[webgl] add colored mesh demo

thi-ng · Mar 13, 2015 · 6eea3c9 · 6eea3c9
1 parent dceee9a
commit 6eea3c9
Showing 1 changed file with 53 additions and 0 deletions.
diff --git a/geom-webgl/src/demo.org b/geom-webgl/src/demo.org
@@ -6,6 +6,7 @@
      - [[#example-1-2d-polygons][Example 1: 2D polygons]]
      - [[#example-2-extruded-2d-polygons-with-blinn-phong-shading][Example 2: Extruded 2D polygons with Blinn-Phong shading]]
      - [[#example-3-morphogen--shadow-mapping][Example 3: Morphogen & shadow mapping]]
+     - [[#example-4-colored-mesh-manual-buffer-creation][Example 4: Colored mesh (manual buffer creation)]]
 
 * WebGL examples & test scenes
 
@@ -292,3 +293,55 @@ rotation / transformation).
            ;; keep animating...
            true)))))
 #+END_SRC
+
+** Example 4: Colored mesh (manual buffer creation)
+
+#+BEGIN_SRC clojure :tangle ../babel/test/thi/ng/geom/webgl/example04.cljs :noweb yes :mkdirp yes :padline no
+  (ns thi.ng.geom.webgl.example04
+    (:require
+     [thi.ng.geom.core :as g]
+     [thi.ng.geom.core.vector :as v]
+     [thi.ng.geom.core.matrix :as mat :refer [M44]]
+     [thi.ng.geom.aabb :as a]
+     [thi.ng.geom.core.utils :as gu]
+     [thi.ng.geom.webgl.core :as gl]
+     [thi.ng.geom.webgl.arrays :as arrays]
+     [thi.ng.geom.webgl.animator :as anim]
+     [thi.ng.geom.webgl.buffers :as buf]
+     [thi.ng.geom.webgl.shaders :as sh]
+     [thi.ng.geom.webgl.shaders.basic :as basic]))
+
+  (defn colored-verts
+    [faces col]
+    (let [verts (apply concat faces)]
+      [verts (repeat (count verts) col)]))
+
+  (defn flat-map
+    [f coll] (flatten (map f coll)))
+
+  (defn ^:export demo
+    []
+    (let [gl        (gl/gl-context "main")
+          view-rect (gl/get-viewport-rect gl)
+          sides     (->> (a/aabb 1) (g/center) (g/faces) (map gu/tessellate-3))
+          col-verts (map colored-verts sides [[1 0 0 1] [0 1 0 1] [0 0 1 1] [1 1 0 1] [1 0 1 1] [0 1 1 1]])
+          verts     (flat-map first col-verts)
+          cols      (flat-map second col-verts)
+          model     (-> {:attribs      {:position {:data (arrays/float32 verts) :size 3}
+                                        :color    {:data (arrays/float32 cols) :size 4}}
+                         :uniforms     {:proj     (gl/perspective 45 view-rect 0.1 100.0)
+                                        :view     (mat/look-at (v/vec3 0 0 2) (v/vec3) v/V3Y)}
+                         :mode         gl/triangles
+                         :num-vertices (/ (count verts) 3)
+                         :shader       (->> (basic/make-color-shader-spec {:use-attrib true :3d true})
+                                            (sh/make-shader-from-spec gl))}
+                        (buf/make-attribute-buffers-in-spec gl gl/static-draw))]
+      (anim/animate
+       (fn [[t frame]]
+         (gl/set-viewport gl view-rect)
+         (gl/clear-color-buffer gl 1 1 1 1)
+         (gl/enable gl gl/depth-test)
+         (buf/draw-arrays
+          gl (assoc-in model [:uniforms :model] (-> M44 (g/rotate-x t) (g/rotate-y (* t 2)))))
+         true))))
+#+END_SRC