Actual blob shading yaaay

res/shader/blob.frag

@@ -1,5 +1,21 @@
-void main()
-{
-    // Setting Each Pixel To Red
-    gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0);
+varying vec2 xy;
+uniform vec4 blobs[10];
+
+float doBlob(vec4 blob) {
+  vec2 s = pow(blob.xy - xy, vec2(2.0, 2.0));
+  return 1.0 / ((s.x / blob.z) + (s.y / blob.w));
+}
+void main() {
+  float v = 0.0;
+  for (int i = 0; i < 10; i ++) {
+    v += doBlob(blobs[i]/*vec4(0.3, 0.3, 0.1, 0.1)*/);
+  }
+  float celledge = min(fract(xy.x), fract(xy.y));
+  float majorxy = (fract(xy.x) < fract(xy.y)) ? xy.x : xy.y;
+  float cell = (mod(abs(floor(majorxy)), 2.0) + 1.0) / 2.0;
+  
+  gl_FragColor = v > 0.32        ? vec4(1.0, 1.0, 1.0, 1.0) :
+                (v > 0.3         ? vec4(v, v, v, 1.0) :
+                (celledge < 0.01 ? vec4(cell, cell, cell, 1.0)
+                                 : vec4(0.0, 0.0, 0.0, 0.0)));
 }

res/shader/blob.vert

@@ -1,5 +1,6 @@
-void main()
-{
-    // Transforming The Vertex
+varying vec2 xy;
+
+void main() {
     gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
+    xy = vec2(gl_MultiTexCoord0);
 }

src/celldiv/blob.clj

@@ -0,0 +1,38 @@
+(ns celldiv.blob
+  (:import [org.newdawn.slick.opengl.renderer Renderer SGL]
+           [org.lwjgl BufferUtils]
+           [org.lwjgl.opengl ARBShaderObjects])
+  (:require [hottub.resource :as res]))
+
+(def minx -3)
+(def maxx 3)
+(def miny -3)
+(def maxy 3)
+(def GL (Renderer/get))
+(def blobbuf (BufferUtils/createFloatBuffer (* 4 10)))
+(def emptyblob {:x 0 :y 0 :scalex 0 :scaley 0})
+
+(defn with-blob-shader [f & args]
+  (let [shader (res/get-shader "res/shader/blob")]
+    (.bind shader)
+    (apply f shader args)
+    (.unbind shader)))
+
+(defn draw-blobs [shader blobs x y w h]
+  (.glBegin GL SGL/GL_QUADS)
+    (let [blobs (take 10 (concat blobs (cycle [emptyblob])))
+          floats (flatten (map (fn [{:keys [x y scalex scaley]}] [x y scalex scaley]) blobs))]
+      (.rewind blobbuf)
+      (doseq [v floats] (.put blobbuf (float v)))
+      (.rewind blobbuf)
+      (ARBShaderObjects/glUniform4ARB (.getUniformID shader "blobs") blobbuf))
+    (.glTexCoord2f GL minx miny)
+    (.glVertex3f GL x y 0)
+    (.glTexCoord2f GL minx maxy)
+    (.glVertex3f GL x (+ y h) 0)
+    (.glTexCoord2f GL maxx maxy)
+    (.glVertex3f GL (+ x w) (+ y h) 0)
+    (.glTexCoord2f GL maxx miny)
+    (.glVertex3f GL (+ x w) y 0)
+  (.glEnd GL))
+

src/hottub/core.clj

@@ -4,7 +4,8 @@
             [hottub.resource :as res]
             [hottub.timeline :as tln]
             [hottub.screen :as scr]
-            [hottub.util :as u]))
+            [hottub.util :as u]
+            [celldiv.blob :as blob]))
 
 (defn -main [& args]
   (res/start-resource-expiry-thread)
@@ -41,13 +42,12 @@
 
 (defn render-gs [gs g]
   (gs/with-gs gs
-    (let [shader (res/get-shader "res/shader/blob")]
-      (.bind shader)
-      (.fillRect g 0 0 100 100)
-      (.unbind shader))
     (doseq [sprite (gs/q :type :sprite)]
       (if-let [image (res/get-image (:image sprite))]
-        (.draw image (:x sprite) (:y sprite))))))
+        (.draw image (:x sprite) (:y sprite))))
+    (blob/with-blob-shader blob/draw-blobs 
+                           [{:x 0.3 :y 0.4 :scalex 0.2 :scaley 0.3}
+                            {:x -0.3 :y -0.4 :scalex 0.5 :scaley 0.3}] 0 0 300 300)))
 
 (defmethod slick/update-game :game [screen inputtln delta]
   (if-let [input (tln/timeline-last-value inputtln)]
@@ -89,7 +89,7 @@
         tln (:tln subscreen)
         ts (tln/time-nearest tln (:ts screen))
         gs (last (get tln ts))]
-    (render-gs gs)))
+    (render-gs gs graphics)))
 
 ;;; repl helpers
 (def ^:dynamic g nil)