1 files changed, 50 insertions, 0 deletions
diff --git a/res/effectlib/depthpass.glsllib b/res/effectlib/depthpass.glsllib
new file mode 100644
index 0000000..916a33c
--- /dev/null
+++ b/res/effectlib/depthpass.glsllib
@@ -0,0 +1,50 @@
+#ifndef DEPTHPASS_GLSLIB
+#define DEPTHPASS_GLSLIB 1
+
+float calculateVertexDepth( vec2 camera_properties, vec4 position )
+{
+    float camera_range = camera_properties.y - camera_properties.x;
+    return 1.0 - ((position.w - camera_properties.x) / (camera_range));
+}
+
+vec4 outputDepth( float vert_depth )
+{
+    float integer_portion = 0.0;
+
+    float temp = vert_depth * 255.0;
+#if GLSL_100
+    //modf not supported on gles2 systems.
+    integer_portion = floor( vert_depth );
+    float fraction = vert_depth - integer_portion;
+#else
+    float fraction = modf((vert_depth * 255.0), integer_portion);
+#endif
+    return vec4( integer_portion / 255.0, fraction, 0, 1.0 );
+}
+
+float getDepthValue( vec4 depth_texture_sample, vec2 camera_properties )
+{
+
+#if __VERSION__ >= 300
+    float zNear = camera_properties.x;
+    float zFar = camera_properties.y;
+    float zRange = zFar - zNear;
+    float z_b = depth_texture_sample.x;
+    float z_n = 2.0 * z_b - 1.0;
+    float z_e = 2.0 * zNear * zFar / (zFar + zNear - z_n * (zRange));
+    return 1.0 - ((z_e - camera_properties.x) / (zRange));
+#else
+    return depth_texture_sample.x + (depth_texture_sample.y / 255.0);
+#endif
+}
+
+float depthValueToLinearDistance( float depth_value, vec2 camera_properties )
+{
+    float FarClipDistance = camera_properties.y;
+    float NearClipDistance = camera_properties.x;
+    float DepthRange = FarClipDistance - NearClipDistance;
+    float linearDepth = NearClipDistance + (DepthRange * (1.0 - depth_value));
+    return linearDepth;
+}
+
+#endif