paysages : HDR rendering (WIP).

git-svn-id: https://subversion.assembla.com/svn/thunderk/paysages@495 b1fd45b6-86a6-48da-8261-f70d1f35bdcc

TODO

@@ -1,4 +1,5 @@
 Technology Preview 2 :
+- Implement High Dynamic Range (with OpenEXR or Radiance file format support ?).
 - Fully move layer management from BaseForm to BaseFormLayer.
 - Replace terrain canvas editor by full sculpting editor.
    => Add a generation dialog, with fixed resolution.
@@ -43,7 +44,6 @@ Technlogy Preview 3 :
 Technology Preview 4 :
 - Restore render progress.
 - Store the terrain canvases in a tree to allow "multi-res" edition.
-- Implement High Dynamic Range.
 - Implement Sub Surface Scattering for water.
 - Use bicubic interpolation for antialiasing.
 - Allow for larger renders/antialias (will need several two-pass chunks).

gui_qt/dialogrender.cpp

@@ -26,6 +26,7 @@ static void _renderStart(int width, int height, Color background)
 
 static void _renderDraw(int x, int y, Color col)
 {
+    col = colorProfileApply(_current_dialog->_hdr_profile, col);
     _current_dialog->pixbuf->setPixel(x, _current_dialog->pixbuf->height() - 1 - y, colorToQColor(col).rgb());
 }
 
@@ -79,6 +80,8 @@ DialogRender::DialogRender(QWidget *parent, Renderer* renderer):
     _render_thread = NULL;
     _renderer = renderer;
 
+    _hdr_profile = colorProfileCreate();
+
     setModal(true);
     setWindowTitle(tr("Paysages 3D - Render"));
     setLayout(new QVBoxLayout());
@@ -116,6 +119,7 @@ DialogRender::~DialogRender()
 
         delete _render_thread;
     }
+    colorProfileDelete(_hdr_profile);
     delete pixbuf;
     delete pixbuf_lock;
 }

gui_qt/dialogrender.h

@@ -9,6 +9,7 @@
 #include <QLabel>
 #include <QMutex>
 #include "../lib_paysages/renderer.h"
+#include "../lib_paysages/color.h"
 
 class DialogRender : public QDialog
 {
@@ -25,6 +26,7 @@ public:
     QImage* pixbuf;
     QMutex* pixbuf_lock;
     QWidget* area;
+    ColorProfile* _hdr_profile;
 
 private slots:
     void applyRenderSize(int width, int height);

lib_paysages/atmosphere/bruneton.c

@@ -302,22 +302,6 @@ static Color _transmittanceWithShadow(double r, double mu)
     return mu < -sqrt(1.0 - (Rg / r) * (Rg / r)) ? COLOR_BLACK : _transmittance(r, mu);
 }
 
-static Color _hdr(Color c1, Color c2, Color c3)
-{
-    Color L = {c1.r + c2.r + c3.r, c1.g + c2.g + c3.g, c1.b + c2.b + c3.b, 1.0};
-
-    L.r *= exposure;
-    L.g *= exposure;
-    L.b *= exposure;
-    L.a = 1.0;
-
-    L.r = L.r < 1.413 ? pow(L.r * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.r);
-    L.g = L.g < 1.413 ? pow(L.g * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.g);
-    L.b = L.b < 1.413 ? pow(L.b * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.b);
-
-    return L;
-}
-
 static void _getMuMuSNu(double x, double y, double r, Color dhdH, double* mu, double* muS, double* nu)
 {
     double d;
@@ -1252,9 +1236,12 @@ Color brunetonGetSkyColor(AtmosphereDefinition* definition, Vector3 eye, Vector3
 
     Vector3 attenuation;
     Color inscatterColor = _getInscatterColor(&x, &t, v, s, &r, &mu, &attenuation); /* S[L]-T(x,xs)S[l]|xs */
-    Color groundColor = COLOR_BLACK;
     Color sunColor = _sunColor(x, 0.0, v, s, r, mu); /* L0 */
-    return _hdr(sunColor, groundColor, inscatterColor); /* Eq (16) */
+
+    inscatterColor.r += sunColor.r;
+    inscatterColor.g += sunColor.g;
+    inscatterColor.b += sunColor.b;
+    return inscatterColor; /* Eq (16) */
 }
 
 Color brunetonApplyAerialPerspective(Renderer* renderer, Vector3 location, Color base)
@@ -1297,6 +1284,9 @@ Color brunetonApplyAerialPerspective(Renderer* renderer, Vector3 location, Color
     Vector3 attenuation;
     Color inscatterColor = _getInscatterColor(&x, &t, v, s, &r, &mu, &attenuation); /* S[L]-T(x,xs)S[l]|xs */
     Color groundColor = _groundColor(base, x, t, v, s, r, mu, attenuation); //R[L0]+R[L*]*/
-    Color sunColor = COLOR_BLACK;
+
-    return _hdr(sunColor, groundColor, inscatterColor); /* Eq (16) */
+    groundColor.r += inscatterColor.r;
+    groundColor.g += inscatterColor.g;
+    groundColor.b += inscatterColor.b;
+    return groundColor; /* Eq (16) */
 }

lib_paysages/atmosphere/presets.c

@@ -24,34 +24,34 @@ void atmosphereAutoPreset(AtmosphereDefinition* definition, AtmospherePreset pre
             definition->model = ATMOSPHERE_MODEL_BRUNETON;
             definition->hour = 15;
             definition->minute = 0;
-            definition->dome_lighting = 0.6;
+            definition->dome_lighting = 0.2;
             break;
         case ATMOSPHERE_PRESET_CLEAR_SUNSET:
             definition->model = ATMOSPHERE_MODEL_BRUNETON;
             definition->hour = 17;
             definition->minute = 45;
-            definition->dome_lighting = 0.8;
+            definition->dome_lighting = 0.3;
             definition->sun_radius = 0.03;
             break;
         case ATMOSPHERE_PRESET_HAZY_MORNING:
             definition->model = ATMOSPHERE_MODEL_PREETHAM;
             definition->hour = 8;
             definition->minute = 30;
-            definition->dome_lighting = 0.5;
+            definition->dome_lighting = 0.25;
             definition->humidity = 0.3;
             break;
         case ATMOSPHERE_PRESET_FOGGY:
             definition->model = ATMOSPHERE_MODEL_PREETHAM;
             definition->hour = 15;
             definition->minute = 0;
-            definition->dome_lighting = 0.7;
+            definition->dome_lighting = 0.1;
             definition->humidity = 0.6;
             break;
         case ATMOSPHERE_PRESET_STORMY:
             definition->model = ATMOSPHERE_MODEL_PREETHAM;
             definition->hour = 15;
             definition->minute = 0;
-            definition->dome_lighting = 0.3;
+            definition->dome_lighting = 0.05;
             definition->humidity = 0.9;
             break;
         default:

lib_paysages/color.c

@@ -3,9 +3,12 @@
 #include <stdlib.h>
 #include <assert.h>
 #include <string.h>
+#include <math.h>
 #include "tools.h"
 #include "curve.h"
 
+/******************************** Color ********************************/
+
 Color COLOR_TRANSPARENT = {0.0, 0.0, 0.0, 0.0};
 Color COLOR_BLACK = {0.0, 0.0, 0.0, 1.0};
 Color COLOR_RED = {1.0, 0.0, 0.0, 1.0};
@@ -14,13 +17,6 @@ Color COLOR_BLUE = {0.0, 0.0, 1.0, 1.0};
 Color COLOR_WHITE = {1.0, 1.0, 1.0, 1.0};
 Color COLOR_GREY = {0.5, 0.5, 0.5, 1.0};
 
-struct ColorGradation
-{
-    Curve* red;
-    Curve* green;
-    Curve* blue;
-};
-
 void colorSave(PackStream* stream, Color* col)
 {
     packWriteDouble(stream, &col->r);
@@ -125,7 +121,20 @@ void colorMask(Color* base, Color* mask)
 
 double colorNormalize(Color* col)
 {
-    double max = colorGetValue(col);
+    if (col->r > 1.0)
+    {
+        col->r = 1.0;
+    }
+    if (col->g > 1.0)
+    {
+        col->g = 1.0;
+    }
+    if (col->b > 1.0)
+    {
+        col->b = 1.0;
+    }
+    return 1.0;
+    /*double max = colorGetValue(col);
 
     assert(max >= 0.0);
     assert(col->r >= 0.0);
@@ -139,7 +148,7 @@ double colorNormalize(Color* col)
         col->g /= max;
         col->b /= max;
     }
-    return max;
+    return max;*/
 }
 
 double colorGetValue(Color* col)
@@ -158,6 +167,96 @@ double colorGetValue(Color* col)
     return max;
 }
 
+/******************************** ColorProfile ********************************/
+struct ColorProfile
+{
+    double minvalue;
+    double maxvalue;
+};
+
+ColorProfile* colorProfileCreate()
+{
+    ColorProfile* profile;
+
+    profile = malloc(sizeof(ColorProfile));
+
+    colorProfileClear(profile);
+
+    return profile;
+}
+
+void colorProfileDelete(ColorProfile* profile)
+{
+    free(profile);
+}
+
+void colorProfileSave(PackStream* stream, ColorProfile* profile)
+{
+    /* TODO */
+}
+
+void colorProfileLoad(PackStream* stream, ColorProfile* profile)
+{
+    /* TODO */
+}
+
+void colorProfileClear(ColorProfile* profile)
+{
+    profile->minvalue = 0.0;
+    profile->maxvalue = 3.0;
+}
+
+int colorProfileCollect(ColorProfile* profile, Color pixel)
+{
+    int changed = 0;
+    double value = pixel.r + pixel.g + pixel.b;
+
+    if (value < profile->minvalue)
+    {
+        profile->minvalue = value;
+        changed = 1;
+    }
+    if (value > profile->maxvalue)
+    {
+        profile->maxvalue = value;
+        changed = 1;
+    }
+    return changed;
+}
+
+float A = 0.15;
+float B = 0.50;
+float C = 0.10;
+float D = 0.20;
+float E = 0.02;
+float F = 0.30;
+float W = 11.2;
+
+static double _uncharted2Tonemap(double x)
+{
+   return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F;
+}
+
+Color colorProfileApply(ColorProfile* profile, Color pixel)
+{
+    double exposure_bias = 2.0;
+    double white_scale = 1.0 / _uncharted2Tonemap(W);
+
+    pixel.r = pow(_uncharted2Tonemap(pixel.r * exposure_bias) * white_scale, 1.0 / 2.2);
+    pixel.g = pow(_uncharted2Tonemap(pixel.g * exposure_bias) * white_scale, 1.0 / 2.2);
+    pixel.b = pow(_uncharted2Tonemap(pixel.b * exposure_bias) * white_scale, 1.0 / 2.2);
+
+    return pixel;
+}
+
+/******************************** ColorGradation ********************************/
+struct ColorGradation
+{
+    Curve* red;
+    Curve* green;
+    Curve* blue;
+};
+
 ColorGradation* colorGradationCreate()
 {
     ColorGradation* result;

lib_paysages/color.h

@@ -2,6 +2,7 @@
 #define _PAYSAGES_COLOR_H_
 
 #include "curve.h"
+#include "pack.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -41,6 +42,19 @@ void colorMask(Color* base, Color* mask);
 double colorNormalize(Color* col);
 double colorGetValue(Color* col);
 
+/* HDR profile for tone-mapping */
+typedef struct ColorProfile ColorProfile;
+
+ColorProfile* colorProfileCreate();
+void colorProfileDelete(ColorProfile* profile);
+
+void colorProfileSave(PackStream* stream, ColorProfile* profile);
+void colorProfileLoad(PackStream* stream, ColorProfile* profile);
+
+void colorProfileClear(ColorProfile* profile);
+int colorProfileCollect(ColorProfile* profile, Color pixel);
+Color colorProfileApply(ColorProfile* profile, Color pixel);
+
 /* ColorGradation */
 typedef struct ColorGradation ColorGradation;
 

lib_paysages/render.c

@@ -6,6 +6,7 @@
 
 #include "shared/types.h"
 #include "color.h"
+#include "renderer.h"
 #include "system.h"
 
 typedef struct
@@ -589,7 +590,7 @@ void* _renderPostProcessChunk(void* data)
                 if (callback.function)
                 {
                     col = callback.function(chunk->renderer, fragment->data.location, callback.data);
-                    colorNormalize(&col);
+                    /*colorNormalize(&col);*/
                 }
                 else
                 {

lib_paysages/render.h

@@ -3,12 +3,25 @@
 
 #include <stdio.h>
 #include "shared/types.h"
-#include "renderer.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+typedef void (*RenderCallbackStart)(int width, int height, Color background);
+typedef void (*RenderCallbackDraw)(int x, int y, Color col);
+typedef void (*RenderCallbackUpdate)(double progress);
+
+typedef struct RenderArea RenderArea;
+
+typedef struct
+{
+    int width;
+    int height;
+    int antialias;
+    int quality;
+} RenderParams;
+
 void renderInit();
 void renderQuit();
 

lib_paysages/renderer.h

@@ -4,6 +4,7 @@
 #include "shared/types.h"
 #include "atmosphere/public.h"
 #include "terrain/public.h"
+#include "render.h"
 
 #ifdef __cplusplus
 extern "C" {

lib_paysages/shared/types.h

@@ -15,14 +15,6 @@ typedef struct LightStatus LightStatus;
 
 typedef Color (*f_RenderFragmentCallback)(struct Renderer* renderer, Vector3 location, void* data);
 
-typedef struct
-{
-    int width;
-    int height;
-    int antialias;
-    int quality;
-} RenderParams;
-
 typedef struct
 {
     int length;
@@ -39,12 +31,6 @@ typedef struct
     double shininess;
 } SurfaceMaterial;
 
-typedef void (*RenderCallbackStart)(int width, int height, Color background);
-typedef void (*RenderCallbackDraw)(int x, int y, Color col);
-typedef void (*RenderCallbackUpdate)(double progress);
-
-typedef struct RenderArea RenderArea;
-
 typedef struct
 {
     int hit;