Curve: CurveMapping Extend Option

Extend options are currently stored per curve. This was not clearly
communicated to the user and they expected this to be a setting per
CurveMapping.

This change will move the option from `Curve` to `CurveMapping`. In
order to support this the API had to be changed.

BPY: CurveMap.evaluate is also moved to CurveMapping.evaluate what
breaks Python API. Cycles has been updated but other add-ons have
not. After release of 2.81 we can merge this to master and adapt
the add-ons.

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D6169

intern/cycles/blender/blender_util.h

@@ -159,7 +159,7 @@ static inline void curvemapping_to_array(BL::CurveMapping &cumap, array<float> &
   data.resize(size);
   for (int i = 0; i < size; i++) {
     float t = (float)i / (float)(size - 1);
-    data[i] = curve.evaluate(t);
+    data[i] = cumap.evaluate(curve, t);
   }
 }
 
@@ -197,15 +197,16 @@ static inline void curvemapping_color_to_array(BL::CurveMapping &cumap,
     BL::CurveMap mapI = cumap.curves[3];
     for (int i = 0; i < size; i++) {
       const float t = min_x + (float)i / (float)(size - 1) * range_x;
-      data[i] = make_float3(mapR.evaluate(mapI.evaluate(t)),
-                            mapG.evaluate(mapI.evaluate(t)),
-                            mapB.evaluate(mapI.evaluate(t)));
+      data[i] = make_float3(cumap.evaluate(mapR, cumap.evaluate(mapI, t)),
+                            cumap.evaluate(mapG, cumap.evaluate(mapI, t)),
+                            cumap.evaluate(mapB, cumap.evaluate(mapI, t)));
     }
   }
   else {
     for (int i = 0; i < size; i++) {
       float t = min_x + (float)i / (float)(size - 1) * range_x;
-      data[i] = make_float3(mapR.evaluate(t), mapG.evaluate(t), mapB.evaluate(t));
+      data[i] = make_float3(
+          cumap.evaluate(mapR, t), cumap.evaluate(mapG, t), cumap.evaluate(mapB, t));
     }
   }
 }

intern/opencolorio/gpu_shader_display_transform.glsl

@@ -16,7 +16,7 @@ out vec4 fragColor;
  */
 uniform sampler1D curve_mapping_texture;
 uniform int curve_mapping_lut_size;
-uniform ivec4 use_curve_mapping_extend_extrapolate;
+uniform int use_curve_mapping_extend_extrapolate;
 uniform vec4 curve_mapping_mintable;
 uniform vec4 curve_mapping_range;
 uniform vec4 curve_mapping_ext_in_x;
@@ -42,8 +42,8 @@ float read_curve_mapping(int table, int index)
 float curvemap_calc_extend(int table, float x, vec2 first, vec2 last)
 {
   if (x <= first[0]) {
-    if (use_curve_mapping_extend_extrapolate[table] == 0) {
-      /* no extrapolate */
+    if (use_curve_mapping_extend_extrapolate == 0) {
+      /* horizontal extrapolation */
       return first[1];
     }
     else {
@@ -55,8 +55,8 @@ float curvemap_calc_extend(int table, float x, vec2 first, vec2 last)
     }
   }
   else if (x >= last[0]) {
-    if (use_curve_mapping_extend_extrapolate[table] == 0) {
-      /* no extrapolate */
+    if (use_curve_mapping_extend_extrapolate == 0) {
+      /* horizontal extrapolation */
       return last[1];
     }
     else {

intern/opencolorio/ocio_capi.h

@@ -73,10 +73,10 @@ typedef struct OCIO_CurveMappingSettings {
   int lut_size;
 
   /* Extend extrapolation flags for all the tables.
-   * if use_extend_extrapolate[T] != 0 means extrapolation for
-   * table T is needed.
+   * if use_extend_extrapolate != 0 means extrapolation for
+   * curve.
    */
-  int use_extend_extrapolate[4];
+  int use_extend_extrapolate;
 
   /* Minimal X value of the curve mapping tables. */
   float mintable[4];

intern/opencolorio/ocio_impl_glsl.cc

@@ -499,8 +499,8 @@ bool OCIOImpl::setupGLSLDraw(OCIO_GLSLDrawState **state_r,
     if (use_curve_mapping) {
       immUniform1i("curve_mapping_texture", 2);
       immUniform1i("curve_mapping_lut_size", curve_mapping_settings->lut_size);
-      immUniform4iv("use_curve_mapping_extend_extrapolate",
-                    curve_mapping_settings->use_extend_extrapolate);
+      immUniform1i("use_curve_mapping_extend_extrapolate",
+                   curve_mapping_settings->use_extend_extrapolate);
       immUniform4fv("curve_mapping_mintable", curve_mapping_settings->mintable);
       immUniform4fv("curve_mapping_range", curve_mapping_settings->range);
       immUniform4fv("curve_mapping_ext_in_x", curve_mapping_settings->ext_in_x);