X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=blur_effect.cpp;h=80aef747c8a6bba0da40f20b0a06e91b810e2937;hp=b48dc956e59dade84e49ac507de998dc4241f45d;hb=2b6a8585772bf9ae742a2ee36144a0cdd5ba0524;hpb=322c03693ae23e5a5843dee9dcb74dfb3b7d43d8

diff --git a/blur_effect.cpp b/blur_effect.cpp
index b48dc95..80aef74 100644
--- a/blur_effect.cpp
+++ b/blur_effect.cpp
@@ -1,13 +1,17 @@
-#include <math.h>
+#include <GL/glew.h>
 #include <assert.h>
+#include <math.h>
+#include <algorithm>
 
 #include "blur_effect.h"
 #include "effect_chain.h"
+#include "effect_util.h"
 #include "util.h"
-#include "opengl.h"
 
 // Must match blur_effect.frag.
 #define NUM_TAPS 16
+
+using namespace std;
 	
 BlurEffect::BlurEffect()
 	: radius(3.0f),
@@ -16,9 +20,9 @@ BlurEffect::BlurEffect()
 {
 	// The first blur pass will forward resolution information to us.
 	hpass = new SingleBlurPassEffect(this);
-	hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL);
+	CHECK(hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL));
 	vpass = new SingleBlurPassEffect(NULL);
-	vpass->set_int("direction", SingleBlurPassEffect::VERTICAL);
+	CHECK(vpass->set_int("direction", SingleBlurPassEffect::VERTICAL));
 
 	update_radius();
 }
@@ -54,8 +58,8 @@ void BlurEffect::update_radius()
 	float adjusted_radius = radius;
 	while ((mipmap_width > 1 || mipmap_height > 1) && adjusted_radius * 1.5f > NUM_TAPS / 2) {
 		// Find the next mipmap size (round down, minimum 1 pixel).
-		mipmap_width = std::max(mipmap_width / 2, 1u);
-		mipmap_height = std::max(mipmap_height / 2, 1u);
+		mipmap_width = max(mipmap_width / 2, 1u);
+		mipmap_height = max(mipmap_height / 2, 1u);
 
 		// Approximate when mipmap sizes are odd, but good enough.
 		adjusted_radius = radius * float(mipmap_width) / float(input_width);
@@ -64,15 +68,19 @@ void BlurEffect::update_radius()
 	bool ok = hpass->set_float("radius", adjusted_radius);
 	ok |= hpass->set_int("width", mipmap_width);
 	ok |= hpass->set_int("height", mipmap_height);
+	ok |= hpass->set_int("virtual_width", mipmap_width);
+	ok |= hpass->set_int("virtual_height", mipmap_height);
 
 	ok |= vpass->set_float("radius", adjusted_radius);
 	ok |= vpass->set_int("width", mipmap_width);
 	ok |= vpass->set_int("height", mipmap_height);
+	ok |= vpass->set_int("virtual_width", input_width);
+	ok |= vpass->set_int("virtual_height", input_height);
 
 	assert(ok);
 }
 
-bool BlurEffect::set_float(const std::string &key, float value) {
+bool BlurEffect::set_float(const string &key, float value) {
 	if (key == "radius") {
 		radius = value;
 		update_radius();
@@ -92,14 +100,16 @@ SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent)
 	register_int("direction", (int *)&direction);
 	register_int("width", &width);
 	register_int("height", &height);
+	register_int("virtual_width", &virtual_width);
+	register_int("virtual_height", &virtual_height);
 }
 
-std::string SingleBlurPassEffect::output_fragment_shader()
+string SingleBlurPassEffect::output_fragment_shader()
 {
 	return read_file("blur_effect.frag");
 }
 
-void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
 {
 	Effect::set_gl_state(glsl_program_num, prefix, sampler_num);
 
@@ -114,12 +124,16 @@ void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const std::stri
 	} else {
 		float sum = 0.0f;
 		for (unsigned i = 0; i < NUM_TAPS + 1; ++i) {
-			float z = i / radius;
-
 			// Gaussian blur is a common, but maybe not the prettiest choice;
 			// it can feel a bit too blurry in the fine detail and too little
 			// long-tail. This is a simple logistic distribution, which has
 			// a narrower peak but longer tails.
+			//
+			// We interpret the radius as sigma, similar to Gaussian blur.
+			// Wikipedia says that sigma² = pi² s² / 3, which yields:
+			const float s = (sqrt(3.0) / M_PI) * radius;
+			float z = i / (2.0 * s);
+
 			weight[i] = 1.0f / (cosh(z) * cosh(z));
 
 			if (i == 0) {
@@ -158,13 +172,8 @@ void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const std::stri
 		float w2 = weight[base_pos + 1];
 
 		float offset, total_weight;
-		if (w1 + w2 < 1e-6) {
-			offset = 0.5f;
-			total_weight = 0.0f;
-		} else {
-			offset = w2 / (w1 + w2);
-			total_weight = w1 + w2;
-		}
+		combine_two_samples(w1, w2, &offset, &total_weight, NULL);
+
 		float x = 0.0f, y = 0.0f;
 
 		if (direction == HORIZONTAL) {