Elements: ColorCorrectionMatrix: initial implementation

Color Correction Matrix (CCM) is a GL filter that makes basic color correction

Signed-off-by: Vasiliy Doylov <nekocwd@mainlining.org>

src/elements/color_correction_matrix.vala

@@ -0,0 +1,59 @@
+/* color_correction_matrix.vala
+ *
+ * Copyright 2025 Vasiliy Doylov <nekocwd@mainlining.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+public class EyeNeko.Elements.ColorCorrectionMatrix : GLFilter {
+    public float red_in_red { get; set; default = 1.0f; }
+    public float red_in_green { get; set; default = 0.0f; }
+    public float red_in_blue { get; set; default = 0.0f; }
+
+    public float green_in_red { get; set; default = 0.0f; }
+    public float green_in_green { get; set; default = 1.0f; }
+    public float green_in_blue { get; set; default = 0.0f; }
+
+    public float blue_in_red { get; set; default = 0.0f; }
+    public float blue_in_green { get; set; default = 0.0f; }
+    public float blue_in_blue { get; set; default = 1.0f; }
+
+    static construct {
+        set_static_metadata("colorcorrectionmatrix",
+                            "Filter",
+                            "Color correction matrix video filter.",
+                            "nekocwd@mainlining.org");
+    }
+
+    construct {
+        set_shader("ccm");
+    }
+
+    protected override void update_uniforms() {
+        Gst.Structure uniforms = new Gst.Structure.empty("uniforms");
+        uniforms.set("rr", typeof (float), red_in_red);
+        uniforms.set("rg", typeof (float), red_in_green);
+        uniforms.set("rb", typeof (float), red_in_blue);
+        uniforms.set("gr", typeof (float), green_in_red);
+        uniforms.set("gg", typeof (float), green_in_green);
+        uniforms.set("gb", typeof (float), green_in_blue);
+        uniforms.set("br", typeof (float), blue_in_red);
+        uniforms.set("bg", typeof (float), blue_in_green);
+        uniforms.set("bb", typeof (float), blue_in_blue);
+
+        glshader.set_property("uniforms", uniforms);
+    }
+}

src/meson.build

@@ -13,6 +13,7 @@ eyeneko_sources = [
   'elements/downscale.vala',
   'elements/focus_analyze.vala',
   'elements/gl_filter.vala',
+  'elements/color_correction_matrix.vala',
 ]
 
 vapi_dir = meson.current_source_dir() / 'vapi'