Shading: add direction modes and phase offset to wave texture node

* Direction mode X, Y and Z to align with axes rather than diagonal or
  spherical as previously. X is the new default, existing files will
  use diagonal or spherical for compatibility.
* Phase offset to offset the wave along its direction, for purposes like
  animation and distortion.

https://developer.blender.org/D6382

1 files changed, 59 insertions, 10 deletions

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_tex_wave.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_tex_wave.glsl
index 957aa606a79..c72f9717af3 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_tex_wave.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_tex_wave.glsl
@@ -1,26 +1,64 @@
-float calc_wave(
-    vec3 p, float distortion, float detail, float detail_scale, int wave_type, int wave_profile)
+float calc_wave(vec3 p,
+                float distortion,
+                float detail,
+                float detail_scale,
+                float phase,
+                int wave_type,
+                int bands_dir,
+                int rings_dir,
+                int wave_profile)
 {
+  /* Prevent precision issues on unit coordinates. */
+  p = (p + 0.000001) * 0.999999;
+
   float n;
 
-  if (wave_type == 0) { /* type bands */
-    n = (p.x + p.y + p.z) * 10.0;
+  if (wave_type == 0) {   /* type bands */
+    if (bands_dir == 0) { /* X axis */
+      n = p.x * 20.0;
+    }
+    else if (bands_dir == 1) { /* Y axis */
+      n = p.y * 20.0;
+    }
+    else if (bands_dir == 2) { /* Z axis */
+      n = p.z * 20.0;
+    }
+    else { /* Diagonal axis */
+      n = (p.x + p.y + p.z) * 10.0;
+    }
   }
   else { /* type rings */
-    n = length(p) * 20.0;
+    vec3 rp = p;
+    if (rings_dir == 0) { /* X axis */
+      rp *= vec3(0.0, 1.0, 1.0);
+    }
+    else if (rings_dir == 1) { /* Y axis */
+      rp *= vec3(1.0, 0.0, 1.0);
+    }
+    else if (rings_dir == 2) { /* Z axis */
+      rp *= vec3(1.0, 1.0, 0.0);
+    }
+    /* else: Spherical */
+
+    n = length(rp) * 20.0;
   }
 
+  n += phase;
+
   if (distortion != 0.0) {
     n += distortion * (fractal_noise(p * detail_scale, detail) * 2.0 - 1.0);
   }
 
   if (wave_profile == 0) { /* profile sin */
-    return 0.5 + 0.5 * sin(n);
+    return 0.5 + 0.5 * sin(n - M_PI_2);
+  }
+  else if (wave_profile == 1) { /* profile saw */
+    n /= 2.0 * M_PI;
+    return n - floor(n);
   }
-  else { /* profile saw */
+  else { /* profile tri */
     n /= 2.0 * M_PI;
-    n -= int(n);
-    return (n < 0.0) ? n + 1.0 : n;
+    return abs(n - floor(n + 0.5)) * 2.0;
   }
 }
 
@@ -29,13 +67,24 @@ void node_tex_wave(vec3 co,
                    float distortion,
                    float detail,
                    float detail_scale,
+                   float phase,
                    float wave_type,
+                   float bands_dir,
+                   float rings_dir,
                    float wave_profile,
                    out vec4 color,
                    out float fac)
 {
   float f;
-  f = calc_wave(co * scale, distortion, detail, detail_scale, int(wave_type), int(wave_profile));
+  f = calc_wave(co * scale,
+                distortion,
+                detail,
+                detail_scale,
+                phase,
+                int(wave_type),
+                int(bands_dir),
+                int(rings_dir),
+                int(wave_profile));
 
   color = vec4(f, f, f, 1.0);
   fac = f;