X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=resample_effect.cpp;h=74b059404332cbab2da91d7e403954997df96a9d;hp=c2ef531d3dee6b9fa272bebfe2f97086ce23126a;hb=7f1c8bb8b3ce08b94054f0a8990e5b8225d36036;hpb=6f0d068e83d8aa03e1d530d02762da199fc5a1ff

diff --git a/resample_effect.cpp b/resample_effect.cpp
index c2ef531..74b0594 100644
--- a/resample_effect.cpp
+++ b/resample_effect.cpp
@@ -1,7 +1,7 @@
 // Three-lobed Lanczos, the most common choice.
 #define LANCZOS_RADIUS 3.0
 
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 #include <assert.h>
 #include <limits.h>
 #include <math.h>
@@ -13,6 +13,10 @@
 #include "resample_effect.h"
 #include "util.h"
 
+using namespace std;
+
+namespace movit {
+
 namespace {
 
 float sinc(float x)
@@ -155,7 +159,7 @@ 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();
@@ -193,7 +197,7 @@ 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));
@@ -212,7 +216,7 @@ std::string SingleResamplePassEffect::output_fragment_shader()
 //
 // For horizontal scaling, we fill in the exact same texture;
 // the shader just interprets it differently.
-void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
 {
 	unsigned src_size, dst_size;
 	if (direction == SingleResamplePassEffect::HORIZONTAL) {
@@ -227,7 +231,6 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const std
 		assert(false);
 	}
 
-
 	// For many resamplings (e.g. 640 -> 1280), we will end up with the same
 	// set of samples over and over again in a loop. Thus, we can compute only
 	// the first such loop, and then ask the card to repeat the texture for us.
@@ -286,7 +289,7 @@ 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];
@@ -303,6 +306,7 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const std
 			weights[(y * src_samples + i) * 2 + 0] = weight * radius_scaling_factor;
 			weights[(y * src_samples + i) * 2 + 1] = (src_y + 0.5) / float(src_size);
 		}
+
 	}
 
 	// Now make use of the bilinear filtering in the GPU to reduce the number of samples
@@ -316,7 +320,7 @@ 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.
@@ -328,6 +332,18 @@ void SingleResamplePassEffect::update_texture(GLuint glsl_program_num, const std
 			src_samples,
 			src_samples - src_bilinear_samples);
 		assert(int(src_samples) - int(num_samples_saved) == src_bilinear_samples);
+
+		// Normalize so that the sum becomes one. Note that we do it twice;
+		// this sometimes helps a tiny little bit when we have many samples.
+		for (int normalize_pass = 0; normalize_pass < 2; ++normalize_pass) {
+			float sum = 0.0;
+			for (int i = 0; i < src_bilinear_samples; ++i) {
+				sum += bilinear_weights[(y * src_bilinear_samples + i) * 2 + 0];
+			}
+			for (int i = 0; i < src_bilinear_samples; ++i) {
+				bilinear_weights[(y * src_bilinear_samples + i) * 2 + 0] /= sum;
+			}
+		}
 	}	
 
 	// Encode as a two-component texture. Note the GL_REPEAT.
@@ -348,7 +364,7 @@ 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);
 
@@ -390,3 +406,5 @@ void SingleResamplePassEffect::set_gl_state(GLuint glsl_program_num, const std::
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 	check_error();
 }
+
+}  // namespace movit