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 "shader.h"
   8 #include "texture2d.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 ColorCurve::ColorCurve():
  16         shprog(Resources::get_global().get<Program>("_colorcurve.glsl.shader")),
  17         quad(Resources::get_global().get<Mesh>("_fullscreen_quad.mesh")),
  18         linear_sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp")),
  19         nearest_sampler(Resources::get_global().get<Sampler>("_nearest_clamp.samp"))
  20 {
  21         curve.storage(LUMINANCE8, 256, 1);
  22
  23         set_exposure_adjust(0.0f);
  24         set_brightness_response(0.4f);
  25         set_linear();
  26 }
  27
  28 void ColorCurve::set_exposure_adjust(float e)
  29 {
  30         shdata.uniform("exposure", pow(2.0f, e));
  31 }
  32
  33 void ColorCurve::set_brightness_response(float b)
  34 {
  35         if(b<=0 || b>1)
  36                 throw invalid_argument("ColorCurve::set_brightness_response");
  37         // Calculate an offset value to obtain a derivative of 1 at zero intensity.
  38         float t = (b<1 ? pow(b, 1/(1-b)) : 0.0f);
  39         shdata.uniform("brightness_response", b, t, pow(t, b));
  40 }
  41
  42 void ColorCurve::set_gamma(float g)
  43 {
  44         if(g<0.1 || g>10)
  45                 throw invalid_argument("ColorCurve::set_gamma");
  46
  47         unsigned char curve_data[256];
  48         for(unsigned i=0; i<256; ++i)
  49                 curve_data[i] = pow(i/255.0f, 1/g)*255+0.5f;
  50         curve.image(0, curve_data);
  51 }
  52
  53 void ColorCurve::set_srgb()
  54 {
  55         unsigned char curve_data[256];
  56         curve_data[0] = 0;
  57         for(unsigned i=1; i<256; ++i)
  58                 curve_data[i] = to_srgb(i/255.0f)*255+0.5f;
  59         curve.image(0, curve_data);
  60 }
  61
  62 void ColorCurve::set_linear()
  63 {
  64         unsigned char curve_data[256];
  65         for(unsigned i=0; i<256; ++i)
  66                 curve_data[i] = i;
  67         curve.image(0, curve_data);
  68 }
  69
  70 void ColorCurve::render(Renderer &renderer, const Texture2D &color_buf, const Texture2D &)
  71 {
  72         Renderer::Push push(renderer);
  73         renderer.set_shader_program(&shprog, &shdata);
  74         renderer.set_texture("source", &color_buf, &nearest_sampler);
  75         renderer.set_texture("curve", &curve, &linear_sampler);
  76         quad.draw(renderer);
  77 }
  78
  79 void ColorCurve::set_debug_name(const string &name)
  80 {
  81 #ifdef DEBUG
  82         shdata.set_debug_name(name+" [UBO]");
  83         curve.set_debug_name(name+"/curve.tex1d");
  84 #else
  85         (void)name;
  86 #endif
  87 }
  88
  89
  90 ColorCurve::Template::Template():
  91         exposure_adjust(0.0f),
  92         brightness_response(0.4f),
  93         gamma(1.0f),
  94         srgb(false)
  95 { }
  96
  97 ColorCurve *ColorCurve::Template::create(unsigned, unsigned) const
  98 {
  99         RefPtr<ColorCurve> colorcurve = new ColorCurve();
 100         colorcurve->set_exposure_adjust(exposure_adjust);
 101         colorcurve->set_brightness_response(brightness_response);
 102         if(srgb)
 103                 colorcurve->set_srgb();
 104         else
 105                 colorcurve->set_gamma(gamma);
 106         return colorcurve.release();
 107 }
 108
 109
 110 ColorCurve::Template::Loader::Loader(Template &t):
 111         DataFile::DerivedObjectLoader<Template, PostProcessor::Template::Loader>(t)
 112 {
 113         add("brightness_response", &Template::brightness_response);
 114         add("exposure_adjust", &Template::exposure_adjust);
 115         add("gamma", &Loader::gamma);
 116         add("srgb", &Loader::srgb);
 117 }
 118
 119 void ColorCurve::Template::Loader::gamma(float g)
 120 {
 121         obj.gamma = g;
 122         obj.srgb = false;
 123 }
 124
 125 void ColorCurve::Template::Loader::srgb()
 126 {
 127         obj.srgb = true;
 128 }
 129
 130 } // namespace GL
 131 } // namespace Msp