   vertices
                   (oget gl "STATIC_DRAW"))
          
          vertex-array (ocall gl "createVertexArray")
          _ (ocall gl "bindVertexArray" vertex-array)]
      (ocall gl "bindVertexArray" vertex-array)
      (ocall gl "bindVertexArray" nil)

      


      (let [texture (ocall gl "createTexture")
            canvas (gen-canvas ;; font
                    )
            vertex-pos-location 0]
        
        
        
        (ocall gl "activeTexture" (oget gl "TEXTURE0"))
        (ocall gl "bindTexture" (oget gl "TEXTURE_2D") texture)
        (ocall gl "pixelStorei" (oget gl "UNPACK_FLIP_Y_WEBGL") false)
        (ocall gl "texImage2D" (oget gl "TEXTURE_2D") 0 (oget gl "RGBA") (oget gl "RGBA") (oget gl "UNSIGNED_BYTE") canvas)
        (ocall gl "texParameteri" (oget gl "TEXTURE_2D") (oget gl "TEXTURE_MAG_FILTER") (oget gl "LINEAR"))
        (ocall gl "texParameteri" (oget gl "TEXTURE_2D") (oget gl "TEXTURE_MIN_FILTER") (oget gl "LINEAR"))


        
        (ocall gl "clearColor" 0 0 0 1)
        (ocall gl "clear" (oget gl "COLOR_BUFFER_BIT"))

        
        (ocall gl "useProgram" program)
        (ocall gl "uniform1i" diffuse-location 0)
        (ocall gl "uniform2f" image-size-location 1024 1024)

        

        (ocall gl "enableVertexAttribArray" vertex-pos-location)
        (ocall gl "vertexAttribPointer" vertex-pos-location 2 (oget gl "FLOAT") false 0 0)
        (ocall gl "bindVertexArray" nil )
        (ocall gl "bindVertexArray" vertex-array)

        (ocall gl "bindVertexArray" vertex-array)
        
        (ocall gl "drawArrays" (oget gl "TRIANGLES") 0 (/ vertex-count 2))


        (ocall gl "deleteTexture" texture)
        (ocall gl "deleteProgram" program)
        (ocall gl "deleteVertexArray" vertex-array)))))