1 files changed, 123 insertions, 0 deletions
diff --git a/intern/opencolorio/gpu_shader_display_transform.glsl b/intern/opencolorio/gpu_shader_display_transform.glsl
new file mode 100644
index 00000000000..6ba3fa55e8f
--- /dev/null
+++ b/intern/opencolorio/gpu_shader_display_transform.glsl
@@ -0,0 +1,123 @@
+uniform sampler2D image_texture;
+uniform sampler3D lut3d_texture;
+uniform bool predivide;
+
+#ifdef USE_CURVE_MAPPING
+/* Curve mapping parameters
+ *
+ * See documentation for OCIO_CurveMappingSettings to get fields descriptions.
+ * (this ones pretyt much copies stuff from C structure.)
+ */
+uniform sampler1D curve_mapping_texture;
+uniform int curve_mapping_lut_size;
+uniform ivec4 use_curve_mapping_extend_extrapolate;
+uniform vec4 curve_mapping_mintable;
+uniform vec4 curve_mapping_range;
+uniform vec4 curve_mapping_ext_in_x;
+uniform vec4 curve_mapping_ext_in_y;
+uniform vec4 curve_mapping_ext_out_x;
+uniform vec4 curve_mapping_ext_out_y;
+uniform vec4 curve_mapping_first_x;
+uniform vec4 curve_mapping_first_y;
+uniform vec4 curve_mapping_last_x;
+uniform vec4 curve_mapping_last_y;
+uniform vec3 curve_mapping_black;
+uniform vec3 curve_mapping_bwmul;
+
+float read_curve_mapping(int table, int index)
+{
+	/* TODO(sergey): Without -1 here image is getting darken after applying unite curve.
+	 *               But is it actually correct to subtract 1 here?
+	 */
+	float texture_index = float(index) / float(curve_mapping_lut_size  - 1);
+	return texture1D(curve_mapping_texture, texture_index) [table];
+}
+
+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 */
+			return first[1];
+		}
+		else {
+			if (curve_mapping_ext_in_x[table] == 0.0)
+				return first[1] + curve_mapping_ext_in_y[table] * 10000.0;
+			else
+				return first[1] + curve_mapping_ext_in_y[table] * (x - first[0]) / curve_mapping_ext_in_x[table];
+		}
+	}
+	else if (x >= last[0]) {
+		if (use_curve_mapping_extend_extrapolate[table] == 0) {
+			/* no extrapolate */
+			return last[1];
+		}
+		else {
+			if (curve_mapping_ext_out_x[table] == 0.0)
+				return last[1] - curve_mapping_ext_out_y[table] * 10000.0;
+			else
+				return last[1] + curve_mapping_ext_out_y[table] * (x - last[0]) / curve_mapping_ext_out_x[table];
+		}
+	}
+	return 0.0;
+}
+
+float curvemap_evaluateF(int table, float value)
+{
+	float mintable_ = curve_mapping_mintable[table];
+	float range = curve_mapping_range[table];
+	float mintable = 0.0;
+	int CM_TABLE = curve_mapping_lut_size - 1;
+
+	float fi;
+	int i;
+
+	/* index in table */
+	fi = (value - mintable) * range;
+	i = int(fi);
+
+	/* fi is table float index and should check against table range i.e. [0.0 CM_TABLE] */
+	if (fi < 0.0 || fi > float(CM_TABLE)) {
+		return curvemap_calc_extend(table, value,
+		                            vec2(curve_mapping_first_x[table], curve_mapping_first_y[table]),
+		                            vec2(curve_mapping_last_x[table], curve_mapping_last_y[table]));
+	}
+	else {
+		if (i < 0) return read_curve_mapping(table, 0);
+		if (i >= CM_TABLE) return read_curve_mapping(table, CM_TABLE);
+
+		fi = fi - float(i);
+		return (1.0 - fi) * read_curve_mapping(table, i) + fi * read_curve_mapping(table, i + 1);
+	}
+}
+
+vec4 curvemapping_evaluate_premulRGBF(vec4 col)
+{
+	vec4 result = col;
+	result[0] = curvemap_evaluateF(0, (col[0] - curve_mapping_black[0]) * curve_mapping_bwmul[0]);
+	result[1] = curvemap_evaluateF(1, (col[1] - curve_mapping_black[1]) * curve_mapping_bwmul[1]);
+	result[2] = curvemap_evaluateF(2, (col[2] - curve_mapping_black[2]) * curve_mapping_bwmul[2]);
+	result[3] = col[3];
+	return result;
+}
+#endif
+
+void main()
+{
+	vec4 col = texture2D(image_texture, gl_TexCoord[0].st);
+#ifdef USE_CURVE_MAPPING
+	col = curvemapping_evaluate_premulRGBF(col);
+#endif
+	if (predivide && col[3] > 0.0 && col[3] < 1.0) {
+		float inv_alpha = 1.0 / col[3];
+		col[0] *= inv_alpha;
+		col[1] *= inv_alpha;
+		col[2] *= inv_alpha;
+	}
+
+	/* NOTE: This is true we only do de-premul here and NO premul
+	 *       and the reason is simple -- opengl is always configured
+	 *       for straight alpha at this moment
+	 */
+	gl_FragColor = OCIODisplay(col, lut3d_texture);
+}