Use texture to draw points with WebGL

src/ol/renderer/webgl/webglvectorlayer.glsl

@@ -3,20 +3,26 @@
 
 
 //! COMMON
+varying vec2 v_texCoord;
 
 //! VERTEX
 attribute vec2 a_position;
+attribute vec2 a_texCoord;
 attribute vec2 a_offsets;
 
 uniform mat4 u_projectionMatrix;
+uniform mat2 u_sizeMatrix;
 
 void main(void) {
-  gl_Position = u_projectionMatrix * vec4(a_position, 0., 1.) + vec4(a_offsets, 0., 0.);
+  vec2 offsets = u_sizeMatrix * a_offsets;
+  gl_Position = u_projectionMatrix * vec4(a_position, 0., 1.) + vec4(offsets, 0., 0.);
+  v_texCoord = a_texCoord;
 }
 
 
 //! FRAGMENT
+uniform sampler2D u_image;
 
 void main(void) {
-  gl_FragColor = vec4(1.0, 1.0, 0.0, 1);
+  gl_FragColor = texture2D(u_image, v_texCoord);
 }