I have got the code to repeat X- and Y- which is:
bg = [CCSprite spriteWithFile:#"ipadbgpattern.png" rect:CGRectMake(0, 0, 3000, 3000)];
bg.position = ccp(500,500);
ccTexParams params = {GL_LINEAR,GL_LINEAR,GL_REPEAT,GL_REPEAT};
[bg.texture setTexParameters:¶ms];
[self addChild:bg];
However, I do not know how to change the params in order for the background to repeat along the horizontal axis.
There's no parameter for that. Just make sure the CGRect spans the region where you want the texture to repeat, and the texture itself must be a power of two (ie 1024x1024).
I'm guessing that maybe you're using a 1024x768 texture and then you'll see a gap between texture repeats.
This cannot be achieved at the GL level, since GL_REPEAT expects textures with power-of-two dimensions.
Take a look at my TiledSprite class for a rather unoptimized, but functional means of arbitrarily repeating an arbitrarily-sized texture or subtexture:
https://gist.github.com/Nolithius/6694990
Here's a brief look at its results and usage:
http://www.nolithius.com/game-development/cocos2d-iphone-repeating-sprite
Related
I am adding the spritenode to the scene, the size is given.
But when I change the texture of the spritenode, the size automatically changes to the original size of the image(png) of the texture.
How can I avoid this?
My code:
var bomba = SKSpriteNode(imageNamed: "bomba2")
var actionbomba = SKAction()
bomba.size = CGSizeMake(frame2.size.width/18, frame2.size.width/18)
let bomba3 = SKTexture(imageNamed: "bomba3.png")
actionbomba.addObject(SKAction.moveBy(CGVectorMake(0, frame.size.height/2.65), duration: beweegsnelheid))
actionbomba.addObject(SKAction.setTexture(bomba3,resize: false))
addChild(bomba)
bomba.runAction(SKAction.repeatAction(SKAction.sequence(actionbomba), count: -1))
Do not set the size explicitly. From your information sprite kit will not automatically find the scale factor for each texture and scale it.
Instead, you set the scale factor of the node and each texture will have that scale applied to it.
[playernode setScale: x];
Something like this. You only have to set it when you create the node and each texture will be the size you would expect, given that your textures are the same size.
I use this method for all of my nodes that are animated with multiple textures and it works every time.
I want to draw UIimage with CGAffineTransform but It gives wrong output with CGContextConcatCTM
I have try with below code :
CGAffineTransform t = CGAffineTransformMake(1.67822, -1.38952, 1.38952, 1.67822, 278.684, 209.129); // transformation of uiimageview
UIGraphicsBeginImageContext(CGSizeMake(1024, 768));
CGContextRef imageContext = UIGraphicsGetCurrentContext();
CGContextDrawImage(imageContext, dragView.frame, dragView.image.CGImage);
CGContextConcatCTM(imageContext, t);
NSLog(#"\n%#\n%#", NSStringFromCGAffineTransform(t),NSStringFromCGAffineTransform(CGContextGetCTM(imageContext)));
Output :
[1.67822, -1.38952, 1.38952, 1.67822, 278.684, 209.129] // imageview transformation
[1.67822, 1.38952, 1.38952, -1.67822, 278.684, 558.871] // drawn image transformation
CGAffineTransform CGAffineTransformMake (
CGFloat a,
CGFloat b,
CGFloat c,
CGFloat d,
CGFloat tx,
CGFloat ty
);
Parameter b, d and ty changed, How to solve this?
There is no problem to solve. Your log output is correct.
Comparing the two matrixes, the difference between the two is this:
scale vertically by -1 (which affects two of the first four members)
translate vertically by 349.742 (which affects the last member)
I'm going to take a guess and say your view is about 350 points tall. Am I right? Actually, the 349.742 is weird, since you set the context's height to 768. It's almost half (perhaps because the anchor point is centered?), but well short, and cutting off the status bar wouldn't make sense here (and wouldn't account for a 68.516-point difference). So that is a puzzle. But, what follows is still true:
A vertical scale and translate is how you would flip a context. This context has gone from lower-left origin to upper-left origin, or vice versa.
That happened before you concatenated your (unexplained, hard-coded) matrix in. Assuming you didn't flip the context yourself, it probably came that way (I would guess as a UIKit implementation detail).
Concatenation (as in CGContextConcatCTM) does not replace the old transformation matrix with the new one; it is matrix multiplication. The matrix you have afterward is the product of both the matrix you started with and the one you concatenated onto it. The resulting matrix is both flipped and then… whatever your matrix does.
You can see this for yourself by simply getting the CTM before you concatenate your matrix onto it, and logging that. You should see this:
[0, -1, 0, -1, 0, 349.742]
See also “The Math Behind the Matrices” in the Quartz 2D Programming Guide.
I am trying to show bounding rectangles around my sprites to refine the collision detection and handling.
I have used following code to display circle or polygon
glColor4ub(255, 255, 0, 255);
glLineWidth(2);
CGPoint vertices2[] = { ccp(30,130), ccp(30,230), ccp(50,200) };
ccDrawPoly( vertices2, 3, YES);
ccDrawCircle(ccp(0,0), 50, 360, 5, NO);
as mentioned in drawPrimitivesTest.m file in cocos2d.
i removed all background sprites also. but it is not showing me any circle or polygon.
can anybody has faced same problem? how to solve this problem?
Thanks in advance.
You should not put that code outside of the draw method
TIP:
Every CocosNode has a "draw" method.
In the "draw" method you put all the code that actually draws your node.
And Test1 is a subclass of TestDemo, which is a subclass of Layer, which is a subclass of CocosNode.
As you can see the drawing primitives aren't CocosNode objects. They are just helper
functions that let's you draw basic things like: points, line, polygons and circles.
Answering
TIP:
Don't draw your stuff outide the "draw" method. Otherwise it wont get transformed.
TIP: If you want to rotate/translate/scale a circle or any other "primtive", you can do it by rotating
the node. eg:
self.rotation = 90;
I working on a spinning 3D cube (glFrustumf setup) and it multiplies the current matrix by the previous one so that the cube continues to spin. See below
/* save current rotation state */
GLfloat matrix[16];
glGetFloatv(GL_MODELVIEW_MATRIX, matrix);
/* re-center cube, apply new rotation */
glLoadIdentity();
glRotatef(self.angle, self.dy,self.dx,0);
glMultMatrixf(matrix);
The problem is I need to step back from this (as if I had a camera).
I tried to edit the matrix and that kind of works but picks up noise. The cube jumps around.
matrix[14] = -5.0;
matrix[13] = 0;
matrix[12] =0;
Is there a way to edit the current Modelview Matrix so that I can set the position of the cube with multiplying it by another matrix?
You should not mistreat OpenGL as a scene graph, nor a math library. That means: Don't read back the matrix, and multiply it arbitrarily back. Instead rebuild the whole matrix stack a new every time you do a render pass. I think I should point out, that in OpenGL-4 all the matrix functions have been removed. Instead you're expected to supply the matrices as uniforms.
EDIT due to comment by #Burf2000:
Your typical render handler will look something like this (pseudocode):
draw_object():
# bind VBO or plain VertexArrays (you might even use immediate mode, but that's deprecated)
# draw the stuff using glDrawArrays or better yet glDrawElements
render_subobject(object, parent_transform):
modelview = parent_tranform * object.transform
if OPENGL3_CORE:
glUniformMatrix4fv(object.shader.uniform_location[modelview], 1, 0, modelview)
else:
glLoadMatrixf(modelview)
draw_object(object)
for subobject in object.subobjects:
render_subobject(subobject, modelview)
render(deltaT, window, scene):
if use_physics:
PhysicsSimulateTimeStep(deltaT, scene.objects)
else:
for o in scene.objects:
o.animate(deltaT)
glClearColor(...)
glClearDepth(...)
glViewport(0, 0, window.width, window.height)
glDisable(GL_SCISSOR_TEST);
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT)
# ...
# now _some_ objects' render pass - others may precede or follow, like for creating reflection cubemaps or water refractions.
glViewport(0, 0, window.width, window.height)
glEnable(GL_DEPTH_TEST)
glDepthMask(1)
glColorMask(1,1,1,1)
if not OPENGL3_CORE:
glMatrixMode(GL_PROJECTION)
glLoadMatrixf(scene.projection.matrix)
for object in scene.objects:
bind_shader(object.shader)
if OPENGL3_CORE:
glUniformMatrix4fv(scene.projection_uniform, 1, 0, scene.projection.matrix)
# other render passes
glViewport(window.HUD.x, window.HUD.y, window.HUD.width, window.HUD.height)
glStencil(window.HUD.x, window.HUD.y, window.HUD.width, window.HUD.height)
glEnable(GL_STENCIL_TEST)
glDisable(GL_DEPTH_TEST)
if not OPENGL3_CORE:
glMatrixMode(GL_PROJECTION)
glLoadMatrixf(scene.HUD.projection.matrix)
render_HUD(...)
and so on. I hope you get the general idea. OpenGL is neither a scene graph, nor a matrix manipulation library.
I'm drawing some lines in cocos2d (using handy ccDrawLine), nothing fancy, but i want to check if my animated line hits something. I could do some math calculations for some objects, but for some dynamic parts in the scene it would be much easier if i could do:
if pixel not black at (x,y)
// line will hit something
do handleCollisionDetectedAt(x,y)
What would you suggest? At least what would you suggest if it would be simple OpenGL ES.
Found solution:
GLubyte pColor[4];
glReadPixels(x,y,1,1,GL_RGBA,GL_UNSIGNED_BYTE,&pColor[0]);
int red = pColor[0];
int green = pColor[1];
int blue = pColor[2];
NSLog(#"(R,G,B) = (%d,%d,%d)",red,green,blue);