X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=resample_effect.cpp;h=6c490f141bc1a87b9f86db44b90b5d64f75d0dd7;hp=e1e6199ec5b5b857add0df623d6fd05a25d4b1e0;hb=453aa5c00561e4c73297f69e9f7c492a678e9699;hpb=9447b2d234394c1d966f77ed87271a3625a81cdd

diff --git a/resample_effect.cpp b/resample_effect.cpp
index e1e6199..6c490f1 100644
--- a/resample_effect.cpp
+++ b/resample_effect.cpp
@@ -1,13 +1,19 @@
 // Three-lobed Lanczos, the most common choice.
 #define LANCZOS_RADIUS 3.0
 
-#include <math.h>
+#include <GL/glew.h>
 #include <assert.h>
+#include <limits.h>
+#include <math.h>
+#include <stdio.h>
+#include <algorithm>
 
-#include "resample_effect.h"
 #include "effect_chain.h"
+#include "effect_util.h"
+#include "resample_effect.h"
 #include "util.h"
-#include "opengl.h"
+
+using namespace std;
 
 namespace {
 
@@ -74,9 +80,12 @@ unsigned combine_samples(float *src, float *dst, unsigned num_src_samples, unsig
 		float offset, total_weight, sum_sq_error;
 		combine_two_samples(w1, w2, &offset, &total_weight, &sum_sq_error);
 
-		// If the interpolation error is larger than that of one level
-		// at 8-bit precision, don't combine.
-		if (sum_sq_error > 1.0f / (256.0f * 256.0f)) {
+		// If the interpolation error is larger than that of about sqrt(2) of
+		// a level at 8-bit precision, don't combine. (You'd think 1.0 was enough,
+		// but since the artifacts are not really random, they can get quite
+		// visible. On the other hand, going to 0.25f, I can see no change at
+		// all with 8-bit output, so it would not seem to be worth it.)
+		if (sum_sq_error > 0.5f / (256.0f * 256.0f)) {
 			continue;
 		}
 
@@ -148,7 +157,7 @@ void ResampleEffect::update_size()
 	assert(ok);
 }
 
-bool ResampleEffect::set_float(const std::string &key, float value) {
+bool ResampleEffect::set_float(const string &key, float value) {
 	if (key == "width") {
 		output_width = value;
 		update_size();
@@ -186,7 +195,7 @@ SingleResamplePassEffect::~SingleResamplePassEffect()
 	glDeleteTextures(1, &texnum);
 }
 
-std::string SingleResamplePassEffect::output_fragment_shader()
+string SingleResamplePassEffect::output_fragment_shader()
 {
 	char buf[256];
 	sprintf(buf, "#define DIRECTION_VERTICAL %d\n", (direction == VERTICAL));
@@ -204,8 +213,8 @@ std::string SingleResamplePassEffect::output_fragment_shader()
 // so out[0] will read from parameters <x,y> = <0,0>, <1,0>, <2,0> and so on.
 //
 // For horizontal scaling, we fill in the exact same texture;
-// the shader just interprets is differently.
-void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+// the shader just interprets it differently.
+void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
 {
 	unsigned src_size, dst_size;
 	if (direction == SingleResamplePassEffect::HORIZONTAL) {
@@ -279,7 +288,7 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const std
 	// Anyhow, in this case we clearly need to look at more source pixels
 	// to compute the destination pixel, and how many depend on the scaling factor.
 	// Thus, the kernel width will vary with how much we scale.
-	float radius_scaling_factor = std::min(float(dst_size) / float(src_size), 1.0f);
+	float radius_scaling_factor = min(float(dst_size) / float(src_size), 1.0f);
 	int int_radius = lrintf(LANCZOS_RADIUS / radius_scaling_factor);
 	int src_samples = int_radius * 2 + 1;
 	float *weights = new float[dst_samples * src_samples * 2];
@@ -309,7 +318,7 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const std
 	src_bilinear_samples = 0;
 	for (unsigned y = 0; y < dst_samples; ++y) {
 		unsigned num_samples_saved = combine_samples(weights + (y * src_samples) * 2, NULL, src_samples, UINT_MAX);
-		src_bilinear_samples = std::max<int>(src_bilinear_samples, src_samples - num_samples_saved);
+		src_bilinear_samples = max<int>(src_bilinear_samples, src_samples - num_samples_saved);
 	}
 
 	// Now that we know the right width, actually combine the samples.
@@ -341,10 +350,15 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const std
 	delete[] bilinear_weights;
 }
 
-void SingleResamplePassEffect::set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+void SingleResamplePassEffect::set_gl_state(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
 {
 	Effect::set_gl_state(glsl_program_num, prefix, sampler_num);
 
+	assert(input_width > 0);
+	assert(input_height > 0);
+	assert(output_width > 0);
+	assert(output_height > 0);
+
 	if (input_width != last_input_width ||
 	    input_height != last_input_height ||
 	    output_width != last_output_width ||