Change camera right default length to output image aspect ratio.

Author: c-lipka

changes.txt

@@ -32,6 +32,8 @@ should be located in the same directory as this file is.
 Changes between v3.7.1-rc.1 and v3.8.0-???
 ==========================================
 
+This version is still under active development, and not finalized yet.
+
 NOTE: This release cycle has been redesignated v3.8.0. There will not be a
 v3.7.1 release proper.
 
@@ -48,6 +50,11 @@ Changed Behaviour
   - Any new behaviour formerly activated by `#version 3.71` now requires
     `#version 3.8` (or higher); specifying `#version 3.71` will trigger a
     corresponding warning.
+  - Some defaults have been changed (requires `#version 3.8` as the _very first_
+    statement of the scene, or a corresponding command line / INI setting):
+      - `ambient` now defaults to 0.0 instead of 0.1.
+      - Camera `right` vector length now defaults to the output image aspect
+        ratio (presuming square pixels) instead of 1.33.
 
 Other Noteworthy
 ----------------

source/backend/control/scene.cpp

@@ -99,6 +99,10 @@ void Scene::StartParser(POVMS_Object& parseOptions)
     sceneData->inputFile = parseOptions.TryGetUCS2String(kPOVAttrib_InputFile, "object.pov");
     sceneData->headerFile = parseOptions.TryGetUCS2String(kPOVAttrib_IncludeHeader, "");
 
+    DBL outputWidth  = parseOptions.TryGetFloat(kPOVAttrib_Width, 160);
+    DBL outputHeight = parseOptions.TryGetFloat(kPOVAttrib_Height, 120);
+    sceneData->aspectRatio = outputWidth / outputHeight;
+
     sceneData->defaultFileType = parseOptions.TryGetInt(kPOVAttrib_OutputFileType, DEFAULT_OUTPUT_FORMAT); // TODO - should get DEFAULT_OUTPUT_FORMAT from the front-end
     sceneData->clocklessAnimation = parseOptions.TryGetBool(kPOVAttrib_ClocklessAnimation, false); // TODO - experimental code
 

source/core/scene/scenedata.h

@@ -70,7 +70,7 @@ struct Skysphere_Struct;
 /// This class just provides access to scene specific data
 /// needed in many parts of the code. Be aware that while most
 /// data is members are public, they shall **not** be modified
-/// carelessly. Code from POV-Ray 3.6 and earlier does depend
+/// carelessly. Code from POV-Ray v3.6 and earlier does depend
 /// on simple access of this data all over the old code, so
 /// this provides an efficient way to reuse all the old code.
 /// By no means shall this way of data access be used for any
@@ -166,7 +166,7 @@ class SceneData
         bool realTimeRaytracing;
 
         // ********************************************************************************
-        // Old globals from 3.6 and earlier are temporarily kept below. Please carefully
+        // Old globals from v3.6 and earlier are temporarily kept below. Please carefully
         // consider what is added and mark it accordingly if it needs to go away again
         // prior to final release! [trf]
         // ********************************************************************************
@@ -196,6 +196,9 @@ class SceneData
         UCS2String inputFile; // TODO - handle differently
         UCS2String headerFile;
 
+        /// Aspect ratio of the output image.
+        DBL aspectRatio;
+
         int defaultFileType;
 
         FrameSettings frameSettings; // TODO - move ???
@@ -227,13 +230,13 @@ class SceneData
 
         /// Convenience function to determine the effective SDL version.
         ///
-        /// Given that version 3.7 and later require the first statement in the file to be
+        /// Given that version v3.7 and later require the first statement in the file to be
         /// a `#version` statement, the absence of such a statement can be presumed to
-        /// indicate a pre-3.7 scene; this function assumes version 3.62 in that case
-        /// (which was the latest 3.6 version when 3.7.0 was released).
+        /// indicate a pre-v3.7 scene; this function assumes v3.6.2 in that case
+        /// (which was the latest version before v3.7.0).
         /// @note       It is recommended to use this function only where behaviour differs
-        ///             significantly from pre-3.7 versions.
-        /// @return     The current language version in integer format (e.g. 370 for 3.70)
+        ///             significantly from pre-v3.7 versions.
+        /// @return     The current language version in integer format (e.g. 370 for v3.7.0)
         ///             if explicitly specified, or 362 otherwise.
         ///
         inline unsigned int EffectiveLanguageVersion() const

source/parser/parser.cpp

@@ -184,12 +184,9 @@ void Parser::Run()
         Default_Texture->Pigment = Create_Pigment();
         Default_Texture->Tnormal = NULL;
         Default_Texture->Finish  = Create_Finish();
-        // [JG] If the version has been *explictly* set in the ini or command line,
-        // override the default ambient (rgb 0.1) (in Create_Finish) to 0.0
-        if ((sceneData->languageVersionSet) && (sceneData->languageVersion >= 380))
-        {
-            Default_Texture->Finish->Ambient.Clear();
-        }
+
+        // Initialize various defaults depending on language version as per command line / INI settings.
+        InitDefaults(sceneData->EffectiveLanguageVersion());
 
         Not_In_Default = true;
         Ok_To_Declare = true;
@@ -513,6 +510,34 @@ void Parser::Frame_Init()
 }
 
 
+/****************************************************************************/
+
+void Parser::InitDefaults(int version)
+{
+    // Initialize defaults depending on version:
+    // As of v3.8...
+    //   - `ambient` defaults to 0.0.
+    //   - Camera `right` length defaults to output image aspect ratio.
+    // Prior to that...
+    //   - `ambient` defaulted to 0.1.
+    //   - Camera `right` length defaulted to 1.33.
+
+    double ambientLevel;
+    double rightLength;
+    if (version >= 380)
+    {
+        ambientLevel = 0.0;
+        rightLength = sceneData->aspectRatio;
+    }
+    else
+    {
+        ambientLevel = 0.1;
+        rightLength = 1.33;
+    }
+    Default_Texture->Finish->Ambient = MathColour(ambientLevel);
+    Default_Camera.Right = Vector3d(rightLength, 0.0, 0.0);
+}
+
 
 /*****************************************************************************
 *
@@ -4883,7 +4908,6 @@ TEXTURE *Parser::Parse_Mesh_Texture (TEXTURE **t2, TEXTURE **t3)
 
 ObjectPtr Parser::Parse_Ovus()
 {
-    DBL distance;
     Ovus *Object;
 
     Parse_Begin();

source/parser/parser.h

@@ -633,6 +633,7 @@ class Parser : public SceneTask
 
         // parse.h/parse.cpp
         void Frame_Init(void);
+        void InitDefaults(int version);
         void Parse_Coeffs(int order, DBL *Coeffs);
 
         ObjectPtr Parse_Bicubic_Patch(void);

source/parser/parser_expressions.cpp

@@ -1040,7 +1040,7 @@ void Parser::Parse_Num_Factor (EXPRESS& Express,int *Terms)
                     if (!parsingVersionDirective)
                     {
                         // Normally, the `version` pseudo-variable needs to return the effective language version
-                        // (which now defaults to 3.6.2) so that include files can properly switch back after
+                        // (which now defaults to v3.6.2) so that include files can properly switch back after
                         // temporarily overriding the `#version` setting.
                         Val = sceneData->EffectiveLanguageVersion() / 100.0;
                     }
@@ -2661,7 +2661,7 @@ void Parser::Parse_Colour (RGBFTColour& colour, bool expectFT)
                 // Note: Setting up for potential warning on single value float promote to
                 // five value color vector. Any single float will be promoted to the full
                 // 'tgtTerms' value. This usually results in filter and trasmit values >0,
-                // which caused shadow artifacts back to at least version 3.6.1.
+                // which caused shadow artifacts back to at least version v3.6.1.
                 if ((Token.Token_Id==FLOAT_FUNCT_TOKEN) || (Token.Token_Id==FUNCT_ID_TOKEN))
                     sawFloatOrFloatFnct = true;
                 else

source/parser/parser_tokenizer.cpp

@@ -2432,10 +2432,12 @@ void Parser::Parse_Directive(int After_Hash)
                                           "statement in the scene file. If your scene will adapt to whatever version "
                                           "is in use dynamically, start your scene with '#version version'.");
                             }
-                            else if ((!sceneData->languageVersionSet) && (sceneData->languageVersion >= 380))
-                            {// [JG] first item, not languageVersionLate : override the default ambient (rgb 0.1) (in Create_Finish) for 0.0
-                             // Do not bother to create a copy, it has not been used yet
-                                Default_Texture->Finish->Ambient.Clear();
+
+                            if (!sceneData->languageVersionLate && !sceneData->languageVersionSet)
+                            {
+                                // Got `#version` as the first statement of the file.
+                                // Initialize various defaults depending on language version specified.
+                                InitDefaults(sceneData->languageVersion);
                             }
 
                             // NB: This must be set _after_ parsing the value, in order for the `#version version`