From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Tue, 16 Oct 2012 22:15:15 +0000 (+0200)
Subject: Add a high-cutoff filter to the glow effect.
X-Git-Tag: 1.0~229
X-Git-Url: https://git.sesse.net/?p=movit;a=commitdiff_plain;h=771acfe782f3052bb7326ee7f066ed78657754b4

Add a high-cutoff filter to the glow effect.
---

diff --git a/glow_effect.cpp b/glow_effect.cpp
index 0868eb0..a477505 100644
--- a/glow_effect.cpp
+++ b/glow_effect.cpp
@@ -9,10 +9,13 @@
 
 GlowEffect::GlowEffect()
 	: blur(new BlurEffect),
+	  cutoff(new HighlightCutoffEffect),
 	  mix(new MixEffect)
 {
+	blur->set_float("radius", 20.0f);
 	mix->set_float("strength_first", 1.0f);
-	mix->set_float("strength_second", 0.3f);
+	mix->set_float("strength_second", 1.0f);
+	cutoff->set_float("cutoff", 0.2f);
 }
 
 void GlowEffect::rewrite_graph(EffectChain *graph, Node *self)
@@ -22,8 +25,10 @@ void GlowEffect::rewrite_graph(EffectChain *graph, Node *self)
 
 	Node *blur_node = graph->add_node(blur);
 	Node *mix_node = graph->add_node(mix);
+	Node *cutoff_node = graph->add_node(cutoff);
 	graph->replace_receiver(self, mix_node);
-	graph->connect_nodes(input, blur_node);
+	graph->connect_nodes(input, cutoff_node);
+	graph->connect_nodes(cutoff_node, blur_node);
 	graph->connect_nodes(blur_node, mix_node);
 	graph->replace_sender(self, mix_node);
 
@@ -34,5 +39,19 @@ bool GlowEffect::set_float(const std::string &key, float value) {
 	if (key == "blurred_mix_amount") {
 		return mix->set_float("strength_second", value);
 	}
+	if (key == "highlight_cutoff") {
+		return cutoff->set_float("cutoff", value);
+	}
 	return blur->set_float(key, value);
 }
+
+HighlightCutoffEffect::HighlightCutoffEffect()
+	: cutoff(0.0f)
+{
+	register_float("cutoff", &cutoff);
+}
+
+std::string HighlightCutoffEffect::output_fragment_shader()
+{
+	return read_file("highlight_cutoff_effect.frag");
+}
diff --git a/glow_effect.h b/glow_effect.h
index 04b48f9..8b21e52 100644
--- a/glow_effect.h
+++ b/glow_effect.h
@@ -1,12 +1,14 @@
 #ifndef _GLOW_EFFECT_H
 #define _GLOW_EFFECT_H 1
 
-// Glow: Simply add a blurred version of the image to itself.
+// Glow: Cut out the highlights of the image (everything above a certain threshold),
+// blur them, and overlay them onto the original image.
 
 #include "effect.h"
 
 class BlurEffect;
 class MixEffect;
+class HighlightCutoffEffect;
 
 class GlowEffect : public Effect {
 public:
@@ -27,7 +29,22 @@ public:
 
 private:
 	BlurEffect *blur;
+	HighlightCutoffEffect *cutoff;
 	MixEffect *mix;
 };
 
+// An effect that cuts out only the highlights of an image;
+// anything at the cutoff or below is set to 0.0, and then all other pixels
+// get the cutoff subtracted. Used only as part of GlowEffect.
+
+class HighlightCutoffEffect : public Effect {
+public:
+	HighlightCutoffEffect();
+	virtual std::string effect_type_id() const { return "HighlightCutoffEffect"; }
+	std::string output_fragment_shader();
+
+private:
+	float cutoff;
+};
+
 #endif // !defined(_GLOW_EFFECT_H)
diff --git a/highlight_cutoff_effect.frag b/highlight_cutoff_effect.frag
new file mode 100644
index 0000000..cb76630
--- /dev/null
+++ b/highlight_cutoff_effect.frag
@@ -0,0 +1,3 @@
+vec4 FUNCNAME(vec2 tc) {
+	return max(INPUT(tc) - vec4(PREFIX(cutoff)), 0.0);
+}