X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=blur_effect.cpp;h=7ca895a15f6b56b8dfee4e53a0f013610097d0de;hp=e945295da641dd565c74b54684be93e158de0022;hb=75c27c449aabb27ed0b028b57b20d70005a6e447;hpb=b5e3174594efe9a920621a68d3b28f5e44676d03

diff --git a/blur_effect.cpp b/blur_effect.cpp
index e945295..7ca895a 100644
--- a/blur_effect.cpp
+++ b/blur_effect.cpp
@@ -8,7 +8,7 @@
 #include "util.h"
 
 BlurEffect::BlurEffect()
-	: radius(0.3f)
+	: radius(3.0f)
 {
 	register_float("radius", (float *)&radius);
 }
@@ -21,4 +21,36 @@ std::string BlurEffect::output_fragment_shader()
 void BlurEffect::set_uniforms(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
 {
 	Effect::set_uniforms(glsl_program_num, prefix, sampler_num);
+
+	// We only have 15 taps to work with, and we want that to reach out to about 2.5*sigma.
+	// Bump up the mipmap levels (giving us box blurs) until we have what we need.
+	unsigned base_mipmap_level = 0;
+	float adjusted_radius = radius;
+	float pixel_size = 1.0f;
+	while (adjusted_radius * 2.5f > 7.0f) {
+		++base_mipmap_level;
+		adjusted_radius *= 0.5f;
+		pixel_size *= 2.0f;
+	}	
+
+	glActiveTexture(GL_TEXTURE0);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, base_mipmap_level);
+	check_error();
+
+	set_uniform_float(glsl_program_num, prefix, "pixel_offset", pixel_size / 1280.0f);  // FIXME
+
+	// Simple Gaussian weights for now.
+	float weight[15], total = 0.0f;
+	for (unsigned i = 0; i < 15; ++i) {
+		float z = (i - 7.0f) / adjusted_radius;
+		weight[i] = exp(-(z*z));
+		total += weight[i];
+	}
+	printf("[mip level %d] ", base_mipmap_level);
+	for (unsigned i = 0; i < 15; ++i) {
+		weight[i] /= total;
+		printf("%f ", weight[i]);
+	}
+	printf("\n");
+	set_uniform_float_array(glsl_program_num, prefix, "weight", weight, 15);
 }