Started work on descriptor indexing example

Refs #583

data/shaders/descriptorindexing/descriptorindexing.vert

@@ -0,0 +1,26 @@
+#version 450
+
+layout (location = 0) in vec3 inPos;
+layout (location = 1) in vec2 inUV;
+layout (location = 2) in int inTextureIndex;
+
+layout (binding = 0) uniform Matrices
+{
+	mat4 projection;
+	mat4 view;
+	mat4 model;
+} matrices;
+
+layout (location = 0) out vec2 outUV;
+layout (location = 1) flat out int outTexIndex;
+
+void main() 
+{
+	outUV = inUV;
+	outTexIndex = 0;
+	outTexIndex = inTextureIndex;
+	outTexIndex = gl_InstanceIndex;
+	vec4 pos = vec4(inPos, 1.0f);
+	pos.y += gl_InstanceIndex;
+	gl_Position = matrices.projection * matrices.view * matrices.model * pos;
+}