viewport rotation

binding-mri/viewport-binding.cpp

@@ -80,6 +80,7 @@ DEF_PROP_I(Viewport, OY)
 
 DEF_PROP_F(Viewport, ScaleX)
 DEF_PROP_F(Viewport, ScaleY)
+DEF_PROP_F(Viewport, Rotation)
 
 void viewportBindingInit(){
 	VALUE klass = rb_define_class("Viewport", rb_cObject);
@@ -96,6 +97,7 @@ void viewportBindingInit(){
 	INIT_PROP_BIND( Viewport, OY,       "oy"      );
 	INIT_PROP_BIND( Viewport, ScaleX,   "scale_x" );
 	INIT_PROP_BIND( Viewport, ScaleY,   "scale_y" );
+	INIT_PROP_BIND( Viewport, Rotation, "rotation");
 	INIT_PROP_BIND( Viewport, Color,    "color"   );
 	INIT_PROP_BIND( Viewport, Tone,     "tone"    );
 }

src/sprite.cpp

@@ -623,10 +623,14 @@ void Sprite::onGeometryChange(const Scene::Geometry &geo){
 	 * relative to screen origin */
 	p->trans.setGlobalOffset(geo.offset());
 	Viewport* viewport = ViewportElement::getViewport();
-	if (viewport)
+	if (viewport) {
 		p->trans.setGlobalScale(Vec2(viewport->getScaleX(), viewport->getScaleY()));
-	else
+		p->trans.setGlobalRotation(viewport->getRotation());
+	}
+	else {
 		p->trans.setGlobalScale(Vec2(1.0, 1.0));
+		p->trans.setGlobalRotation(0);
+	}
 
 	p->sceneRect.setSize(geo.rect.size());
 	p->sceneOrig = geo.orig;

src/transform.h

@@ -43,15 +43,17 @@
 //
 ////////////////////////////////////////////////////////////
 
+// added global rotation and global scale, modified updateMatrix(), using SDL funcs instead of math.h
 
 #ifndef TRANSFORM_H
 #define TRANSFORM_H
 
 #include "etc-internal.h"
 
-#include <math.h>
 #include <SDL3/SDL_stdinc.h>
 
+constexpr float PI = 3.14159265358979323846f;
+
 class Transform{
 public:
 	Transform()
@@ -68,7 +70,9 @@ public:
 	Vec2 &getPosition()       { return position;       }
 	Vec2 &getOrigin()         { return origin;         }
 	Vec2 &getScale()          { return scale;          }
+	Vec2 &getGlobalScale()    { return globalScale;    }
 	float getRotation()       { return rotation;       }
+	float getGlobalRotation() { return globalRotation; }
 
 	Vec2i getPositionI() const{
 		return Vec2i(position.x, position.y);
@@ -98,6 +102,11 @@ public:
 		dirty = true;
 	}
 
+	void setGlobalRotation(float value){
+		globalRotation = value;
+		dirty = true;
+	}
+
 	void setGlobalOffset(const Vec2i &value){
 		offset = value;
 		dirty = true;
@@ -121,23 +130,54 @@ private:
 	void updateMatrix(){
     	if (rotation >= 360 || rotation < -360)
     	    rotation = (float)SDL_fmod(rotation, 360);
-		if (rotation < 0)
-			rotation += 360;
 		
-		float angle  = rotation * 3.141592654f / 180.0f;
+    	if (globalRotation >= 360 || globalRotation < -360)
-		float cosine = (float) SDL_cos(angle);
+    	    globalRotation = (float)SDL_fmod(globalRotation, 360);
-		float sine   = (float) SDL_sin(angle);
+		
+    	// object rotation cos and sin
+    	float angle = rotation * PI / 180.0f;
+    	float cosine = SDL_cos(angle);
+    	float sine   = SDL_sin(angle);
+		
     	float sxc = scale.x * cosine;
     	float syc = scale.y * cosine;
     	float sxs = scale.x * sine;
     	float sys = scale.y * sine;
-		float tx     = (-origin.x * sxc - origin.y * sys + position.x) * globalScale.x + offset.x;
-		float ty     = ( origin.x * sxs - origin.y * syc + position.y) * globalScale.y + offset.y;
 		
-		matrix[0]  =  sxc * globalScale.x;
+    	// object matrix
-		matrix[1]  = -sxs * globalScale.y;
+    	float a =  sxc * globalScale.x;
-		matrix[4]  =  sys * globalScale.x;
+    	float b = -sxs * globalScale.y;
-		matrix[5]  =  syc * globalScale.y;
+    	float c =  sys * globalScale.x;
+    	float d =  syc * globalScale.y;
+		
+    	float tx = (-origin.x * sxc - origin.y * sys + position.x)
+    	         * globalScale.x;
+		
+    	float ty = ( origin.x * sxs - origin.y * syc + position.y)
+    	         * globalScale.y;
+		
+    	// viewport rotation cos and sin
+    	float globalAngle = globalRotation * PI / 180.0f;
+    	float gc = SDL_cos(globalAngle);
+    	float gs = SDL_sin(globalAngle);
+		
+    	// basis rotation
+    	float na = a * gc - b * gs;
+    	float nb = a * gs + b * gc;
+    	float nc = c * gc - d * gs;
+    	float nd = c * gs + d * gc;
+		
+    	float dx = tx;
+    	float dy = ty;
+		
+		// appling global rotation
+    	tx = dx * gc - dy * gs + offset.x;
+    	ty = dx * gs + dy * gc + offset.y;
+		
+    	matrix[0]  = na;
+    	matrix[1]  = nb;
+    	matrix[4]  = nc;
+    	matrix[5]  = nd;
     	matrix[12] = tx;
     	matrix[13] = ty;
 	}
@@ -146,6 +186,7 @@ private:
 	Vec2 origin;
 	Vec2 scale;
 	float rotation;
+	float globalRotation;
 
 	/* Silently added to position */
 	Vec2i offset;

src/viewport.cpp

@@ -46,6 +46,7 @@ struct ViewportPrivate{
 
 	double scaleX;
 	double scaleY;
+	double rotation;
 
 	EtcTemps tmp;
 
@@ -56,6 +57,7 @@ struct ViewportPrivate{
 	      tone(&tmp.tone),
 	      scaleX(1.0),
 	      scaleY(1.0),
+	      rotation(0.0),
 	      isOnScreen(false)
 	{
 		rect->set(x, y, width, height);
@@ -141,6 +143,7 @@ DEF_ATTR_RD_SIMPLE(Viewport, OY, int, geometry.orig.y)
 
 DEF_ATTR_RD_SIMPLE(Viewport, ScaleX,   double, p->scaleX)
 DEF_ATTR_RD_SIMPLE(Viewport, ScaleY,   double, p->scaleY)
+DEF_ATTR_RD_SIMPLE(Viewport, Rotation, double, p->rotation)
 
 DEF_ATTR_SIMPLE(Viewport, Rect,  Rect&,  *p->rect)
 DEF_ATTR_SIMPLE(Viewport, Color, Color&, *p->color)
@@ -186,6 +189,16 @@ void Viewport::setScaleY(double value){
 	notifyGeometryChange();
 }
 
+void Viewport::setRotation(double value){
+	guardDisposed();
+
+	if (p->rotation == value)
+		return;
+
+	p->rotation = value;
+	notifyGeometryChange();
+}
+
 void Viewport::initDynAttribs(){
 	p->rect = new Rect(*p->rect);
 	p->color = new Color;

src/viewport.h

@@ -43,6 +43,7 @@ public:
 	DECL_ATTR( OY,       int    )
 	DECL_ATTR( ScaleX,   double )
 	DECL_ATTR( ScaleY,   double )
+	DECL_ATTR( Rotation, double )
 	DECL_ATTR( Color,    Color& )
 	DECL_ATTR( Tone,     Tone&  )