Fix T67552 EEVEE: Vector Curves node clamps maximum input value at 1.0

1 files changed, 35 insertions, 2 deletions

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_vector_curves.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_vector_curves.glsl
index 35d2e903cf4..63e97e66c90 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_vector_curves.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_vector_curves.glsl
@@ -1,8 +1,41 @@
-void curves_vec(float fac, vec3 vec, sampler1DArray curvemap, float layer, out vec3 outvec)
+/* ext is vec4(in_x, in_dy, out_x, out_dy). */
+float curve_extrapolate(float x, float y, vec4 ext)
 {
-  vec4 co = vec4(vec * 0.5 + 0.5, layer);
+  if (x < 0.0) {
+    return y + x * ext.y;
+  }
+  else if (x > 1.0) {
+    return y + (x - 1.0) * ext.w;
+  }
+  else {
+    return y;
+  }
+}
+
+#define RANGE_RESCALE(x, min, range) ((x - min) * range)
+
+void curves_vec(float fac,
+                vec3 vec,
+                sampler1DArray curvemap,
+                float layer,
+                vec3 range,
+                vec4 ext_x,
+                vec4 ext_y,
+                vec4 ext_z,
+                out vec3 outvec)
+{
+  vec4 co = vec4(vec, layer);
+
+  vec3 xyz_min = vec3(ext_x.x, ext_y.x, ext_z.x);
+  co.xyz = RANGE_RESCALE(co.xyz, xyz_min, range);
+
   outvec.x = texture(curvemap, co.xw).x;
   outvec.y = texture(curvemap, co.yw).y;
   outvec.z = texture(curvemap, co.zw).z;
+
+  outvec.x = curve_extrapolate(co.x, outvec.r, ext_x);
+  outvec.y = curve_extrapolate(co.y, outvec.g, ext_y);
+  outvec.z = curve_extrapolate(co.z, outvec.b, ext_z);
+
   outvec = mix(vec, outvec, fac);
 }