Merge pull request #1808 from jpark37/area-filter-gl-flip

libobs: Fix and simplify Area scale filter

libobs/data/area.effect

@@ -5,12 +5,6 @@ uniform float3 color_range_max = {1.0, 1.0, 1.0};
 uniform float2 base_dimension_i;
 uniform texture2d image;
 
-sampler_state def_sampler {
-	Filter   = Linear;
-	AddressU = Clamp;
-	AddressV = Clamp;
-};
-
 struct VertInOut {
 	float4 pos : POSITION;
 	float2 uv  : TEXCOORD0;
@@ -31,6 +25,9 @@ float4 PSDrawAreaRGBA(VertInOut vert_in) : TARGET
 	float2 uv = vert_in.uv;
 	float2 uvdelta = float2(ddx(uv.x), ddy(uv.y));
 
+	// Handle potential OpenGL flip.
+	uvdelta.y = abs(uvdelta.y);
+
 	float2 uvhalfdelta = 0.5 * uvdelta;
 	float2 uvmin = uv - uvhalfdelta;
 	float2 uvmax = uv + uvhalfdelta;
@@ -39,19 +36,20 @@ float4 PSDrawAreaRGBA(VertInOut vert_in) : TARGET
 	int2 loadindexmax = int2(uvmax / base_dimension_i);
 
 	float2 targetpos = uv / uvdelta;
-	float2 targetposleft = targetpos - 0.5;
-	float2 targetposright = targetpos + 0.5;
+	float2 targetposmin = targetpos - 0.5;
+	float2 targetposmax = targetpos + 0.5;
+	float2 scale = base_dimension_i / uvdelta;
 	for (int loadindexy = loadindexmin.y; loadindexy <= loadindexmax.y; ++loadindexy)
 	{
 		for (int loadindexx = loadindexmin.x; loadindexx <= loadindexmax.x; ++loadindexx)
 		{
-			float2 loadindex = float2(loadindexx, loadindexy);
-			float2 potentialtargetmin = loadindex / uvdelta * base_dimension_i;
-			float2 potentialtargetmax = (loadindex + 1.0) / uvdelta * base_dimension_i;
-			float2 targetmin = max(potentialtargetmin, targetposleft);
-			float2 targetmax = min(potentialtargetmax, targetposright);
+			int2 loadindex = int2(loadindexx, loadindexy);
+			float2 potentialtargetmin = float2(loadindex) * scale;
+			float2 potentialtargetmax = potentialtargetmin + scale;
+			float2 targetmin = max(potentialtargetmin, targetposmin);
+			float2 targetmax = min(potentialtargetmax, targetposmax);
 			float area = (targetmax.x - targetmin.x) * (targetmax.y - targetmin.y);
-			float4 sample = image.SampleLevel(def_sampler, (loadindex + 0.5) * base_dimension_i, 0.0);
+			float4 sample = image.Load(int3(loadindex, 0));
 			totalcolor += area * float4(sample.rgb * sample.a, sample.a);
 		}
 	}
@@ -72,6 +70,9 @@ float4 PSDrawAreaMatrix(VertInOut vert_in) : TARGET
 	float2 uv = vert_in.uv;
 	float2 uvdelta = float2(ddx(uv.x), ddy(uv.y));
 
+	// Handle potential OpenGL flip.
+	uvdelta.y = abs(uvdelta.y);
+
 	float2 uvhalfdelta = 0.5 * uvdelta;
 	float2 uvmin = uv - uvhalfdelta;
 	float2 uvmax = uv + uvhalfdelta;
@@ -80,19 +81,20 @@ float4 PSDrawAreaMatrix(VertInOut vert_in) : TARGET
 	int2 loadindexmax = int2(uvmax / base_dimension_i);
 
 	float2 targetpos = uv / uvdelta;
-	float2 targetposleft = targetpos - 0.5;
-	float2 targetposright = targetpos + 0.5;
+	float2 targetposmin = targetpos - 0.5;
+	float2 targetposmax = targetpos + 0.5;
+	float2 scale = base_dimension_i / uvdelta;
 	for (int loadindexy = loadindexmin.y; loadindexy <= loadindexmax.y; ++loadindexy)
 	{
 		for (int loadindexx = loadindexmin.x; loadindexx <= loadindexmax.x; ++loadindexx)
 		{
-			float2 loadindex = float2(loadindexx, loadindexy);
-			float2 potentialtargetmin = loadindex / uvdelta * base_dimension_i;
-			float2 potentialtargetmax = (loadindex + 1.0) / uvdelta * base_dimension_i;
-			float2 targetmin = max(potentialtargetmin, targetposleft);
-			float2 targetmax = min(potentialtargetmax, targetposright);
+			int2 loadindex = int2(loadindexx, loadindexy);
+			float2 potentialtargetmin = float2(loadindex) * scale;
+			float2 potentialtargetmax = potentialtargetmin + scale;
+			float2 targetmin = max(potentialtargetmin, targetposmin);
+			float2 targetmax = min(potentialtargetmax, targetposmax);
 			float area = (targetmax.x - targetmin.x) * (targetmax.y - targetmin.y);
-			float3 yuv = image.SampleLevel(def_sampler, (loadindex + 0.5) * base_dimension_i, 0.0).xyz;
+			float3 yuv = image.Load(int3(loadindex, 0)).xyz;
 			totalcolor += area * ConvertFromYuv(yuv);
 		}
 	}

libobs/obs-scene.c

@@ -488,11 +488,6 @@ static void render_item_texture(struct obs_scene_item *item)
 				effect = obs->video.lanczos_effect;
 			} else if (type == OBS_SCALE_AREA) {
 				effect = obs->video.area_effect;
-
-				gs_eparam_t *image = gs_effect_get_param_by_name(
-					effect, "image");
-				gs_effect_set_next_sampler(image,
-					obs->video.point_sampler);
 			}
 
 			scale_param = gs_effect_get_param_by_name(effect,