A simple line extension for Sparrow

SHLine.h

//
//  SHLine.h
//  Sparrow
//
//  Created by Shilo White on 1/11/11.
//  Copyright 2011 Shilocity Productions. All rights reserved.
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the Simplified BSD License.
//

#import <Foundation/Foundation.h>
#import "SPDisplayObject.h"
#import "SPRenderSupport.h"

#import <OpenGLES/EAGL.h>
#import <OpenGLES/ES1/gl.h>
#import <OpenGLES/ES1/glext.h>

@interface SHLine : SPDisplayObject {
  @protected
	float mVertexCoords[4];
    uint mVertexColors[2];
	float mVertexAlpha[2];
	float mThickness;
}

@property (nonatomic, assign) float x2;
@property (nonatomic, assign) float y2;
@property (nonatomic, assign) uint color;
@property (nonatomic, assign) uint startColor;
@property (nonatomic, assign) uint endColor;
@property (nonatomic, assign) float startAlpha;
@property (nonatomic, assign) float endAlpha;
@property (nonatomic, assign) float thickness;

- (SHLine *)initWithSize:(float)length;
- (SHLine *)initWithLength:(float)length andThickness:(float)thickness;
- (SHLine *)initWithCoords:(float)x1 :(float)y1 :(float)x2 :(float)y2;
- (SHLine *)initWithCoords:(float)x1 :(float)y1 :(float)x2 :(float)y2 andThickness:(float)thickness;

+ (SHLine *)lineWithLength:(float)length;
+ (SHLine *)lineWithLength:(float)length andThickness:(float)thickness;
+ (SHLine *)lineWithCoords:(float)x1 :(float)y1 :(float)x2 :(float)y2;
+ (SHLine *)lineWithCoords:(float)x1 :(float)y1 :(float)x2 :(float)y2 andThickness:(float)thickness;
@end

SHLine.m

//
//  SHLine.h
//  Sparrow
//
//  Created by Shilo White on 1/11/11.
//  Copyright 2011 Shilocity Productions. All rights reserved.
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the Simplified BSD License.
//

#import "SHLine.h"

@implementation SHLine

@synthesize thickness = mThickness;

- (SHLine *)init {
	return [self initWithCoords:0:0:50.0f:0 andThickness:1.0f];
}

- (SHLine *)initWithSize:(float)length {
	return [self initWithCoords:0:0:length:0 andThickness:1.0f];
}

- (SHLine *)initWithLength:(float)length andThickness:(float)thickness {
	return [self initWithCoords:0:0:length:0 andThickness:thickness];
}

- (SHLine *)initWithCoords:(float)x1 :(float)y1 :(float)x2 :(float)y2 {
	return [self initWithCoords:x1:y1:x2:y2 andThickness:1.0f];
}

- (SHLine *)initWithCoords:(float)x1 :(float)y1 :(float)x2 :(float)y2 andThickness:(float)thickness {
	if (self = [super init]) {
		self.x = x1;
		self.y = y1;
		self.color = 0xffffff;
		mVertexCoords[2] = x2;
		mVertexCoords[3] = y2;
		mVertexAlpha[0] = 1.0f;
		mVertexAlpha[1] = 1.0f;
		mThickness = thickness;
	}
	return self;
}

+ (SHLine *)lineWithLength:(float)length {
	return [[[SHLine alloc] initWithSize:length] autorelease];
}

+ (SHLine *)lineWithLength:(float)length andThickness:(float)thickness {
	return [[[SHLine alloc] initWithLength:length andThickness:thickness] autorelease];
}

+ (SHLine *)lineWithCoords:(float)x1 :(float)y1 :(float)x2 :(float)y2 {
	return [[[SHLine alloc] initWithCoords:x1:y1:x2:y2] autorelease];
}

+ (SHLine *)lineWithCoords:(float)x1 :(float)y1 :(float)x2 :(float)y2 andThickness:(float)thickness {
	return [[[SHLine alloc] initWithCoords:x1:y1:x2:y2 andThickness:thickness] autorelease];
}

- (void)render:(SPRenderSupport *)support {
    uint colors[2];
    float alpha = self.alpha;
    
    [support bindTexture:nil];
    
	for (int i=0; i<2; i++) colors[i] = [support convertColor:mVertexColors[i] alpha:mVertexAlpha[i]*alpha];
	
    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_COLOR_ARRAY);    
    
	glVertexPointer(2, GL_FLOAT, 0, mVertexCoords);
	glColorPointer(4, GL_UNSIGNED_BYTE, 0, colors);
	glLineWidth(mThickness);
	glDrawArrays(GL_LINES, 0, 2);
    
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_COLOR_ARRAY);
}

- (SPRectangle *)boundsInSpace:(SPDisplayObject *)targetCoordinateSpace
{
    if (targetCoordinateSpace == self)
        return [SPRectangle rectangleWithX:0 y:0 width:mVertexCoords[2] height:mVertexCoords[3]];
    
    SPMatrix *transformationMatrix = [self transformationMatrixToSpace:targetCoordinateSpace];
    SPPoint *point = [[SPPoint alloc] init];
    
    float minX = FLT_MAX, maxX = -FLT_MAX, minY = FLT_MAX, maxY = -FLT_MAX;
    for (int i=0; i<2; i++) {
        point.x = mVertexCoords[2*i];
        point.y = mVertexCoords[2*i+1];
        SPPoint *transformedPoint = [transformationMatrix transformPoint:point];
        float tfX = transformedPoint.x; 
        float tfY = transformedPoint.y;
        minX = MIN(minX, tfX);
        maxX = MAX(maxX, tfX);
        minY = MIN(minY, tfY);
        maxY = MAX(maxY, tfY);
    }
    [point release];
    return [SPRectangle rectangleWithX:minX y:minY width:maxX-minX height:maxY-minY];    
}

- (void)setX2:(float)x2 {
	mVertexCoords[2] = x2;
}

- (void)setY2:(float)y2 {
	mVertexCoords[3] = y2;
}

- (void)setColor:(uint)color {
    for (int i=0; i<2; i++) {
		mVertexColors[i] = color;
	}
}

- (void)setStartColor:(uint)color {
	mVertexColors[0] = color;
}

- (void)setEndColor:(uint)color {
	mVertexColors[1] = color;
}

- (void)setStartAlpha:(float)alpha {
	if (alpha < 0) alpha = 0;
	if (alpha > 1.0f) alpha = 1.0f;
	
	mVertexAlpha[0] = alpha;
}

- (void)setEndAlpha:(float)alpha {
	if (alpha < 0) alpha = 0;
	if (alpha > 1.0f) alpha = 1.0f;
	
	mVertexAlpha[1] = alpha;
}

- (float)x2 {
	return mVertexCoords[2];
}

- (float)y2 {
	return mVertexCoords[3];
}

- (uint)color {
	return mVertexColors[0];
}

- (uint)startColor {
	return mVertexColors[0];
}

- (uint)endColor {
	return mVertexColors[1];
}

- (float)startAlpha {
	return mVertexAlpha[0];
}

- (float)endAlpha {
	return mVertexAlpha[1];
}
@end

Hello. I believe my code was meant for the last two arguments to be width and height for the line. So the end coordinate would be relative to the start of the line, rather then relative to the stage. I could be wrong, thanks for the heads up though.

…

Sent from my iPhone

On Jan 3, 2012, at 5:35 AM, ***@***.*** wrote: I found a problem with SHLine, shown in example below: SHLine *line = [SHLine lineWithCoords:10 :10 :150 :150]; [self addChild:line]; This will draw line from (10, 10) to (160, 160) because of this lines: mVertexCoords[2] = x2; mVertexCoords[3] = y2; It should be: mVertexCoords[2] = x2 - x1; mVertexCoords[3] = y2 - y1; --- Reply to this email directly or view it on GitHub: https://gist.github.com/870169