I have a method that I use to render little map using tiles, but when I finish rendering and I want to make a translation changing "transY" variable using different method nothing happens, so I must call RenderTesture() again to make it. How can I do this withot unnecessary rendering because it can slow down application when I use larger number of tiles?
void RenderTexture ()
{
MakeCurrent ();
GL.Clear((int)All.ColorBufferBit | (int)All.DepthBufferBit);
GL.MatrixMode(All.Modelview);
GL.LoadIdentity();
GL.Translate(-transX, transY, -10);
for (int i = 0; i < tileRows; i++)
{
for (int j = 0; j < tileColumns; j++)
{
GL.BindTexture(All.Texture2D, textureIds [i*tileColumns + j]);
GL.EnableClientState(All.VertexArray);
GL.EnableClientState(All.TextureCoordArray);
GL.PushMatrix ();
GL.Translate(j*2, -i*2, 0);
GL.VertexPointer(3, All.Float, 0, frontV);
GL.TexCoordPointer(2, All.Float, 0, frontT);
GL.DrawArrays (All.TriangleFan, 0, 4);
GL.PopMatrix ();
}
}
GL.DisableClientState(All.VertexArray);
GL.DisableClientState(All.TextureCoordArray);
SwapBuffers ();
}
If anybody have advice for me, I'll be very grateful!
Thanks in advance!
The bottleneck lies, most likely, in the amount of state changes (GL.BindTexture) and the amount of draw calls you are making (GL.DrawArrays). In general, you should draw as much as possible in a single draw call.
The simplest approach wold be to use a "texture atlas":
combine all your tile textures into a single large texture (this is the "texture atlas")
combine all your tile vertices into a single vertex array
call GL.BindTexture once to bind the texture atlas
call GL.DrawArrays once to render all tiles
So how do you render different tile textures? Simple: you change the vertex texture coordinates to point to the correct tile inside the texture atlas.
A single 1024x1024 can hold 256 distinct 64x64 tiles. Depending on the amount of distinct tiles in your game, you might have to use multiple texture atlases. Moreover, depending on the size of your map, you might wish to split it into "regions" with separate vertex arrays for each (you don't want to render 1 million tiles every frame if your monitor can only display 1000 tiles.)
On its own, this will give a measurable performance boost. Once this is working, you can get a second large boost by storing your vertex arrays on the GPU via Vertex Buffer Objects (VBOs).
Thank you very much!
The "Texture atlas" strategy can be very good idea. I've implemented that last night and it looks like rendering is getting speed. I've reduce loading of NxM tiles using separate textures, by loading one big NxM tiles bitmap using single texture and I've implemented method to change vertex array (in regard to new bitmap dimensions - NxM)
public void UpdateFrontVertex(int rowNumber, int columnsNumber)
{
for (int i = 0; i < 12; i++) {
if (i % 3 == 0)
frontVertex [i] = defaultFrontVertex[i] * rowNumber; // x-axis
else if (i % 3 == 1)
frontVertex [i] = defaultFrontVertex[i] * columnsNumber; // y-axis
else if (i % 3 == 2)
frontVertex [i] = defaultFrontVertex[i]; // z-axis
}
}
After that, I've got my map!!!
I still cannot compare performances before that implementation and now because I have to make changes for panning and zooming functionalities to work with that new rendering strategy.
For example, I've used
//zoom in
transY = (transY * 2 + 1);
transX = (transX * 2 + 1);
//zoom out
transX = ((transX - 1) / 2);
transY = ((transY - 1) / 2);
for zooming calculations to figure out which tile is my central tile, and after that to load all rounding tiles.
Thank you again for great help, I'll proceed now with panning and zooming implementation.
Related
I am making a game based on the game AZ on the website Y8, and I am having problems with tile collisions.
the player moves basically by giving it speed when up is pressed, then rotating left or right.
direction = image_angle;
if(keyForward)
{
speed = 2;
}
else speed = 0;
// rotate
if(keyRotateLeft)
{
image_angle = image_angle + 5;
}
if(keyRotateRight)
{
image_angle = image_angle - 5;
}
then I said when the player collides with the tile speed = 0. But the player gets stuck and can't move anymore. is there a better way to do this.
A simple approach would be as following:
Attempt to rotate
Check if you are now stuck in a wall
If you are, undo the rotation.
A more advanced approach would be to attempt pushing the player out of solids while rotating.
Alternatively, you may be able to get away with giving the player a circular mask and not rotating the actual mask (using a user-defined variable instead of image_angle).
I am creating a small game in the Unity game engine, and the map for the game is generated from a 2d tilemap. The tilemap contains so many tiles, though, is is very hard for a device like a phone to render them all, so the frame rate drops. The map is completely static in that the only moving thing in the game is a main character sprite and the camera following it. The map itself has no moving objects, it is very simple, there must be a way to render only the needed sections of it or perhaps just render the map in once. All I have discovered from researching the topic is that perhaps a good way to do it is buy using the Unity mesh class to turn the tilemap into a mesh. I could not figure out how to do this with a 2d tilemap, and I could not see how it would benefit the render time anyways, but if anyone could point me in the right direction for rendering large 2d tilemaps that would be fantastic. Thanks.
Tile system:
To make the tile map work I put every individual tile as a prefab in my prefab folder, with the attributes changed for 2d box colliders and scaled size. I attribute each individual prefab of the tile to a certain color on the RGB scale, and then import a png file that has the corresponding colors of the prefabs where I want them like this:
I then wrote a script which will place each prefab where its associated color is. It would look like this for one tile:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Map : MonoBehaviour {
private int levelWidth;
private int levelHeight;
public Transform block13;
private Color[] tileColors;
public Color block13Color;
public Texture2D levelTexture;
public PlayerMobility playerMobility;
// Use this for initialization
void Start () {
levelWidth = levelTexture.width;
levelHeight = levelTexture.height;
loadLevel ();
}
// Update is called once per frame
void Update () {
}
void loadLevel(){
tileColors = new Color[levelWidth * levelHeight];
tileColors = levelTexture.GetPixels ();
for (int y = 0; y < levelHeight; y++) {
for (int x = 0; x < levelWidth; x++) {
// if (tileColors [x + y * levelWidth] == block13Color) {
// Instantiate(block13, new Vector3(x, y), Quaternion.identity);
// }
//
}
}
}
}
This results in a map that looks like this when used with all the code (I took out all the code for the other prefabs to save space)
You can instantiate tiles that are in range of the camera and destroy tiles that are not. There are several ways to do this. But first make sure that what's consuming your resources is in fact the large number of tiles, not something else.
One way is to create an empty parent gameObject to every tile (right click in "Hierarchy" > Create Empty"
then attach a script to this parent. This script has a reference to the camera (tell me if you need help with that) and calculates the distance between it and the camera and instantiates the tile if the distance is less than a value, otherwise destroys the instance (if it's there).
It has to do this in the Update function to check for the distances every frame, or you can use "Coroutines" to do less checks (more efficient).
Another way is to attach a script to the camera that has an array with instances of all tiles and checks on their distances from the camera the same way. You can do this if you only have exactly one large tilemap because it would be hard to re-use this script if you have more than a large tilemap.
Also you can calculate the distance between the tile and the character sprite instead of the camera. Pick whichever is more convenient.
After doing the above and you still get frame-drops you can zoom-in the camera to include less tiles in its range but you'd have to recalculate the distances then.
First time posting here. Tried to look for topics previously to help.
I'm using Visual Basic, but so far I've been able to follow C# and just translate into VB.
I would like collision without tiles. Smooth movement without any sort of snapping. I already have the movement down, and my sprites stop at the edges of the screen.
I've read I could use Bounds and Intersects, which I have tried. When I apply an IF statement to the arrow keys each time they are pressed, using Bounds and Intersects (I just prevent sprite movement if it is intersecting), it works for ONE key. I move left into an object, and I stop. If I apply the IF to all keys, it will work the first time. Say I move left into an object, the IF statement checks if the Intersects is true or not and acts accordingly.
Now I want to move right, away from the object. I can't since my sprite is ALREADY colliding with the object, since each arrow key is programmed to NOT move if there is Intersection. I see perfectly why this happens.
The code I currently have: (Each arrow key has the same code, altered to it)
If Keyboard.GetState(PlayerIndex.One).IsKeyDown(Keys.Right) And rBlockBounds.X <=
graphics.GraphicsDevice.Viewport.Width - rBlockBounds.Width = True Then
If rBlockBoundBoxBounds.Intersects(rObstructBounds) Then
rBlockBounds.X += 0
rBlockBoundBoxBounds.X = rBlockBounds.X - 1
Else
rBlockBounds.X += 1
rBlockBoundBoxBounds.X = rBlockBounds.X - 1
End If
End If
rBlockBounds is my sprite As Rectangle
rBlockBoundBoxBounds is another Rectangle (1 pixle bigger than rBlockBounds) used as a Hit Box more or less that moves with rBlockBounds, and is the thing doing the collision checking
rObstructBounds is the stationary object that I'm moving my Sprite into.
Anyone have suggestions on how I can make this work?
Since I myself program in C#, not VB I can not code your solution but instead I can explain a better way of approaching it.
What you want to do is prevent the two rectangles from ever intersecting. To do this you will need to implement a move method into your code which can check if the two tiles are colliding. Here is a C# example:
public bool MoveX(float distance) // Move Player Horizontally in this example
{
rBlockBounds.X += distance;
if(rBlockBoundBoxBounds.Intersects(rObstructBounds)
{
rBlockBounds.X -= distance;
return false;
}
return true;
}
Which essentially means that if you run into an object you will be pushed out of it. Since it occurs in one tick you won't get any jutty back-and-front animations.
And that should do what you want. You can test this out and then implement it for y-coordinates as well.
Also, you might notice I've made the function return a bool. This is optional but allows you to check if your player has moved or not.
Note if you teleport an object into another one it will cause problems so remember to implement this every time you move anything.
But that should do what you want.
Edit
Note since your objects are not in a tiled grid, you will need to move lots of time in very small steps.
Something like this:
public bool MoveX(float distance) // Move Player Horizontally in this example
{
rBlockBounds.X += distance;
if(rBlockBoundBoxBounds.Intersects(rObstructBounds)
{
rBlockBounds.X -= distance;
return false;
}
return true;
}
public bool MoveX(float distance, int repeat)
{
for(int i=0; i < repeat; i++)
{
rBlockBounds.X += distance;
if(rBlockBoundBoxBounds.Intersects(rObstructBounds)
{
rBlockBounds.X -= distance;
return false;
}
}
return true;
}
Where the second one will take multiple steps. Here is why you would use it:
MoveX(500); // Will move 500 right. Could easily skip over objects!
MoveX(5, 100); // Will move 5 right one hundred times
// ^ This will take more time but will not skip object
Similarly for yours you could do this:
MoveX(3); // If contact object will be max 3 pixels away
MoveX(1, 3); // If contact object will be max 1 pixels away
MoveX(0.5f, 6); // If contact object will be max 0.5 pixels away
Now I am guessing all your x, y positions are integers. If so you could get away doing the second call and come exactly next to each other. If not you would do the third call.
Hope this helped.
I'm searching for a program which detects the border of a image,
for example I have a square and the program detects the X/Y-Coords
Example:
alt text http://img709.imageshack.us/img709/1341/22444641.png
This is a very simple edge detector. It is suitable for binary images. It just calculates the differences between horizontal and vertical pixels like image.pos[1,1] = image.pos[1,1] - image.pos[1,2] and the same for vertical differences. Bear in mind that you also need to normalize it in the range of values 0..255.
But! if you just need a program, use Adobe Photoshop.
Code written in C#.
public void SimpleEdgeDetection()
{
BitmapData data = Util.SetImageToProcess(image);
if (image.PixelFormat != PixelFormat.Format8bppIndexed)
return;
unsafe
{
byte* ptr1 = (byte *)data.Scan0;
byte* ptr2;
int offset = data.Stride - data.Width;
int height = data.Height - 1;
int px;
for (int y = 0; y < height; y++)
{
ptr2 = (byte*)ptr1 + data.Stride;
for (int x = 0; x < data.Width; x++, ptr1++, ptr2++)
{
px = Math.Abs(ptr1[0] - ptr1[1]) + Math.Abs(ptr1[0] - ptr2[0]);
if (px > Util.MaxGrayLevel) px = Util.MaxGrayLevel;
ptr1[0] = (byte)px;
}
ptr1 += offset;
}
}
image.UnlockBits(data);
}
Method from Util Class
static public BitmapData SetImageToProcess(Bitmap image)
{
if (image != null)
return image.LockBits(
new Rectangle(0, 0, image.Width, image.Height),
ImageLockMode.ReadWrite,
image.PixelFormat);
return null;
}
If you need more explanation or algorithm just ask with more information without being so general.
It depends what you want to do with the border, if you are looking at getting just the values of the edges of the region, use an algorithm called the Connected Components Region. You must know the value of the region prior to using the algorithm. This will navigate around the border and collect the outside region. If you are trying to detect just the outside lines get the gradient of the image and it will reveal where the lines are. To do this convolve the image with an edge detection filter such as Prewitt, Sobel, etc.
You can use any image processing library such as Opencv. which is in c++ or python.
You should look for edge detection functions such as Canny edge detection.
Of course this would require some diving into image processing.
The example image you gave should be straight forward to detect, how noisy/varied are the images going to be?
A shape recognition algorithm might help you out, providing it has a solid border of some kind, and the background colour is a solid one.
From the sounds of it, you just want a blob extraction algorithm. After that, the lowest/highest values for x/y will give you the coordinates of the corners.
In my glut application I'm simulating a plane with the camera. When the planes speed is low I intend to have the nose start to point towards the ground as the camera falls. My first instinct was to just change the pitch until it was pointed downwards at -90degrees. However I can't just change the pitch because if the plane is tilted on its side or upside down then it would note be changing direction towards the ground.
Now i'm trying to do a rough simulation of this by shifting the 'lookAt.y' downwards. To do this I am trying to get all the current camera coordinates that I use to set the camera
(eye.x, eye.y, eye.z, look.x, look.y, look.z, up.x, up.y, up.z). Then recall the set with the new modified values.
I've been working with the Camera.cpp and Camera.h to control my camera functions. They can be found here
after adding methods to get all the values, only the eye values are actually updated when various camera motions are made. I guess my question is how do I retrieve these values.
The glLoadMaxtrix call is in this function
void Camera :: setModelViewMatrix(void)
{ // load model view matrix with existing camera values
float m[16];
Vector3 eVec(eye.x, eye.y, eye.z);
m[0] = u.x; m[4] = u.y; m[8] = u.z; m[12] = -eVec.dot(u);
m[1] = v.x; m[5] = v.y; m[9] = v.z; m[13] = -eVec.dot(v);
m[2] = n.x; m[6] = n.y; m[10] = n.z; m[14] = -eVec.dot(n);
m[3] = 0; m[7] = 0; m[11] = 0; m[15] = 1.0;
look.x = u.y; look.y = v.y; look.z = n.y;
glMatrixMode(GL_MODELVIEW);
glLoadMatrixf(m);
}
Is there a way to get 'eye', 'lookAt', and 'up' values from the matrix here? Or should I do something else to get these values?
-Thanks in advance for your help
The camera class you link to is not an actual OpenGL class, but it should be simple enough to work with.
The function quoted just takes the current values of the camera object and sends them to OpenGL. If you look at the camera's set function, you can see how the program calculates the values it actually stores.
The eye value is stored directly. The lookAt value is just the value of (eye - n), by vector math. The up value is the hardest, but if I remember my vector math correctly, I believe that up = (n cross u).