¯\_(ツ)_/¯

3 files changed, 157 insertions, 31 deletions

diff --git a/engine.cpp b/engine.cpp
index 2f4fb79..7e178ff 100644
--- a/engine.cpp
+++ b/engine.cpp
@@ -1,9 +1,80 @@
 #include <iostream>
+#include <vector>
+#include <string>
+#include <cstring>
+#include <cmath>
+#include <cctype>
+#include <cassert>
 
+#include "flogo.h"
 #include "engine.h"
 
 using namespace std;
 
+bool iswordstartchar(char c){return isalpha(c)||c=='_'||c=='.'||c==':';}
+bool iswordchar(char c){return iswordstartchar(c)||isdigit(c);}
+bool isoperator(char c){return strchr("+-*/=<>()[]",c)!=NULL;}
+
+vector<string> tokenise(const char *str){
+	vector<string> tkns;
+	const char *p=str;
+	while(true){
+		while(*p&&isspace(*p))p++;
+		if(!*p)break;
+		if(*p==';'){
+			while(*p&&*p!='\n')p++;
+			continue;
+		}
+		string s;
+		if(iswordstartchar(*p)){
+			do s+=*p++;
+			while(*p&&iswordchar(*p));
+		} else if(isdigit(*p)){
+			bool havedot=false;
+			do {
+				if(*p=='.'){
+					if(!havedot)havedot=true;
+					else break;
+				} else if(!isdigit(*p))break;
+				s+=*p++;
+			} while(*p);
+		} else if(*p=='"'){
+			while(*p&&!isspace(*p))s+=*p++;
+		} else if(isoperator(*p))s+=*p++;
+		else {
+			cerr<<"UNKNOWN CHAR <"<<*p<<'>'<<endl;
+			p++;
+		}
+		tkns.push_back(move(s));
+	}
+	return tkns;
+}
+
 void logocommand(const char *str){
-	cout<<str<<endl;
+	int i;
+	vector<string> tkns=tokenise(str);
+	const int ntkns=tkns.size();
+	for(i=0;i<ntkns;i++){
+		if(tkns[i]=="forward"||tkns[i]=="fd"){
+			if(i+1>=ntkns)assert(false);
+			const int n=stoi(tkns[i+1]);
+			const int newx=turtle.x+n*sin(turtle.dir*M_PI/180),newy=turtle.y-n*cos(turtle.dir*M_PI/180);
+			drawline(turtle.x,turtle.y,newx,newy);
+			turtle.x=newx; turtle.y=newy;
+			drawturtle();
+			i++;
+		} else if(tkns[i]=="left"||tkns[i]=="lt"){
+			if(i+1>=ntkns)assert(false);
+			const int n=stoi(tkns[i+1]);
+			turtle.dir-=n;
+			drawturtle();
+			i++;
+		} else if(tkns[i]=="right"||tkns[i]=="rt"){
+			if(i+1>=ntkns)assert(false);
+			const int n=stoi(tkns[i+1]);
+			turtle.dir+=n;
+			drawturtle();
+			i++;
+		} else if(tkns[i]=="bye")exit(0);
+	}
 }
diff --git a/flogo.cpp b/flogo.cpp
index 28b754b..acb03ca 100644
--- a/flogo.cpp
+++ b/flogo.cpp
@@ -1,5 +1,9 @@
 #include <iostream>
+#include <cstdlib>
 #include <cmath>
+#include <cstdint>
+#include <cassert>
+
 #include <FL/Fl.H>
 #include <FL/Fl_Window.H>
 #include <FL/Fl_Box.H>
@@ -11,13 +15,11 @@
 #include <FL/Fl_Button.H>
 #include <FL/Fl_draw.H>
 
+#include "flogo.h"
 #include "engine.h"
 
 using namespace std;
 
-const int WIDTH=1000,HEIGHT=1000;
-
-
 Fl_Window *window;
 Fl_Scroll *drawscroll;
 Fl_Box *drawimagebox,*turtleimagebox;
@@ -28,34 +30,78 @@ Fl_Button *evaluatebutton;
 
 uchar *imagebuf,*turtlebuf;
 
+Turtle turtle;
+
 
-const uchar* someimg(void){
-	uchar *buf=new uchar[3*WIDTH*HEIGHT];
-	int x,y;
-	for(y=0;y<HEIGHT;y++){
-		for(x=0;x<WIDTH;x++){
-			buf[(WIDTH*y+x)*3+0]=(int)sqrt((999-x)*(999-x)+y*y)/100*20;
-			buf[(WIDTH*y+x)*3+1]=(int)sqrt(x*x+y*y)/100*20;
-			buf[(WIDTH*y+x)*3+2]=(int)sqrt((500-x)*(500-x)+(0-y)*(0-y))/100*20;
+void bresenham(int x1,int y1,int x2,int y2,uchar *buf,int bufintsz,int bufcellsz,uint32_t v){
+	int steep,deltax,deltay,error,ystep,x,y;
+	steep=abs(y2-y1)>abs(x2-x1);
+	if(steep){
+		swap(x1,y1);
+		swap(x2,y2);
+	}
+	if(x1>x2){
+		swap(x1,x2);
+		swap(y1,y2);
+	}
+	deltax=x2-x1;
+	deltay=abs(y2-y1);
+	error=deltax/2;
+	if(y1<y2)ystep=1; else ystep=-1;
+	for(x=x1,y=y1;x<=x2;x++){
+		if(steep){
+			switch(bufintsz){
+				case 1: buf[bufcellsz*(WIDTH*x+y)]=(uchar)v; break;
+				case 2: *(uint16_t*)(buf+bufcellsz*(WIDTH*x+y))=(uint16_t)v; break;
+				case 4: *(uint32_t*)(buf+bufcellsz*(WIDTH*x+y))=(uint32_t)v; break;
+				default: assert(false);
+			}
+		} else {
+			switch(bufintsz){
+				case 1: buf[bufcellsz*(WIDTH*y+x)]=(uchar)v; break;
+				case 2: *(uint16_t*)(buf+bufcellsz*(WIDTH*y+x))=(uint16_t)v; break;
+				case 4: *(uint32_t*)(buf+bufcellsz*(WIDTH*y+x))=(uint32_t)v; break;
+				default: assert(false);
+			}
+		}
+		error=error-deltay;
+		if(error<0){
+			y+=ystep;
+			error+=deltax;
 		}
 	}
-	return buf;
 }
 
+void drawline(int x1,int y1,int x2,int y2){
+	bresenham(x1,y1,x2,y2,imagebuf,4,4,0xff000000);
+	drawimage->uncache();
+	window->redraw();
+}
+
+void drawturtle(void){
+	memset(turtlebuf,0,WIDTH*HEIGHT*2*sizeof(uchar));
+	const double raddir=turtle.dir*M_PI/180;
+	const int x1=turtle.x-15*cos(raddir), //left-bottom
+	          y1=turtle.y-15*sin(raddir),
+	          x2=turtle.x+15*cos(raddir), //right-bottom
+	          y2=turtle.y+15*sin(raddir),
+	          x3=turtle.x+15*sin(raddir), //top
+	          y3=turtle.y-15*cos(raddir);
+	bresenham(x1,y1,x2,y2,turtlebuf+1,1,2,255);
+	bresenham(x2,y2,x3,y3,turtlebuf+1,1,2,255);
+	bresenham(x3,y3,x1,y1,turtlebuf+1,1,2,255);
+	turtleimage->uncache();
+	window->redraw();
+}
+
+
 void maincallback(Fl_Widget*,void*){
 	if(Fl::event()==FL_SHORTCUT&&Fl::event_key()==FL_Escape)return;
 	exit(0);
 }
 
-void cmdinputcallback(Fl_Widget *wid){
-	Fl_Input *inp=(Fl_Input*)wid;
-	histbrowser->insert(histbrowser->size(),inp->value());
-	histbrowser->bottomline(histbrowser->size());
-	logocommand(inp->value());
-	inp->value(NULL);
-}
-
 void evaluatebuttoncallback(Fl_Widget*){
+	if(cmdinput->value()[0]=='\0')return;
 	histbrowser->insert(histbrowser->size(),cmdinput->value());
 	histbrowser->bottomline(histbrowser->size());
 	logocommand(cmdinput->value());
@@ -69,28 +115,26 @@ void histcallback(Fl_Widget *wid){
 
 int main(int argc,char **argv){
 	window=new Fl_Window(1016,700,"FLogo");
-	Fl_Group::current(0); //manual adding to widgets
 
-	imagebuf=new uchar[WIDTH*HEIGHT*3]; //RGB
-	memset(imagebuf,255,WIDTH*HEIGHT*3*sizeof(uchar));
+	imagebuf=new uchar[WIDTH*HEIGHT*4]; //RGB(A)
+	memset(imagebuf,255,WIDTH*HEIGHT*4*sizeof(uchar));
 	turtlebuf=new uchar[WIDTH*HEIGHT*2]; //GA
 	memset(turtlebuf,0,WIDTH*HEIGHT*2*sizeof(uchar));
 
 	drawscroll=new Fl_Scroll(0,0,window->w(),window->h()-150);
 		drawimagebox=new Fl_Box(0,0,WIDTH,HEIGHT);
-			drawimage=new Fl_RGB_Image(imagebuf,WIDTH,HEIGHT);
+			drawimage=new Fl_RGB_Image(imagebuf,WIDTH,HEIGHT,4);
 			drawimagebox->image(drawimage);
-		drawscroll->add(drawimagebox);
 		turtleimagebox=new Fl_Box(0,0,WIDTH,HEIGHT);
 			turtleimage=new Fl_RGB_Image(turtlebuf,WIDTH,HEIGHT,2);
 			turtleimagebox->image(turtleimage);
-		drawscroll->add(turtleimagebox);
-	window->add(drawscroll);
+	drawscroll->end();
+	drawscroll->scroll_to(max(0,WIDTH-drawscroll->w())/2,max(0,HEIGHT-drawscroll->h())/2);
+	drawturtle();
 
 	cmdinput=new Fl_Input(0,window->h()-25,window->w()-150,25);
 		cmdinput->when(FL_WHEN_ENTER_KEY|FL_WHEN_NOT_CHANGED);
-		cmdinput->callback(cmdinputcallback);
-	window->add(cmdinput);
+		cmdinput->callback(evaluatebuttoncallback);
 
 	evaluatebutton=new Fl_Button(cmdinput->x()+cmdinput->w(),cmdinput->y(),80,cmdinput->h(),"Evaluate");
 		evaluatebutton->callback(evaluatebuttoncallback);
@@ -98,7 +142,6 @@ int main(int argc,char **argv){
 
 	histbrowser=new Fl_Select_Browser(0,drawscroll->y()+drawscroll->h(),cmdinput->w(),cmdinput->y()-(drawscroll->y()+drawscroll->h()));
 		histbrowser->callback(histcallback);
-	window->add(histbrowser);
 	histbrowser->add(""); //add blank line
 
 	window->resizable(drawscroll);
diff --git a/flogo.h b/flogo.h
new file mode 100644
index 0000000..f5b1065
--- /dev/null
+++ b/flogo.h
@@ -0,0 +1,12 @@
+#pragma once
+
+const int WIDTH=1000,HEIGHT=1000;
+
+struct Turtle{
+	double x=WIDTH/2,y=HEIGHT/2,dir=0; //dir in degrees, URDL
+};
+
+extern Turtle turtle;
+
+void drawturtle(void);
+void drawline(int x1,int y1,int x2,int y2);