Pass depth range to depth map visualization shader

Fixes #895

data/shaders/glsl/shadowmapping/quad.frag

@@ -6,10 +6,21 @@ layout (location = 0) in vec2 inUV;
 
 layout (location = 0) out vec4 outFragColor;
 
+layout (binding = 0) uniform UBO 
+{
+	mat4 projection;
+	mat4 view;
+	mat4 model;
+	mat4 lightSpace;
+	vec4 lightPos;
+	float zNear;
+	float zFar;
+} ubo;
+
 float LinearizeDepth(float depth)
 {
-  float n = 1.0; // camera z near
-  float f = 128.0; // camera z far
+  float n = ubo.zNear;
+  float f = ubo.zFar;
   float z = depth;
   return (2.0 * n) / (f + n - z * (f - n));	
 }

data/shaders/glsl/shadowmapping/scene.vert

@@ -11,7 +11,9 @@ layout (binding = 0) uniform UBO
 	mat4 view;
 	mat4 model;
 	mat4 lightSpace;
-	vec3 lightPos;
+	vec4 lightPos;
+	float zNear;
+	float zFar;
 } ubo;
 
 layout (location = 0) out vec3 outNormal;
@@ -20,11 +22,6 @@ layout (location = 2) out vec3 outViewVec;
 layout (location = 3) out vec3 outLightVec;
 layout (location = 4) out vec4 outShadowCoord;
 
-out gl_PerVertex 
-{
-    vec4 gl_Position;   
-};
-
 const mat4 biasMat = mat4( 
 	0.5, 0.0, 0.0, 0.0,
 	0.0, 0.5, 0.0, 0.0,
@@ -40,7 +37,7 @@ void main()
 	
     vec4 pos = ubo.model * vec4(inPos, 1.0);
     outNormal = mat3(ubo.model) * inNormal;
-    outLightVec = normalize(ubo.lightPos - inPos);
+    outLightVec = normalize(ubo.lightPos.xyz - inPos);
     outViewVec = -pos.xyz;			
 
 	outShadowCoord = ( biasMat * ubo.lightSpace * ubo.model ) * vec4(inPos, 1.0);