X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=dither_effect.cpp;h=14132bd43407bda72a7d2a8ca86f785bc9e1fab1;hp=1399c8196984c728ac148ea686f4ab9de504e403;hb=9651a4eaae012cdc49c1aa38197861e04f62e91e;hpb=29072985d0a00a53e5b578a1444cee61a0c9e1f2

diff --git a/dither_effect.cpp b/dither_effect.cpp
index 1399c81..14132bd 100644
--- a/dither_effect.cpp
+++ b/dither_effect.cpp
@@ -1,10 +1,15 @@
-#include <math.h>
-#include <assert.h>
 #include <GL/glew.h>
+#include <assert.h>
+#include <stdio.h>
+#include <algorithm>
 
 #include "dither_effect.h"
+#include "effect_util.h"
+#include "init.h"
 #include "util.h"
 
+using namespace std;
+
 namespace {
 
 // A simple LCG (linear congruental generator) random generator.
@@ -37,12 +42,14 @@ DitherEffect::~DitherEffect()
 	glDeleteTextures(1, &texnum);
 }
 
-std::string DitherEffect::output_fragment_shader()
+string DitherEffect::output_fragment_shader()
 {
-	return read_file("dither_effect.frag");
+	char buf[256];
+	sprintf(buf, "#define NEED_EXPLICIT_ROUND %d\n", (movit_num_wrongly_rounded > 0));
+	return buf + read_file("dither_effect.frag");
 }
 
-void DitherEffect::update_texture(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+void DitherEffect::update_texture(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
 {
 	float *dither_noise = new float[width * height];
 	float dither_double_amplitude = 1.0f / (1 << num_bits);
@@ -50,8 +57,8 @@ void DitherEffect::update_texture(GLuint glsl_program_num, const std::string &pr
 	// We don't need a strictly nonrepeating dither; reducing the resolution
 	// to max 128x128 saves a lot of texture bandwidth, without causing any
 	// noticeable harm to the dither's performance.
-	texture_width = std::min(width, 128);
-	texture_height = std::min(height, 128);
+	texture_width = min(width, 128);
+	texture_height = min(height, 128);
 
 	// Using the resolution as a seed gives us a consistent dither from frame to frame.
 	// It also gives a different dither for e.g. different aspect ratios, which _feels_
@@ -81,10 +88,14 @@ void DitherEffect::update_texture(GLuint glsl_program_num, const std::string &pr
 	delete[] dither_noise;
 }
 
-void DitherEffect::set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+void DitherEffect::set_gl_state(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
 {
 	Effect::set_gl_state(glsl_program_num, prefix, sampler_num);
 
+	assert(width > 0);
+	assert(height > 0);
+	assert(num_bits > 0);
+
 	if (width != last_width || height != last_height || num_bits != last_num_bits) {
 		update_texture(glsl_program_num, prefix, sampler_num);
 		last_width = width;
@@ -105,4 +116,9 @@ void DitherEffect::set_gl_state(GLuint glsl_program_num, const std::string &pref
 	// we don't have to worry about it.	
 	float tc_scale[] = { float(width) / float(texture_width), float(height) / float(texture_height) };
 	set_uniform_vec2(glsl_program_num, prefix, "tc_scale", tc_scale);
+
+	// Used if the shader needs to do explicit rounding.
+	int round_fac = (1 << num_bits) - 1;
+	set_uniform_float(glsl_program_num, prefix, "round_fac", round_fac);
+	set_uniform_float(glsl_program_num, prefix, "inv_round_fac", 1.0f / round_fac);
 }