Add clear pass for metal

Shaders/clear_pass/clear_pass.frag.glsl

@@ -0,0 +1,9 @@
+#version 450
+
+in vec2 texCoord;
+out vec4 fragColor;
+
+void main() {
+	fragColor = vec4(0.0, 0.0, 0.0, 1.0);
+	gl_FragDepth = 1.0;
+}

Shaders/clear_pass/clear_pass.json

@@ -0,0 +1,14 @@
+{
+	"contexts": [
+		{
+			"name": "clear_pass",
+			"depth_write": true,
+			"compare_mode": "always",
+			"cull_mode": "none",
+			"links": [],
+			"texture_params": [],
+			"vertex_shader": "../include/pass.vert.glsl",
+			"fragment_shader": "clear_pass.frag.glsl"
+		}
+	]
+}

Sources/armory/renderpath/RenderPathForward.hx

@@ -62,6 +62,13 @@ class RenderPathForward {
 
 		path = _path;
 
+		#if kha_metal
+		{
+			path.loadShader("shader_datas/clear_pass/clear_pass");
+			path.clearShader = "shader_datas/clear_pass/clear_pass";
+		}