In the variational refinement, change the flow unit from normalized coordinates to...

[nageru] / equations.frag

diff --git a/equations.frag b/equations.frag
index 3926351a600a75bc43aad89335dcdf0e23575ebf..6171a3729d6f862490e288e5125152227d6756b1 100644 (file)
--- a/equations.frag
+++ b/equations.frag
@@ -11,24 +11,16 @@ uniform sampler2D smoothness_x_tex, smoothness_y_tex;
 // TODO: Consider a specialized version for the case where we know that du = dv = 0,
 // since we run so few iterations.
 
-// The base flow needs to be normalized.
-// TODO: Should we perhaps reduce this to a separate two-component
-// texture when calculating the derivatives?
-vec2 normalize_flow(vec3 flow)
-{
-       return flow.xy / flow.z;
-}
-
 // This must be a macro, since the offset needs to be a constant expression.
 #define get_flow(x_offs, y_offs) \
-       (normalize_flow(textureOffset(flow_tex, tc, ivec2((x_offs), (y_offs))).xyz) + \
+       (textureOffset(flow_tex, tc, ivec2((x_offs), (y_offs))).xy + \
        textureOffset(diff_flow_tex, tc, ivec2((x_offs), (y_offs))).xy)
 
 void main()
 {
        // Read the flow (on top of the u0/v0 flow).
        vec2 diff_flow = texture(diff_flow_tex, tc).xy;
-       float du = diff_flow.x;  // FIXME: convert to pixels?
+       float du = diff_flow.x;
        float dv = diff_flow.y;
 
        // Read the first derivatives.
@@ -115,7 +107,7 @@ void main()
 
        // The central term of the Laplacian, for (u0, v0) only.
        // (The central term for (du, dv) is what we are solving for.)
-       vec2 central = (smooth_l + smooth_r + smooth_d + smooth_u) * normalize_flow(texture(flow_tex, tc).xyz);
+       vec2 central = (smooth_l + smooth_r + smooth_d + smooth_u) * texture(flow_tex, tc).xy;
        b1 += central.x;
        b2 += central.y;