obs-filters: Add crop filter

Allows any source to be cropped, though note that this renders to
texture first, so for more optimal results, cropping values should
probably be put in to capture sources that can be cropped as they're
actually rendered by the source.

plugins/obs-filters/data/crop_filter.effect

@@ -0,0 +1,38 @@
+uniform float4x4 ViewProj;
+uniform texture2d image;
+
+uniform float2 mul_val;
+uniform float2 add_val;
+
+sampler_state textureSampler {
+	Filter    = Linear;
+	AddressU  = Clamp;
+	AddressV  = Clamp;
+};
+
+struct VertData {
+	float4 pos : POSITION;
+	float2 uv  : TEXCOORD0;
+};
+
+VertData VSCrop(VertData v_in)
+{
+	VertData vert_out;
+	vert_out.pos = mul(float4(v_in.pos.xyz, 1.0), ViewProj);
+	vert_out.uv  = v_in.uv * mul_val + add_val;
+	return vert_out;
+}
+
+float4 PSCrop(VertData v_in) : TARGET
+{
+	return image.Sample(textureSampler, v_in.uv);
+}
+
+technique Draw
+{
+	pass
+	{
+		vertex_shader = VSCrop(v_in);
+		pixel_shader  = PSCrop(v_in);
+	}
+}

plugins/obs-filters/data/locale/en-US.ini

@@ -1,5 +1,6 @@
 MaskFilter="Image Mask/Blend"
 AsyncDelayFilter="Video Delay (Async)"
+CropFilter="Crop"
 DelayMs="Delay (milliseconds)"
 Type="Type"
 MaskBlendType.MaskColor="Alpha Mask (Color Channel)"
@@ -15,3 +16,10 @@ Brightness="Brightness"
 Gamma="Gamma"
 BrowsePath.Images="All Image Files"
 BrowsePath.AllFiles="All Files"
+Crop.Left="Left"
+Crop.Right="Right"
+Crop.Top="Top"
+Crop.Bottom="Bottom"
+Crop.Width="Width"
+Crop.Height="Height"
+Crop.Relative="Relative"