Nodes: Add Float Curve for GN and Shader nodes.

Replacement for float curve in legacy Attribute Curve Map node.

Float Curve defaults to [0.0-1.0] range.

Reviewed By: JacquesLucke, brecht

Differential Revision: https://developer.blender.org/D12683

3 files changed, 41 insertions, 0 deletions

diff --git a/source/blender/gpu/CMakeLists.txt b/source/blender/gpu/CMakeLists.txt
index df370c7079b..7a072900473 100644
--- a/source/blender/gpu/CMakeLists.txt
+++ b/source/blender/gpu/CMakeLists.txt
@@ -296,6 +296,7 @@ data_to_c_simple(shaders/material/gpu_shader_material_diffuse.glsl SRC)
 data_to_c_simple(shaders/material/gpu_shader_material_displacement.glsl SRC)
 data_to_c_simple(shaders/material/gpu_shader_material_eevee_specular.glsl SRC)
 data_to_c_simple(shaders/material/gpu_shader_material_emission.glsl SRC)
+data_to_c_simple(shaders/material/gpu_shader_material_float_curve.glsl SRC)
 data_to_c_simple(shaders/material/gpu_shader_material_fractal_noise.glsl SRC)
 data_to_c_simple(shaders/material/gpu_shader_material_fresnel.glsl SRC)
 data_to_c_simple(shaders/material/gpu_shader_material_gamma.glsl SRC)
diff --git a/source/blender/gpu/intern/gpu_material_library.c b/source/blender/gpu/intern/gpu_material_library.c
index 73a80c62bdc..74e0270c42a 100644
--- a/source/blender/gpu/intern/gpu_material_library.c
+++ b/source/blender/gpu/intern/gpu_material_library.c
@@ -62,6 +62,7 @@ extern char datatoc_gpu_shader_material_diffuse_glsl[];
 extern char datatoc_gpu_shader_material_displacement_glsl[];
 extern char datatoc_gpu_shader_material_eevee_specular_glsl[];
 extern char datatoc_gpu_shader_material_emission_glsl[];
+extern char datatoc_gpu_shader_material_float_curve_glsl[];
 extern char datatoc_gpu_shader_material_fractal_noise_glsl[];
 extern char datatoc_gpu_shader_material_fresnel_glsl[];
 extern char datatoc_gpu_shader_material_gamma_glsl[];
@@ -262,6 +263,11 @@ static GPUMaterialLibrary gpu_shader_material_emission_library = {
     .dependencies = {NULL},
 };
 
+static GPUMaterialLibrary gpu_shader_material_float_curve_library = {
+    .code = datatoc_gpu_shader_material_float_curve_glsl,
+    .dependencies = {NULL},
+};
+
 static GPUMaterialLibrary gpu_shader_material_fresnel_library = {
     .code = datatoc_gpu_shader_material_fresnel_glsl,
     .dependencies = {NULL},
@@ -591,6 +597,7 @@ static GPUMaterialLibrary *gpu_material_libraries[] = {
     &gpu_shader_material_color_util_library,
     &gpu_shader_material_hash_library,
     &gpu_shader_material_noise_library,
+    &gpu_shader_material_float_curve_library,
     &gpu_shader_material_fractal_noise_library,
     &gpu_shader_material_add_shader_library,
     &gpu_shader_material_ambient_occlusion_library,
diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_float_curve.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_float_curve.glsl
new file mode 100644
index 00000000000..514409f7fdf
--- /dev/null
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_float_curve.glsl
@@ -0,0 +1,33 @@
+/* ext is vec4(in_x, in_dy, out_x, out_dy). */
+float curve_float_extrapolate(float x, float y, vec4 ext)
+{
+  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 curve_float(float fac,
+                 float vec,
+                 sampler1DArray curvemap,
+                 float layer,
+                 float range,
+                 vec4 ext,
+                 out float outvec)
+{
+  float xyz_min = ext.x;
+  vec = RANGE_RESCALE(vec, xyz_min, range);
+
+  outvec = texture(curvemap, vec2(vec, layer)).x;
+
+  outvec = curve_float_extrapolate(vec, outvec, ext);
+
+  outvec = mix(vec, outvec, fac);
+}