I am trying to find my way using SVGKit (https://github.com/SVGKit/SVGKit) for an iOS project dealing with geographical maps.
At this point, I can access a particular area on a map using a CALayer object. That lets me access the rectangle surrounding the area.
Here is the code I use for this:
CALayer *layer=[svgView.document layerWithIdentifier:#"myLayerID"];
[layer setBackgroundColor:[UIColor orangeColor].CGColor];
if( [layer isKindOfClass:[CAShapeLayer class]] )
{
CAShapeLayer* shapeLayer = (CAShapeLayer*) layer;
NSLog(#"That is good so far!");
layer.mask=shapeLayer;
}
But I need to access the precise area of the map; not only the surrounding rectangle, in order to highlight it.
I have kind of read I should use the CGPathRef and a mask.
How exactly can I do this?
Thanks for any tip.
When you find the CALayer, cast it to a CAShapeLayer (if you can; if you have the right layer, this should work fine).
if( [layer isKindOfClass:[CAShapeLayer class]] )
{
CAShapeLayer* shapeLayer = (CAShapeLayer*) layer;
// Now you have access to lots more Apple methods
}
Then you can chnage the line width, fill color, etc - all sorts of funky stuff.
Also look into CALayer.shadow* - various features from Apple there that will automatically hilight the visible parts of a layer.
Related
I am analysing solar farms and have defined two areas of geometry. In the example below, for a site called 'Stateline', I have drawn the boundary of the site and saved the geometry as a variable 'Stateline_boundary'. I have drawn around the solar panels within the boundary, which exist in two distinct groups and saved the geometry as a variable 'Stateline_panels'.
Stateline_panels has two co-ordinate lists (as there are two areas of panels).
When I try to subtract the area covered by the panels from the area within the boundary only the first of the two lists in the 'Stateline_panels' geometry is used (see code below and attached image).
var mask = Stateline_boundary
var mask_no_panels = mask.difference(Stateline_panels);
Map.addLayer(mask_no_panels,{},'Stateline_mask_no_panels',false);
I don't understand the behaviour of the geometry. Specifically why when adding the 'Stateline_panels' geometry to the map it displays in its entirety, but when used as a mask breaks the geometry and only uses the first of two lists of coordinates.
I was going to write a longer question asking why the geometry variables seem to behave differently when they are imported into the script rather than listed within the script (which I don't think should make a difference, but it does). However I think this is an earlier manifestation of whatever is going on.
The methodology that I found worked in the end was to create geometry assets individually with the polygon tool in the Earth Engine IDE - ensuring that each is on a different layer (using the line tool, then converting to polygons never worked).
Not only was this more flexible, it was also easier to manage on Earth Engine as editing geometries is not easy. I read about the importance of winding clockwise - though never determined if that was part of the issue here. If I always drew polygons clockwise the issue never occured.
I ended up with my aoi covered in polygons like this (each colour a different named layer/geometry object):
Once this was done, manipulating each geometry object in the code editor was relatively straightforward. They can be converted to FeatureCollections and merged (or subtracted) using simple code - see below for my final code.
It was also then easy to share them between scripts by importing the generated code.
I hope that helps someone - first attempt at answering a question (even if its my own). :)
// Convert panel geometries to Feature Collections and merge to create one object.
var spw = ee.FeatureCollection(stateline_panels_west);
var spe = ee.FeatureCollection(stateline_panels_east);
var stateline_panels = spw.merge(spe);
// Convert 'features to mask' geometries to Feature Collections.
var gc = ee.FeatureCollection(golf_course);
var sp = ee.FeatureCollection(salt_pan);
var sc = ee.FeatureCollection(solar_concentrator);
var h1 = ee.FeatureCollection(hill_1);
var h2 = ee.FeatureCollection(hill_2);
var h3 = ee.FeatureCollection(hill_3);
var mf = ee.FeatureCollection(misc_features);
// Merge geometries to create mask
var features_to_mask = gc.merge(sp).merge(sc).merge(h1).merge(h2).merge(h3).merge(mf);
// Convert 'Features_to_mask' to geometry (needed to create mask)
var features_to_mask = features_to_mask.geometry();
// Change name
var mask = features_to_mask
///// If site has other solar panels nearby need to add these separately & buffer by 1km
var extra_mask = ee.Feature(solar_concentrator);
var extra_mask = extra_mask.buffer(1000);
var extra_mask = extra_mask.geometry();
///// Join mask & extra mask into single feature using .union()
// Geometry objects
var mask = mask.union(extra_mask);
I've been struggling with this issue off and on for the better part of a year.
As the title says, i wish to dimension from one side of a wall, to both sides of openings (door openings), then terminate at the other end of the wall (vertically and horizontally). I also wish to dimension to all families hosted in the wall, but i have been able to accomplish this using ScottWilson's voodo magic helper class. Found Here: http://thebuildingcoder.typepad.com/blog/2016/04/stable-reference-string-magic-voodoo.html
foreach (ElementId ele in selSet) {
FamilyInstance fi = doc.GetElement(ele) as FamilyInstance;
Reference reference = ScottWilsonVoodooMagic.GetSpecialFamilyReference(fi,ScottWilsonVoodooMagic.SpecialReferenceType.CenterLR,doc);
refs.Append(reference);
pts[i] = ( fi.Location as LocationPoint ).Point;
i++;
}
XYZ offset = new XYZ(0,0,4);
Line line = Line.CreateBound( pts[0]+offset, pts[selSet.Count - 1]+offset );
using( Transaction t = new Transaction( doc ) )
{
t.Start( "dimension embeds" );
Dimension dim = doc.Create.NewDimension(doc.ActiveView, line, refs );
t.Commit();
}
The problem lies in determining the appropriate stable references to the wall faces. I am able to find all faces on a wall, but this gives me 100+ faces to sort through.
If anyone can help me it would be greatly appreciated!
Side note: The closest of gotten is using a casting a ray trace through my panel, then using a reference intersector method to determine references. But i'm really struggling with implementation: http://thebuildingcoder.typepad.com/blog/2015/12/retrieving-wall-openings-and-sorting-points.html
These two posts should provide more than enough to solve all your issues:
Dimension walls by iterating their faces
Dimension walls by shooting a ray
Basically, you need to obtain references to the faces or edges that you wish to attach the dimensioning to. These references can be obtained in several ways. Two common and easy approaches are:
Retrieve the element geometry using the option ComputeReferences set to true and extract the specific face required.
Shoot a ray through the model to determine the required element and its face using the 2017
ReferenceIntersector Class.
I have an view that have mutiples views inside it, and an image presentation (aka. 'cover flow') into that too... And I need to make a screenshot programatically !
Since docs says that "renderInContext:" will not render 3d animations :
"Important The Mac OS X v10.5 implementation of this method does not support the entire Core Animation composition model. QCCompositionLayer, CAOpenGLLayer, and QTMovieLayer layers are not rendered. Additionally, layers that use 3D transforms are not rendered, nor are layers that specify backgroundFilters, filters, compositingFilter, or a mask values. Future versions of Mac OS X may add support for rendering these layers and properties."
source: https://developer.apple.com/library/mac/#documentation/graphicsimaging/reference/CALayer_class/Introduction/Introduction.html
I have searched a lot, and my 'best' solution (that is not good at all), is to create my own CGContext and record all CG animations into it. But I really do not want to do it, because I will need to re-write most of my animations codes and it will be very expensive for memory... I found other solutions (some of then unmakable) as use openGL or capture through AVSessions, but no one that can help me...
What are my options ? Any with that problem ?
Thanks for your time !
have you actually tried it? I'm currently working on a project with several 3D transforms, and when I try to programmatically make this screenshot it works just fine :)
Here is the code I use:
-(UIImage *)getScreenshot
{
CGFloat scale = 1.0;
if([[UIScreen mainScreen]respondsToSelector:#selector(scale)])
{
CGFloat tmp = [[UIScreen mainScreen]scale];
if (tmp > 1.5)
{
scale = 2.0;
}
}
if(scale > 1.5)
{
UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, scale);
}
else
{
UIGraphicsBeginImageContext(self.frame.size);
}
//SELF HERE IS A UIVIEW
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return screenshot;
}
I got it working with protocols.... I'm implementing a protocol in all UIViews classes that make 3D transforms. So when I request a screenshot, it make all subviews screenshot, and generate one UIImage.. Not so good for lots of views, but I'm doing in a few views.
#pragma mark - Protocol implementation 'TDITransitionCustomTransform'
//Conforms to "TDITransitionCustomTransform" protocol, return currrent image view state , by current layer
- (UIImage*)imageForCurrentState {
//Make print
UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, 0.0);
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//return printed image
return screenShot;
}
I was thinking it may works now because I'm doing that render in the transformed view layer, which have being transformed it self...
And it wasn't working because "renderInContext:" doesn't get layers of it subviews, may it possible ?
Anyone interest in a bit more code of this solution, can be found here . in the apple dev forum.
It may be a function bug, or it just not being design for this purpose ...
May Be You can use Core Graphaic instead of CATransform3DMakeRotation ：）
CGAffineTransform flip = CGAffineTransformMakeScale(1.0, -1.0);
Which get effet on the renderInContext
I've been converting my own personal OGLES 2.0 framework to take advantage of the functionality added by the new iOS 5 framework GLKit.
After pleasing results, I now wish to implement the colour-based picking mechanism described here. For this, you must access the back buffer to retrieve a touched pixel RGBA value, which is then used as a unique identifier for a vertex/primitive/display object. Of course, this requires temporary unique coloring of all vertices/primitives/display objects.
I have two questions, and I'd be very grateful for assistance with either:
I have access to a GLKViewController, GLKView, CAEAGLLayer (of the GLKView) and an EAGLContext. I also have access to all OGLES 2.0
buffer related commands. How do I combine these to identify the color
of a pixel in the EAGLContext I'm tapping on-screen?
Given that I'm using Vertex Buffer Objects to do my rendering, is there a neat way to override the colour provided to my vertex shader
which firstly doesn't involve modifying buffered vertex (colour)
attributes, and secondly doesn't involve the addition of an IF
statement into the vertex shader?
I assume the answer to (2) is "no", but for reasons of performance and non-arduous code revamping I thought it wise to check with someone more experienced.
Any suggestions would be gratefully received. Thank you for your time
UPDATE
Well I now know how to read pixel data from the active frame buffer using glReadPixels. So I guess I just have to do the special "unique colours" render to the back buffer, briefly switch to it and read pixels, then switch back. This will inevitably create a visual flicker, but I guess it's the easiest way; certainly quicker (and more sensible) than creating a CGImageContextRef from a screen snapshot and analyzing that way.
Still, any tips as regards the back buffer would be much appreciated.
Well, I've worked out exactly how to do this as concisely as possible. Below I explain how to achieve this and list all the code required :)
In order to allow touch interaction to select a pixel, first add a UITapGestureRecognizer to your GLKViewController subclass (assuming you want tap-to-select-pixel), with the following target method inside that class. You must make your GLKViewController subclass a UIGestureRecognizerDelegate:
#interface GLViewController : GLKViewController <GLKViewDelegate, UIGestureRecognizerDelegate>
After instantiating your gesture recognizer, add it to the view property (which in GLKViewController is actually a GLKView):
// Inside GLKViewController subclass init/awakeFromNib:
[[self view] addGestureRecognizer:[self tapRecognizer]];
[[self tapRecognizer] setDelegate:self];
Set the target action for your gesture recognizer; you can do this when creating it using a particular init... however I created mine using Storyboard (aka "the new Interface Builder in Xcode 4.2") and wired it up that way.
Anyway, here's my target action for the tap gesture recognizer:
-(IBAction)onTapGesture:(UIGestureRecognizer*)recognizer {
const CGPoint loc = [recognizer locationInView:[self view]];
[self pickAtX:loc.x Y:loc.y];
}
The pick method called in there is one I've defined inside my GLKViewController subclass:
-(void)pickAtX:(GLuint)x Y:(GLuint)y {
GLKView *glkView = (GLKView*)[self view];
UIImage *snapshot = [glkView snapshot];
[snapshot pickPixelAtX:x Y:y];
}
This takes advantage of a handy new method snapshot that Apple kindly included in GLKView to produce a UIImage from the underlying EAGLContext.
What's important to note is a comment in the snapshot API documentation, which states:
This method should be called whenever your application explicitly
needs the contents of the view; never attempt to directly read the
contents of the underlying framebuffer using OpenGL ES functions.
This gave me a clue as to why my earlier attempts to invoke glReadPixels in attempts to access pixel data generated an EXC_BAD_ACCESS, and the indicator that sent me down the right path instead.
You'll notice in my pickAtX:Y: method defined a moment ago I call a pickPixelAtX:Y: on the UIImage. This is a method I added to UIImage in a custom category:
#interface UIImage (NDBExtensions)
-(void)pickPixelAtX:(NSUInteger)x Y:(NSUInteger)y;
#end
Here is the implementation; it's the final code listing required. The code came from this question and has been amended according to the answer received there:
#implementation UIImage (NDBExtensions)
- (void)pickPixelAtX:(NSUInteger)x Y:(NSUInteger)y {
CGImageRef cgImage = [self CGImage];
size_t width = CGImageGetWidth(cgImage);
size_t height = CGImageGetHeight(cgImage);
if ((x < width) && (y < height))
{
CGDataProviderRef provider = CGImageGetDataProvider(cgImage);
CFDataRef bitmapData = CGDataProviderCopyData(provider);
const UInt8* data = CFDataGetBytePtr(bitmapData);
size_t offset = ((width * y) + x) * 4;
UInt8 b = data[offset+0];
UInt8 g = data[offset+1];
UInt8 r = data[offset+2];
UInt8 a = data[offset+3];
CFRelease(bitmapData);
NSLog(#"R:%i G:%i B:%i A:%i",r,g,b,a);
}
}
#end
I originally tried some related code found in an Apple API doc entitled: "Getting the pixel data from a CGImage context" which required 2 method definitions instead of this 1, but much more code is required and there is data of type void * for which I was unable to implement the correct interpretation.
That's it! Add this code to your project, then upon tapping a pixel it will output it in the form:
R:24 G:46 B:244 A:255
Of course, you should write some means of extracting those RGBA int values (which will be in the range 0 - 255) and using them however you want. One approach is to return a UIColor from the above method, instantiated like so:
UIColor *color = [UIColor colorWithRed:red/255.0f green:green/255.0f blue:blue/255.0f alpha:alpha/255.0f];
I've recently started learning HLSL after deciding that I wanted better lighting than what BasicEffect offered. After going through many tutorials, I found this and decided to learn from it:
http://brooknovak.wordpress.com/2008/11/13/hlsl-per-pixel-point-light-using-phong-blinn-lighting-model/
It seems that the shader above doesn't work very well in my game though, because my game uses a tile based approach, which means multiple models in a grid-like formation.
What happens is that each of my tiles gets shaded separately from the others. Please see this image for a visual reference:
http://i.imgur.com/1Sfi2.png
I understand that this is because each tile has it's own model and the shader doesn't take into account other models as it's executing on the meshes of a model.
Now, for the question. How does one go about to shade all the tiles together? I understand that I may have to write a shader from scratch to accomplish this, but if anyone could give me some tips on how to achieve the effect I want, I'd really appreciate it.
It's late so there's a possibility that I've forgotten something. If you need more information, please tell me and I'll add it.
Thanks, Merigrim
EDIT:
Here is my code for drawing a model:
public void DrawModel(Model model, Matrix modelTransform, Matrix[] absoluteBoneTransforms, Vector3 color, float alpha = 1.0f, Texture2D texture = null)
{
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
{
foreach (ModelMesh mesh in model.Meshes)
{
foreach (ModelMeshPart part in mesh.MeshParts)
{
part.Effect = effect;
Matrix world = absoluteBoneTransforms[mesh.ParentBone.Index] * modelTransform;
effect.Parameters["World"].SetValue(absoluteBoneTransforms[mesh.ParentBone.Index] * modelTransform);
effect.Parameters["View"].SetValue(camera.view);
effect.Parameters["Projection"].SetValue(camera.projection);
effect.Parameters["CameraPos"].SetValue(camera.cameraPosition);
Vector3 lookAt = camera.cameraPosition + camera.cameraDirection;
effect.Parameters["LightPosition"].SetValue(new Vector3(lookAt.X, 1.0f, lookAt.Z - 5.0f));
effect.Parameters["LightDiffuseColor"].SetValue(new Vector3(0.45f, 0.45f, 0.45f));
effect.Parameters["LightSpecularColor"].SetValue(new Vector3(0.45f, 0.45f, 0.45f));
effect.Parameters["LightDistanceSquared"].SetValue(40.0f);
effect.Parameters["DiffuseColor"].SetValue(color);
effect.Parameters["AmbientLightColor"].SetValue(Color.Black.ToVector3());
effect.Parameters["EmissiveColor"].SetValue(Color.White.ToVector3());
effect.Parameters["SpecularColor"].SetValue(Color.White.ToVector3());
effect.Parameters["SpecularPower"].SetValue(10.0f);
if (texture != null)
{
effect.Parameters["DiffuseTexture"].SetValue(texture);
}
mesh.Draw();
}
}
pass.Apply();
}
}
It seems that the normals were the villain this time around. After correcting the normals in Blender, everything seems to work now.
I want to thank meds and Andrew Russell. Without your help I wouldn't have figured it out!
So now I know, when you have problems with your lighting, always check the normals first.