source/effects/colorcurve.cpp

   1 #include <cmath>
   2 #include "color.h"
   3 #include "colorcurve.h"
   4 #include "mesh.h"
   5 #include "renderer.h"
   6 #include "resources.h"
   7 #include "texture2d.h"
   8
   9 using namespace std;
  10
  11 namespace Msp {
  12 namespace GL {
  13
  14 ColorCurve::ColorCurve():
  15         shprog(Resources::get_global().get<Program>("_colorcurve.glsl.shader")),
  16         quad(Resources::get_global().get<Mesh>("_fullscreen_quad.mesh")),
  17         linear_sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp")),
  18         nearest_sampler(Resources::get_global().get<Sampler>("_nearest_clamp.samp"))
  19 {
  20         curve.storage(LUMINANCE8, 256, 1);
  21
  22         set_exposure_adjust(0.0f);
  23         set_brightness_response(0.4f);
  24         set_linear();
  25 }
  26
  27 void ColorCurve::set_exposure_adjust(float e)
  28 {
  29         shdata.uniform("exposure", pow(2.0f, e));
  30 }
  31
  32 void ColorCurve::set_brightness_response(float b)
  33 {
  34         if(b<=0 || b>1)
  35                 throw invalid_argument("ColorCurve::set_brightness_response");
  36         // Calculate an offset value to obtain a derivative of 1 at zero intensity.
  37         float t = (b<1 ? pow(b, 1/(1-b)) : 0.0f);
  38         shdata.uniform("brightness_response", b, t, pow(t, b));
  39 }
  40
  41 void ColorCurve::set_gamma(float g)
  42 {
  43         if(g<0.1 || g>10)
  44                 throw invalid_argument("ColorCurve::set_gamma");
  45
  46         unsigned char curve_data[256];
  47         for(unsigned i=0; i<256; ++i)
  48                 curve_data[i] = pow(i/255.0f, 1/g)*255+0.5f;
  49         curve.image(0, curve_data);
  50 }
  51
  52 void ColorCurve::set_srgb()
  53 {
  54         unsigned char curve_data[256];
  55         curve_data[0] = 0;
  56         for(unsigned i=1; i<256; ++i)
  57                 curve_data[i] = to_srgb(i/255.0f)*255+0.5f;
  58         curve.image(0, curve_data);
  59 }
  60
  61 void ColorCurve::set_linear()
  62 {
  63         unsigned char curve_data[256];
  64         for(unsigned i=0; i<256; ++i)
  65                 curve_data[i] = i;
  66         curve.image(0, curve_data);
  67 }
  68
  69 void ColorCurve::render(Renderer &renderer, const Texture2D &color_buf, const Texture2D &)
  70 {
  71         Renderer::Push push(renderer);
  72         renderer.set_shader_program(&shprog, &shdata);
  73         renderer.set_texture("source", &color_buf, &nearest_sampler);
  74         renderer.set_texture("curve", &curve, &linear_sampler);
  75         quad.draw(renderer);
  76 }
  77
  78 void ColorCurve::set_debug_name(const string &name)
  79 {
  80 #ifdef DEBUG
  81         shdata.set_debug_name(name+" [UBO]");
  82         curve.set_debug_name(name+"/curve.tex1d");
  83 #else
  84         (void)name;
  85 #endif
  86 }
  87
  88
  89 ColorCurve *ColorCurve::Template::create(unsigned, unsigned) const
  90 {
  91         RefPtr<ColorCurve> colorcurve = new ColorCurve();
  92         colorcurve->set_exposure_adjust(exposure_adjust);
  93         colorcurve->set_brightness_response(brightness_response);
  94         if(srgb)
  95                 colorcurve->set_srgb();
  96         else
  97                 colorcurve->set_gamma(gamma);
  98         return colorcurve.release();
  99 }
 100
 101
 102 ColorCurve::Template::Loader::Loader(Template &t):
 103         DataFile::DerivedObjectLoader<Template, PostProcessor::Template::Loader>(t)
 104 {
 105         add("brightness_response", &Template::brightness_response);
 106         add("exposure_adjust", &Template::exposure_adjust);
 107         add("gamma", &Loader::gamma);
 108         add("srgb", &Loader::srgb);
 109 }
 110
 111 void ColorCurve::Template::Loader::gamma(float g)
 112 {
 113         obj.gamma = g;
 114         obj.srgb = false;
 115 }
 116
 117 void ColorCurve::Template::Loader::srgb()
 118 {
 119         obj.srgb = true;
 120 }
 121
 122 } // namespace GL
 123 } // namespace Msp