libobs: Add obs_get_opaque_effect function

This returns a common effect useful for rendering an image with the
alpha channel overridden to 1.0.

libobs/data/opaque.effect

+uniform float4x4 ViewProj;
+uniform texture2d image;
+
+sampler_state def_sampler {
+	Filter   = Linear;
+	AddressU = Clamp;
+	AddressV = Clamp;
+};
+
+struct VertInOut {
+	float4 pos : POSITION;
+	float2 uv  : TEXCOORD0;
+};
+
+VertInOut VSDefault(VertInOut vert_in)
+{
+	VertInOut vert_out;
+	vert_out.pos = mul(float4(vert_in.pos.xyz, 1.0), ViewProj);
+	vert_out.uv  = vert_in.uv;
+	return vert_out;
+}
+
+float4 PSDraw(VertInOut vert_in) : TARGET
+{
+	return float4(image.Sample(def_sampler, vert_in.uv).rgb, 1.0);
+}
+
+technique Draw
+{
+	pass
+	{
+		vertex_shader = VSDefault(vert_in);
+		pixel_shader  = PSDraw(vert_in);
+	}
+}

libobs/obs-internal.h

@@ -147,6 +147,7 @@ struct obs_core_video {
 	struct circlebuf                vframe_info_buffer;
 	gs_effect_t                     *default_effect;
 	gs_effect_t                     *default_rect_effect;
+	gs_effect_t                     *opaque_effect;
 	gs_effect_t                     *solid_effect;
 	gs_effect_t                     *conversion_effect;
 	gs_effect_t                     *bicubic_effect;

libobs/obs.c

@@ -229,6 +229,11 @@ static int obs_init_graphics(struct obs_video_info *ovi)
 		bfree(filename);
 	}
 
+	filename = find_libobs_data_file("opaque.effect");
+	video->opaque_effect = gs_effect_create_from_file(filename,
+			NULL);
+	bfree(filename);
+
 	filename = find_libobs_data_file("solid.effect");
 	video->solid_effect = gs_effect_create_from_file(filename,
 			NULL);
@@ -255,6 +260,8 @@ static int obs_init_graphics(struct obs_video_info *ovi)
 		if (!video->default_rect_effect)
 			success = false;
 	}
+	if (!video->opaque_effect)
+		success = false;
 	if (!video->solid_effect)
 		success = false;
 	if (!video->conversion_effect)
@@ -411,6 +418,7 @@ static void obs_free_graphics(void)
 
 		gs_effect_destroy(video->default_effect);
 		gs_effect_destroy(video->default_rect_effect);
+		gs_effect_destroy(video->opaque_effect);
 		gs_effect_destroy(video->solid_effect);
 		gs_effect_destroy(video->conversion_effect);
 		gs_effect_destroy(video->bicubic_effect);
@@ -1165,6 +1173,12 @@ gs_effect_t *obs_get_default_rect_effect(void)
 	return obs->video.default_rect_effect;
 }
 
+gs_effect_t *obs_get_opaque_effect(void)
+{
+	if (!obs) return NULL;
+	return obs->video.opaque_effect;
+}
+
 gs_effect_t *obs_get_solid_effect(void)
 {
 	if (!obs) return NULL;

libobs/obs.h

@@ -494,6 +494,9 @@ EXPORT gs_effect_t *obs_get_default_effect(void);
 /** Returns the default effect for generic RGB/YUV drawing using texture_rect */
 EXPORT gs_effect_t *obs_get_default_rect_effect(void);
 
+/** Returns the default effect for generic RGB/YUV drawing (alpha set to 1) */
+EXPORT gs_effect_t *obs_get_opaque_effect(void);
+
 /** Returns the solid effect for drawing solid colors */
 EXPORT gs_effect_t *obs_get_solid_effect(void);