X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=util.cpp;h=4e6a31c70502cba2687197cba2549b791f4da98c;hp=592e4d56b47f842a6bb6493e634992bb9cfe0ec5;hb=e22b57d30085d193da7829e0bc082ad1a310963e;hpb=02d19b8323a1b626acd9d3b4f08bb63f51149cf3

diff --git a/util.cpp b/util.cpp
index 592e4d5..4e6a31c 100644
--- a/util.cpp
+++ b/util.cpp
@@ -1,6 +1,13 @@
+#include <stdio.h>
 #include <math.h>
+#include <string.h>
+#include <assert.h>
+#include <GL/glew.h>
 
 #include "util.h"
+#include "init.h"
+
+extern std::string *movit_data_directory;
 
 void hsv2rgb(float h, float s, float v, float *r, float *g, float *b)
 {
@@ -42,3 +49,125 @@ void hsv2rgb(float h, float s, float v, float *r, float *g, float *b)
 	*g += m;
 	*b += m;
 }
+
+void hsv2rgb_normalized(float h, float s, float v, float *r, float *g, float *b)
+{
+	float ref_r, ref_g, ref_b;
+	hsv2rgb(h, s, v, r, g, b);
+	hsv2rgb(h, 0.0f, v, &ref_r, &ref_g, &ref_b);
+	float lum = 0.2126 * *r + 0.7152 * *g + 0.0722 * *b;
+	float ref_lum = 0.2126 * ref_r + 0.7152 * ref_g + 0.0722 * ref_b;
+	if (lum > 1e-3) {
+		float fac = ref_lum / lum;
+		*r *= fac;
+		*g *= fac;
+		*b *= fac;
+	}
+}
+
+std::string read_file(const std::string &filename)
+{
+	const std::string full_pathname = *movit_data_directory + "/" + filename;
+
+	static char buf[131072];
+	FILE *fp = fopen(full_pathname.c_str(), "r");
+	if (fp == NULL) {
+		perror(full_pathname.c_str());
+		exit(1);
+	}
+
+	int len = fread(buf, 1, sizeof(buf), fp);
+	fclose(fp);
+
+	return std::string(buf, len);
+}
+
+GLuint compile_shader(const std::string &shader_src, GLenum type)
+{
+	GLuint obj = glCreateShader(type);
+	const GLchar* source[] = { shader_src.data() };
+	const GLint length[] = { (GLint)shader_src.size() };
+	glShaderSource(obj, 1, source, length);
+	glCompileShader(obj);
+
+	GLchar info_log[4096];
+	GLsizei log_length = sizeof(info_log) - 1;
+	glGetShaderInfoLog(obj, log_length, &log_length, info_log);
+	info_log[log_length] = 0; 
+	if (strlen(info_log) > 0) {
+		printf("shader compile log: %s\n", info_log);
+	}
+
+	GLint status;
+	glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
+	if (status == GL_FALSE) {
+		exit(1);
+	}
+
+	return obj;
+}
+
+void print_3x3_matrix(const Eigen::Matrix3d& m)
+{
+	printf("%6.4f %6.4f %6.4f\n", m(0,0), m(0,1), m(0,2));
+	printf("%6.4f %6.4f %6.4f\n", m(1,0), m(1,1), m(1,2));
+	printf("%6.4f %6.4f %6.4f\n", m(2,0), m(2,1), m(2,2));
+	printf("\n");
+}
+
+std::string output_glsl_mat3(const std::string &name, const Eigen::Matrix3d &m)
+{
+	char buf[1024];
+	sprintf(buf,
+		"const mat3 %s = mat3(\n"
+		"    %.8f, %.8f, %.8f,\n"
+		"    %.8f, %.8f, %.8f,\n"
+		"    %.8f, %.8f, %.8f);\n\n",
+		name.c_str(),
+		m(0,0), m(1,0), m(2,0),
+		m(0,1), m(1,1), m(2,1),
+		m(0,2), m(1,2), m(2,2));
+	return buf;
+}
+
+void combine_two_samples(float w1, float w2, float *offset, float *total_weight, float *sum_sq_error)
+{
+	assert(movit_initialized);
+	assert(w1 * w2 >= 0.0f);  // Should not have differing signs.
+	float z;  // Just a shorter name for offset.
+	if (fabs(w1 + w2) < 1e-6) {
+		z = 0.5f;
+	} else {
+		z = w2 / (w1 + w2);
+	}
+
+	// Round to the minimum number of bits we have measured earlier.
+	// The card will do this for us anyway, but if we know what the real z
+	// is, we can pick a better total_weight below.
+	z = lrintf(z / movit_texel_subpixel_precision) * movit_texel_subpixel_precision;
+	
+	// Choose total weight w so that we minimize total squared error
+	// for the effective weights:
+	//
+	//   e = (w(1-z) - a)² + (wz - b)²
+	//
+	// Differentiating by w and setting equal to zero:
+	//
+	//   2(w(1-z) - a)(1-z) + 2(wz - b)z = 0
+	//   w(1-z)² - a(1-z) + wz² - bz = 0
+	//   w((1-z)² + z²) = a(1-z) + bz
+	//   w = (a(1-z) + bz) / ((1-z)² + z²)
+	//
+	// If z had infinite precision, this would simply reduce to w = w1 + w2.
+	*total_weight = (w1 * (1 - z) + w2 * z) / (z * z + (1 - z) * (1 - z));
+	*offset = z;
+
+	if (sum_sq_error != NULL) {
+		float err1 = *total_weight * (1 - z) - w1;
+		float err2 = *total_weight * z - w2;
+		*sum_sq_error = err1 * err1 + err2 * err2;
+	}
+
+	assert(*offset >= 0.0f);
+	assert(*offset <= 1.0f);
+}