I'm programming in j2me.
How can I prevent screen rotation in j2me for all phones that support screen rotation?
thanks.
If you use Canvas to draw your screen (not LCDUI, not LWUIT, not any other framework) you may implement sizeChanged method to be notified when the rotation happens.
In such case you may draw your screen to an Image and use Sprite to rotate it. For example, to support only Landscape mode I used below code at constructor:
int width = Math.max(super.getWidth(), super.getHeight());
int height = Math.min(super.getWidth(), super.getHeight());
// screen and sprite are attributes
screen = Image.createImage(width, height);
sprite = new Sprite(screen);
if (super.getWidth() < super.getHeight()) { // portrait screen
sprite.setTransform(Sprite.TRANS_ROT90);
sprite.setPosition(0, 0);
}
And following methods:
public void sizeChanged (int w, int h) {
// lastWidth and lastHeight are attributes
lastWidth = w;
lastHeight = h;
if (sprite == null) return;
if (super.getWidth() < super.getHeight()) { // portrait screen
sprite.setTransform(Sprite.TRANS_ROT90);
} else {
sprite.setTransform(Sprite.TRANS_NONE);
}
sprite.setPosition(0, 0);
}
protected void paint(Graphics g1) {
if (super.getWidth() != lastWidth
|| super.getHeight() != lastHeight) {
sizeChanged(super.getWidth(), super.getHeight());
}
Graphics g = screen.getGraphics();
// ... do your drawing on g
this.sprite.setImage(screen, screen.getWidth(), screen.getHeight());
sprite.paint(g1);
}
As seen at http://smallandadaptive.blogspot.com.br/2009/08/fullscreen-landscape.html and http://smallandadaptive.blogspot.com.br/2010/03/adapting-to-sizechanged.html and http://smallandadaptive.blogspot.com.br/2011/04/sizechanged-not-called.html
Add to manifest
For Nokia devices:
Nokia-MIDlet-App-Orientation : Landscape
For Samsung devices:
MIDlet-ScreenMode : Landscape
Related
While using bitmap in Xamarin Forms Android I'm getting out of memory error while loading images which are of higher than the usual size.
void getImage() {
-------
imageView.setImageBitmap(Bitmap.createScaledBitmap(getBitmapFromViewUpdated(_view), (int) width, (int) height, true));
tempView = imageView;
--------
}
public static Bitmap getBitmapFromView(final View view) {
view.setLayoutParams(new LayoutParams(view.getWidth(),
view.getHeight()));
view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
final Bitmap bitmap_ = Bitmap
.createBitmap(view.getMeasuredWidth(),
view.getMeasuredHeight(),
Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bitmap_);
view.draw(c);
return bitmap_;
}
Bitmap getBitmapFromViewUpdated(final View view) {
if (view.getWidth() == 0 || view.getHeight() == 0)
view.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
else
view.setLayoutParams(new LayoutParams(view.getWidth(),
view.getHeight()));
view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
view.layout(0, 0, viewWidth, viewHeight);
final Bitmap bitmap_;
if(viewWidth>0 && viewHeight>0) {
bitmap_ = Bitmap
.createBitmap(viewWidth,
viewHeight, Bitmap.Config.ARGB_8888);
}
else
{
bitmap_= Bitmap
.createBitmap(view.getMeasuredWidth(),
view.getMeasuredHeight(),
Bitmap.Config.ARGB_8888);
}
Canvas c = new Canvas(bitmap_);
view.draw(c);
return bitmap_;
}
I have tried android:largeHeap=true, can achieve the result while using that but I need to know how to fix with bitmap resizing.
You can check these two links for efficient bitmap management in xamarin android
https://forums.xamarin.com/discussion/5716/disposing-of-bitmaps-properly
https://developer.xamarin.com/recipes/android/resources/general/load_large_bitmaps_efficiently/
GoodLuck!
I'm working with google cardboard in unity.
In my main scene I have a skybox with an image as texture.
How can I get the color of the pixel I'm looking?
The skybox is an element of mainCamera, that is child of "Head".
I put also GvrReticle as child of head; is it useful for my purpose?
Thanks
Basically you wait for the end of the frame so that the camera has rendered. Then you read the rendered data into a texture and get the center pixel.
edit Be aware that if you have a UI element rendered in the center it will show the UI element color not the color behind.
private Texture2D tex;
public Color center;
void Awake()
{
StartCoroutine(GetCenterPixel());
}
private void CreateTexture()
{
tex = new Texture2D(1, 1, TextureFormat.RGB24, false);
}
private IEnumerator GetCenterPixel()
{
CreateTexture();
while (true)
{
yield return new WaitForEndOfFrame();
tex.ReadPixels(new Rect(Screen.width / 2f, Screen.height / 2f, 1, 1), 0, 0);
tex.Apply();
center = tex.GetPixel(0,0);
}
}
Background information
I have just started learning HLSL and decided to test what I have learned from the Internet by writing a simple 2D XNA 4.0 bullet-hell game.
I have written a pixel shader in order to change the color of bullets.
Here is the idea: the original texture of the bullet is mainly black, white and red. With the help of my pixel shader, bullets can be much more colorful.
But, I'm not sure how and when the shader is applied on spriteBatch in XNA 4.0, and when it ends. This may be the cause of problem.
There were pass.begin() and pass.end() in XNA 3.x, but pass.apply() in XNA 4.0 confuses me.
In addition, it is the first time for me to use renderTarget. It may cause problems.
Symptom
It works, but only if there are bullets of the same color in the bullet list.
If bullets of different colors are rendered, it produces wrong colors.
It seems that the pixel shader is not applied on the bullet texture, but applied on the renderTarget, which contains all the rendered bullets.
For an example:
Here I have some red bullets and blue bullets. The last created bullet is a blue one. It seems that the pixel shader have added blue color on the red ones, making them to be blue-violet.
If I continuously create bullets, the red bullets will appear to be switching between red and blue-violet. (I believe that the blue ones are also switching, but not obvious.)
Code
Since I am new to HLSL, I don't really know what I have to provide.
Here are all the things that I believe or don't know if they are related to the problem.
C# - Enemy bullet (or just Bullet):
protected SpriteBatch spriteBatch;
protected Texture2D texture;
protected Effect colorEffect;
protected Color bulletColor;
... // And some unrelated variables
public EnemyBullet(SpriteBatch spriteBatch, Texture2D texture, Effect colorEffect, BulletType bulletType, (and other data, like velocity)
{
this.spriteBatch = spriteBatch;
this.texture = texture;
this.colorEffect = colorEffect;
if(bulletType == BulletType.ARROW_S)
{
bulletColor = Color.Red; // The bullet will be either red
}
else
{
bulletColor = Color.Blue; // or blue.
}
}
public void Update()
{
... // Update positions and other properties, but not the color.
}
public void Draw()
{
colorEffect.Parameters["DestColor"].SetValue(bulletColor.ToVector4());
int l = colorEffect.CurrentTechnique.Passes.Count();
for (int i = 0; i < l; i++)
{
colorEffect.CurrentTechnique.Passes[i].Apply();
spriteBatch.Draw(texture, Position, sourceRectangle, Color.White, (float)Math.PI - rotation_randian, origin, Scale, SpriteEffects.None, 0.0f);
}
}
C# - Bullet manager:
private Texture2D bulletTexture;
private List<EnemyBullet> enemyBullets;
private const int ENEMY_BULLET_CAPACITY = 10000;
private RenderTarget2D bulletsRenderTarget;
private Effect colorEffect;
...
public EnemyBulletManager()
{
enemyBullets = new List<EnemyBullet>(ENEMY_BULLET_CAPACITY);
}
public void LoadContent(ContentManager content, SpriteBatch spriteBatch)
{
bulletTexture = content.Load<Texture2D>(#"Textures\arrow_red2");
bulletsRenderTarget = new RenderTarget2D(spriteBatch.GraphicsDevice, spriteBatch.GraphicsDevice.PresentationParameters.BackBufferWidth, spriteBatch.GraphicsDevice.PresentationParameters.BackBufferHeight, false, SurfaceFormat.Color, DepthFormat.None);
colorEffect = content.Load<Effect>(#"Effects\ColorTransform");
colorEffect.Parameters["ColorMap"].SetValue(bulletTexture);
}
public void Update()
{
int l = enemyBullets.Count();
for (int i = 0; i < l; i++)
{
if (enemyBullets[i].IsAlive)
{
enemyBullets[i].Update();
}
else
{
enemyBullets.RemoveAt(i);
i--;
l--;
}
}
}
// This function is called before Draw()
public void PreDraw()
{
// spriteBatch.Begin() is called outside this class, for reference:
// spriteBatch.Begin(SpriteSortMode.Immediate, null);
spriteBatch.GraphicsDevice.SetRenderTarget(bulletsRenderTarget);
spriteBatch.GraphicsDevice.Clear(Color.Transparent);
int l = enemyBullets.Count();
for (int i = 0; i < l; i++)
{
if (enemyBullets[i].IsAlive)
{
enemyBullets[i].Draw();
}
}
spriteBatch.GraphicsDevice.SetRenderTarget(null);
}
public void Draw()
{
// Before this function is called,
// GraphicsDevice.Clear(Color.Black);
// is called outside.
spriteBatch.Draw(bulletsRenderTarget, Vector2.Zero, Color.White);
// spriteBatch.End();
}
// This function will be responsible for creating new bullets.
public EnemyBullet CreateBullet(EnemyBullet.BulletType bulletType, ...)
{
EnemyBullet eb = new EnemyBullet(spriteBatch, bulletTexture, colorEffect, bulletType, ...);
enemyBullets.Add(eb);
return eb;
}
HLSL - Effects\ColorTransform.fx
float4 DestColor;
texture2D ColorMap;
sampler2D ColorMapSampler = sampler_state
{
Texture = <ColorMap>;
};
struct PixelShaderInput
{
float2 TexCoord : TEXCOORD0;
};
float4 PixelShaderFunction(PixelShaderInput input) : COLOR0
{
float4 srcRGBA = tex2D(ColorMapSampler, input.TexCoord);
float fmax = max(srcRGBA.r, max(srcRGBA.g, srcRGBA.b));
float fmin = min(srcRGBA.r, min(srcRGBA.g, srcRGBA.b));
float delta = fmax - fmin;
float4 originalDestColor = float4(1, 0, 0, 1);
float4 deltaDestColor = originalDestColor - DestColor;
float4 finalRGBA = srcRGBA - (deltaDestColor * delta);
return finalRGBA;
}
technique Technique1
{
pass ColorTransform
{
PixelShader = compile ps_2_0 PixelShaderFunction();
}
}
I would be appreciate if anyone can help solving the problem. (Or optimizing my shader. I really know very little about HLSL.)
In XNA 4 you should pass the effect directly to the SpriteBatch, as explained on Shawn Hargreaves' Blog.
That said, it seems to me like the problem is, that after rendering your bullets to bulletsRenderTarget, you then draw that RenderTarget using the same spriteBatch with the last effect still in action. That would explain why the entire image is painted blue.
A solution would be to use two Begin()/End() passes of SpriteBatch, one with the effect and the other without. Or just don't use a separate RenderTarget to begin with, which seems pointless in this case.
I'm also very much a beginner with pixel shaders so, just my 2c.
how to develop a crop selection control like photoshop's in c# 4.0 in widows form application.
I have a windows form application in c# 4.0 that can crop images. At first you have to draw a rectangle using mouse to select the cropped region.
private Point _pt;
private Point _pt2;
private void picBoxImageProcessing_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
int ix = (int)(e.X / _zoom);
int iy = (int)(e.Y / _zoom);
//reset _pt2
_pt2 = new Point(0, 0);
_pt = new Point(ix, iy);
// pictureBox1.Invalidate();
picBoxImageProcessing.Invalidate();
}
}
private void picBoxImageProcessing_MouseUp(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left && _selecting)
{
_selecting = false;
}
}
private void picBoxImageProcessing_Paint(object sender, PaintEventArgs e)
{
if (_selecting &&_pt.X >= 0 && _pt.Y >= 0 && _pt2.X >= 0 && _pt2.Y >= 0)
{
e.Graphics.DrawRectangle(pen, _pt.X * _zoom, _pt.Y * _zoom,
(_pt2.X - _pt.X) * _zoom, (_pt2.Y - _pt.Y) * _zoom);
}
}
private void picBoxImageProcessing_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
_selecting = true;
int ix = (int)(e.X / _zoom);
int iy = (int)(e.Y / _zoom);
_pt2 = new Point(ix, iy);
// pictureBox1.Invalidate();
picBoxImageProcessing.Invalidate();
}
}
there is no problem to draw the rectangle by mouse dragging. But if i want to change the height or width of the rectangle then I have to draw a new rectangle, that i don't want. I want to change the height and width of the rectangle by modifying the drawn rectangle instead of drawing a new rectangle.
I don’t want to know how to crop. I need to draw a resizable rectangle on the image as we can do in photoshop.
So I need a crop selection control like photoshop's crop control.
Calling module:
private void Indicator_Move(object sender, EventArgs e)
{
Sizer size = new Sizer();
int x = this.Location.X;
int y = this.Location.Y;
int width = this.Width;
int height = this.Height;
var screenWidth = Screen.PrimaryScreen.WorkingArea.Width - 130;
if (x >= screenWidth)
{
size.checkmove(x, y, width, height, this);
}
else if (width == 158 )
{
width = 235;
height = 223;
this.Size = new System.Drawing.Size(width, height);
}
}
Module to Dock and reduce size from Sizer class:
public void checkmove(int movex, int movey,int width, int height, Form mover)
{
var moverheight = mover.Height;
var screenWidth = Screen.PrimaryScreen.WorkingArea.Width - 130;
var screenHeight = Screen.PrimaryScreen.WorkingArea.Height;
var finalx = screenWidth;
if (movex > screenWidth)
{
mover.Size = new System.Drawing.Size(154, 45);
mover.Location = new Point(finalx, screenHeight - 600);
}
}
I actually found a different way to accomplish what I wanted by the double_click event on the form and just moving it out on to the desktop it full size, but I am still curious why it resizes back and forth to full size and reduced size while moving and appearing to flicker and ending up reduced and only showing full size when the mouse button is clicked on form and held down. I'm thinking it has to do with the resizeend call anytime the form is moved. And thanks Joran for the edit.