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• When to call glEnable(GL_FRAMEBUFFER_SRGB)?

  - by Steven Lu

  I have a rendering system where I draw to an FBO with a multisampled renderbuffer, then blit it to another FBO with a texture in order to resolve the samples in order to read off the texture to perform post-processing shading while drawing to the backbuffer (FBO index 0). Now I'd like to get some correct sRGB output... The problem is the behavior of the program is rather inconsistent between when I run it on OS X and Windows and this also changes depending on the machine: On Windows with the Intel HD 3000 it will not apply the sRGB nonlinearity but on my other machine with a Nvidia GTX 670 it does. On the Intel HD 3000 in OS X it will also apply it. So this probably means that I'm not setting my GL_FRAMEBUFFER_SRGB enable state at the right points in the program. However I can't seem to find any tutorials that actually tell me when I ought to enable it, they only ever mention that it's dead easy and comes at no performance cost. I am currently not loading in any textures so I haven't had a need to deal with linearizing their colors yet. To force the program to not simply spit back out the linear color values, what I have tried is simply comment out my glDisable(GL_FRAMEBUFFER_SRGB) line, which effectively means this setting is enabled for the entire pipeline, and I actually redundantly force it back on every frame. I don't know if this is correct or not. It certainly does apply a nonlinearization to the colors but I can't tell if this is getting applied twice (which would be bad). It could apply the gamma as I render to my first FBO. It could do it when I blit the first FBO to the second FBO. Why not? I've gone so far as to take screen shots of my final frame and compare raw pixel color values to the colors I set them to in the program: I set the input color to RGB(1,2,3) and the output is RGB(13,22,28). That seems like quite a lot of color compression at the low end and leads me to question if the gamma is getting applied multiple times. I have just now gone through the sRGB equation and I can verify that the conversion seems to be only applied once as linear 1/255, 2/255, and 3/255 do indeed map to sRGB 13/255, 22/255, and 28/255 using the equation 1.055*C^(1/2.4)+0.055. Given that the expansion is so large for these low color values it really should be obvious if the sRGB color transform is getting applied more than once. So, I still haven't determined what the right thing to do is. does glEnable(GL_FRAMEBUFFER_SRGB) only apply to the final framebuffer values, in which case I can just set this during my GL init routine and forget about it hereafter?

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• error in coding in pygame.

  - by mekasperasky

  import pygame from pygame.locals import * screen=pygame.display.set_mode() nin=pygame.image.load('/home/satyajit/Desktop/nincompoop0001.bmp') screen.blit(nin,(50,100)) according to the code i should get a screen with an image of nin on it . But I only get a black screen which doesnt go even though i press the exit button on it. how to get the image on the screen?

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• Can someone code review my small SDL app? Want to make sure I didn't make any beginner mistakes

  - by SDLFunTimes

  In an effort to teach myself the SDL library (hence my stack overflow handle :) ) I wanted to try my hand at a side-scroller. My code is complete but I want some feedback (mostly because I have an atrocious amount of if and else statements for what seems like some simple logic). My "program" is a c++ side-scroller where you move a single sprite across the screen. No jumping, bad guys, guns, scores, levels or anything. I wanted to use this as a base to build up upon. So I figured if my base is wrong I could end up with some pretty bad future apps. It's also multi-threaded. Next up on this I would like to make the person sprite animated (so it looks like he's walking rather than sliding) as well as make the person go faster when the arrow buttons are held down longer). The code is kind of long but here's my main method. There's a link at the bottom for the whole program: #include <iostream> #include "SDL.h" #include "game.hpp" using std::cout; using std::endl; const int SCREENW = 200; const int SCREENH = 200; const int BPP = 32; const int FPS = 24; int event_loop(void* stuff); int display_loop(void* stuff); int main(int argc, char** argv) { SDL_Init(SDL_INIT_EVERYTHING | SDL_INIT_EVENTTHREAD); SDL_Thread* events_thurd; SDL_Thread* display_thurd; SDL_Surface* screen = SDL_SetVideoMode(SCREENW, SCREENH, BPP, SDL_SWSURFACE); SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL); SDL_Event event; Game* thug_aim = new Game(&event, screen, SCREENW, SCREENH, BPP); events_thurd = SDL_CreateThread(event_loop, (void*)thug_aim); display_thurd = SDL_CreateThread(display_loop, (void*)thug_aim); SDL_WaitThread(events_thurd, NULL); SDL_KillThread(display_thurd); delete thug_aim; return 0; } int event_loop(void* stuff) { Game* gamez = (Game*)stuff; SDL_Event* event = gamez->get_event(); while(1) { while(SDL_PollEvent(event)) { if(event->type == SDL_QUIT) { return 0; } else if(event->type == SDL_KEYDOWN) { if(event->key.keysym.sym == SDLK_LEFT || event->key.keysym.sym == SDLK_RIGHT) { gamez->move(event->key.keysym.sym); } } else if(event->type == SDL_KEYUP) { if(event->key.keysym.sym == SDLK_LEFT || event->key.keysym.sym == SDLK_RIGHT) { gamez->stop_move(event->key.keysym.sym); } } else { //not an event that concerns this game } } } } int display_loop(void* stuff) { Game* gamez = (Game*)stuff; double period = 1 / FPS * 1000; Uint32 milli_period = (Uint32)period; //get some of the attributes from gamez SDL_Rect* background_rect = gamez->get_background_rect(); SDL_Rect* person_rect = gamez->get_person_rect(); SDL_Surface* screen = gamez->get_screen(); SDL_Surface* background = gamez->get_background(); SDL_Surface* person = gamez->get_person(); Uint32 start, end; int sleep; while(1) { start = SDL_GetTicks(); //blit background SDL_BlitSurface(background, background_rect, screen, NULL); //blit person SDL_BlitSurface(person, NULL, screen, person_rect); end = SDL_GetTicks(); sleep = milli_period - (end - start); if(sleep < 0) { sleep = 0; } SDL_Delay((Uint32)sleep); if(SDL_Flip(gamez->get_screen()) != 0) { cout << "error drawing to screen: " << SDL_GetError() << endl; } } } Here's the link to the .zip file of all my code (please ignore some of the variable names ;-) ): Anyway can you guys take a look and tell me what you think? url edit: holy crap I didn't know 2shared was such a shitty site. Looking for a better uploader than that or rapidshare / mediafire.

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• Scrolling a WriteableBitmap

  - by Skoder

  I need to simulate my background scrolling but I want to avoid moving my actual image control. Instead, I'd like to use a WriteableBitmap and use a blitting method. What would be the way to simulate an image scrolling upwards? I've tried various things buy I can't seem to get my head around the logic: //X pos, Y pos, width, height Rect src = new Rect(0, scrollSpeed , 480, height); Rect dest = new Rect(0, 700 - scrollSpeed , 480, height); //destination rect, source WriteableBitmap, source Rect, blend mode wb.Blit(destRect, wbSource, srcRect, BlendMode.None); scrollSpeed += 5; if (scrollSpeed > 700) scrollSpeed = 0; If height is 10, the image is quite fuzzy and moreso if the height is 1. If the height is a taller, the image is clearer, but it only seems to do a one to one copy. How can I 'scroll' the image so that it looks like it's moving up in a continuous loop? (The height of the screen is 700).

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• putpixel with pyglet

  - by pts

  I'm new to pyglet. I'd like to change a pixel from black to white at each on_draw iteration. So after 1000 iterations, there should be exactly 1000 white pixels in the window. However, I'd like to avoid calling 1000 draw operations in on_draw for that. So I'd like to create an image, do an RGB putpixel on the image, and blit the image to the screen. How can I do that? The pyglet documentation, the examples and the source code aren't too helpful on this.

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• C/C++ Allegro program causes Windows 7 to switch to Aero Basic

  - by Matt H

  Hi SO, I'm just trying out the allegro library, and here is the code which I've got so far: #include <allegro.h> int main(int argc, char *argv[]) { allegro_init(); // initialize the allegro libraries install_keyboard(); // initialize keyboard functions set_color_depth(16); // set the color depth set_gfx_mode(GFX_AUTODETECT_WINDOWED, 640, 480, 0, 0); // set up 640*480px window BITMAP *pic = NULL; pic = load_bitmap("C:/picture.bmp", NULL); // load the picture blit(pic, screen, 0, 0, 0, 0, 1000, 1000); readkey(); destroy_bitmap(pic); return 0; } END_OF_MAIN() It works fine, but when I run it, while the program's window is open, Windows 7 changes the theme from Aero to Aero basic. If you aren't sure what I mean, this pops up (I got this from Google, which is why it says Vista rather than Windows 7): 1) Why? 2) How can I ensure that this doesn't happen?

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• Why does my buffered GraphicsContext application have a flickering problem?

  - by Bibendum

  import wx class MainFrame(wx.Frame): def __init__(self,parent,title): wx.Frame.__init__(self, parent, title=title, size=(640,480)) self.mainPanel=DoubleBufferTest(self,-1) self.Show(True) class DoubleBufferTest(wx.Panel): def __init__(self,parent=None,id=-1): wx.Panel.__init__(self,parent,id,style=wx.FULL_REPAINT_ON_RESIZE) self.SetBackgroundColour("#FFFFFF") self.timer = wx.Timer(self) self.timer.Start(100) self.Bind(wx.EVT_TIMER, self.update, self.timer) self.Bind(wx.EVT_PAINT,self.onPaint) def onPaint(self,event): event.Skip() dc = wx.MemoryDC() dc.SelectObject(wx.EmptyBitmap(640, 480)) gc = wx.GraphicsContext.Create(dc) gc.PushState() gc.SetBrush(wx.Brush("#CFCFCF")) bgRect=gc.CreatePath() bgRect.AddRectangle(0,0,640,480) gc.FillPath(bgRect) gc.PopState() dc2=wx.PaintDC(self) dc2.Blit(0,0,640,480,dc,0,0) def update(self,event): self.Refresh() app = wx.App(False) f=MainFrame(None,"Test") app.MainLoop() I've come up with this code to draw double buffered GraphicsContext content onto a panel, but there's a constant flickering across the window. I've tried different kinds of paths, like lines and curves but it's still there and I don't know what's causing it.

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• How to make multiple windows using Win32 API

  - by Steven Lu

  I see plenty of tutorials and articles showing me how to make a simple windows program, which is great but none of them show me how to make multiple windows. Right now I have working code that creates and draws a layered window and I can blit stuff using GDI to draw anything I want on it, drag it around, even make it transparent, etc. But I wanted a second rectangular area that I can draw to, drag around, etc. In other words, a second window. Probably want it to be a child window. Question is, how do I make it? Also, if anybody knows any good resources (online preferably) like articles or tutorials for window management in the Windows API, please share.

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• 2D Engine scrolling on OpenGL via hardware?

  - by drudru

  hi, I'm using OpenGL as the bottom end for a 2D tiling engine. When everything is 2D, it is simple to optimize certain issues. For example, scrolling. If I know a certain section of the screen needs to scroll off the bottom, then I can just blit over that portion. I'm evening moving more than 1 pixel at a time. Without explicit hardware support (think old nintendo hw), this requires a lot of pixel writes. An on chip bitblt would be the next best thing. Essentially, I'm looking at how I can optimize my GL calls to use VRAM texture renders as efficient hardware blits. Is it possible to have GL scroll the framebuffer, or should I just resign myself to double-buffering and re-rendering an entire scene for each frame? Thx

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• Is Android (read typical devices) fast enough for a game that requires plotting pixel by pixel rather than blitting

  - by mP

  i have an idea for an Android game which is a little different from the typical game that usually moves sprites(bitmaps) around the screen. Id want to plot lots of little pixels to create my visuals. PROS no bitmaps required pixel plotting of stuff like "fire" can react to wind. no need to scale bitmaps, works w/ any screen res (lets pretend device can handle more drawing because its got a bigger screen). CONS slower to plot pixels than blit bitmaps need lot of animation frames. WISHES id like to update my game in real time, more is better 30fps is good but not essential, 15fps is enough. PERFORMANCE Q... Is the typical Android device fast enough to plot say half a screenful of pixels w/ a default background ? if full screen is not practical what window size should be able to handle such refreshes

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• Skewed: a rotating camera in a simple CPU-based voxel raycaster/raytracer

  - by voxelizr

  TL;DR -- in my first simple software voxel raycaster, I cannot get camera rotations to work, seemingly correct matrices notwithstanding. The result is skewed: like a flat rendering, correctly rotated, however distorted and without depth. (While axis-aligned ie. unrotated, depth and parallax are as expected.) I'm trying to write a simple voxel raycaster as a learning exercise. This is purely CPU based for now until I figure out how things work exactly -- fow now, OpenGL is just (ab)used to blit the generated bitmap to the screen as often as possible. Now I have gotten to the point where a perspective-projection camera can move through the world and I can render (mostly, minus some artifacts that need investigation) perspective-correct 3-dimensional views of the "world", which is basically empty but contains a voxel cube of the Stanford Bunny. So I have a camera that I can move up and down, strafe left and right and "walk forward/backward" -- all axis-aligned so far, no camera rotations. Herein lies my problem. Screenshot #1: correct depth when the camera is still strictly axis-aligned, ie. un-rotated. Now I have for a few days been trying to get rotation to work. The basic logic and theory behind matrices and 3D rotations, in theory, is very clear to me. Yet I have only ever achieved a "2.5 rendering" when the camera rotates... fish-eyey, bit like in Google Streetview: even though I have a volumetric world representation, it seems --no matter what I try-- like I would first create a rendering from the "front view", then rotate that flat rendering according to camera rotation. Needless to say, I'm by now aware that rotating rays is not particularly necessary and error-prone. Still, in my most recent setup, with the most simplified raycast ray-position-and-direction algorithm possible, my rotation still produces the same fish-eyey flat-render-rotated style looks: Screenshot #2: camera "rotated to the right by 39 degrees" -- note how the blue-shaded left-hand side of the cube from screen #2 is not visible in this rotation, yet by now "it really should"! Now of course I'm aware of this: in a simple axis-aligned-no-rotation-setup like I had in the beginning, the ray simply traverses in small steps the positive z-direction, diverging to the left or right and top or bottom only depending on pixel position and projection matrix. As I "rotate the camera to the right or left" -- ie I rotate it around the Y-axis -- those very steps should be simply transformed by the proper rotation matrix, right? So for forward-traversal the Z-step gets a bit smaller the more the cam rotates, offset by an "increase" in the X-step. Yet for the pixel-position-based horizontal+vertical-divergence, increasing fractions of the x-step need to be "added" to the z-step. Somehow, none of my many matrices that I experimented with, nor my experiments with matrix-less hardcoded verbose sin/cos calculations really get this part right. Here's my basic per-ray pre-traversal algorithm -- syntax in Go, but take it as pseudocode: fx and fy: pixel positions x and y rayPos: vec3 for the ray starting position in world-space (calculated as below) rayDir: vec3 for the xyz-steps to be added to rayPos in each step during ray traversal rayStep: a temporary vec3 camPos: vec3 for the camera position in world space camRad: vec3 for camera rotation in radians pmat: typical perspective projection matrix The algorithm / pseudocode: // 1: rayPos is for now "this pixel, as a vector on the view plane in 3d, at The Origin" rayPos.X, rayPos.Y, rayPos.Z = ((fx / width) - 0.5), ((fy / height) - 0.5), 0 // 2: rotate around Y axis depending on cam rotation. No prob since view plane still at Origin 0,0,0 rayPos.MultMat(num.NewDmat4RotationY(camRad.Y)) // 3: a temp vec3. planeDist is -0.15 or some such -- fov-based dist of view plane from eye and also the non-normalized, "in axis-aligned world" traversal step size "forward into the screen" rayStep.X, rayStep.Y, rayStep.Z = 0, 0, planeDist // 4: rotate this too -- 0,zstep should become some meaningful xzstep,xzstep rayStep.MultMat(num.NewDmat4RotationY(CamRad.Y)) // set up direction vector from still-origin-based-ray-position-off-rotated-view-plane plus rotated-zstep-vector rayDir.X, rayDir.Y, rayDir.Z = -rayPos.X - me.rayStep.X, -rayPos.Y, rayPos.Z + rayStep.Z // perspective projection rayDir.Normalize() rayDir.MultMat(pmat) // before traversal, the ray starting position has to be transformed from origin-relative to campos-relative rayPos.Add(camPos) I'm skipping the traversal and sampling parts -- as per screens #1 through #3, those are "basically mostly correct" (though not pretty) -- when axis-aligned / unrotated.

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• [Silverlight] How to watermark a WriteableBitmap with a text

  - by Benjamin Roux

  Hello, In my current project, I needed to watermark a WriteableBitmap with a text. As I couldn’t find anything I decided to create a small extension method to do so. public static class WriteableBitmapEx { /// <summary> /// Creates a watermark on the specified image /// </summary> /// <param name="input">The image to create the watermark from</param> /// <param name="watermark">The text to watermark</param> /// <param name="color">The color - default is White</param> /// <param name="fontSize">The font size - default is 50</param> /// <param name="opacity">The opacity - default is 0.25</param> /// <param name="hasDropShadow">Specifies if a drop shadow effect must be added - default is true</param> /// <returns>The watermarked image</returns> public static WriteableBitmap Watermark(this WriteableBitmap input, string watermark, Color color = default(Color), double fontSize = 50, double opacity = 0.25, bool hasDropShadow = true) { var watermarked = GetTextBitmap(watermark, fontSize, color == default(Color) ? Colors.White : color, opacity, hasDropShadow); var width = watermarked.PixelWidth; var height = watermarked.PixelHeight; var result = input.Clone(); var position = new Rect(input.PixelWidth - width - 20 /* right margin */, input.PixelHeight - height, width, height); result.Blit(position, watermarked, new Rect(0, 0, width, height)); return result; } /// <summary> /// Creates a WriteableBitmap from a text /// </summary> /// <param name="text"></param> /// <param name="fontSize"></param> /// <param name="color"></param> /// <param name="opacity"></param> /// <param name="hasDropShadow"></param> /// <returns></returns> private static WriteableBitmap GetTextBitmap(string text, double fontSize, Color color, double opacity, bool hasDropShadow) { TextBlock txt = new TextBlock(); txt.Text = text; txt.FontSize = fontSize; txt.Foreground = new SolidColorBrush(color); txt.Opacity = opacity; if (hasDropShadow) txt.Effect = new DropShadowEffect(); WriteableBitmap bitmap = new WriteableBitmap((int)txt.ActualWidth, (int)txt.ActualHeight); bitmap.Render(txt, null); bitmap.Invalidate(); return bitmap; } } For this code to run, you need the WritableBitmapEx library. As you can see, it’s quite simple. You just need to call the Watermark method and pass it the text you want to add in your image. You can also pass optional parameters like the color, the opacity, the fontsize or if you want a drop shadow effect. I could have specify other parameters like the position or the the font family but you can change the code if you need to. Here’s what it can give Hope this helps.

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• Bounding Box Collision Glitching Problem (Pygame)

  - by Ericson Willians

  So far the "Bounding Box" method is the only one that I know. It's efficient enough to deal with simple games. Nevertheless, the game I'm developing is not that simple anymore and for that reason, I've made a simplified example of the problem. (It's worth noticing that I don't have rotating sprites on my game or anything like that. After showing the code, I'll explain better). Here's the whole code: from pygame import * DONE = False screen = display.set_mode((1024,768)) class Thing(): def __init__(self,x,y,w,h,s,c): self.x = x self.y = y self.w = w self.h = h self.s = s self.sur = Surface((64,48)) draw.rect(self.sur,c,(self.x,self.y,w,h),1) self.sur.fill(c) def draw(self): screen.blit(self.sur,(self.x,self.y)) def move(self,x): if key.get_pressed()[K_w] or key.get_pressed()[K_UP]: if x == 1: self.y -= self.s else: self.y += self.s if key.get_pressed()[K_s] or key.get_pressed()[K_DOWN]: if x == 1: self.y += self.s else: self.y -= self.s if key.get_pressed()[K_a] or key.get_pressed()[K_LEFT]: if x == 1: self.x -= self.s else: self.x += self.s if key.get_pressed()[K_d] or key.get_pressed()[K_RIGHT]: if x == 1: self.x += self.s else: self.x -= self.s def warp(self): if self.y < -48: self.y = 768 if self.y > 768 + 48: self.y = 0 if self.x < -64: self.x = 1024 + 64 if self.x > 1024 + 64: self.x = -64 r1 = Thing(0,0,64,48,1,(0,255,0)) r2 = Thing(6*64,6*48,64,48,1,(255,0,0)) while not DONE: screen.fill((0,0,0)) r2.draw() r1.draw() # If not intersecting, then moves, else, it moves in the opposite direction. if not ((((r1.x + r1.w) > (r2.x - r1.s)) and (r1.x < ((r2.x + r2.w) + r1.s))) and (((r1.y + r1.h) > (r2.y - r1.s)) and (r1.y < ((r2.y + r2.h) + r1.s)))): r1.move(1) else: r1.move(0) r1.warp() if key.get_pressed()[K_ESCAPE]: DONE = True for ev in event.get(): if ev.type == QUIT: DONE = True display.update() quit() The problem: In my actual game, the grid is fixed and each tile has 64 by 48 pixels. I know how to deal with collision perfectly if I moved by that size. Nevertheless, obviously, the player moves really fast. In the example, the collision is detected pretty well (Just as I see in many examples throughout the internet). The problem is that if I put the player to move WHEN IS NOT intersecting, then, when it touches the obstacle, it does not move anymore. Giving that problem, I began switching the directions, but then, when it touches and I press the opposite key, it "glitches through". My actual game has many walls, and the player will touch them many times, and I can't afford letting the player go through them. The code-problem illustrated: When the player goes towards the wall (Fine). When the player goes towards the wall and press the opposite direction. (It glitches through). Here is the logic I've designed before implementing it: I don't know any other method, and I really just want to have walls fixed in a grid, but move by 1 or 2 or 3 pixels (Slowly) and have perfect collision without glitching-possibilities. What do you suggest?

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• motion computation from video using pyglet in python

  - by kuaywai

  Hi, I am writing a simple motion detection program but i want it to be cross platform so im using python and the pyglet library since it provides a simple way to load videos in different formats (specially wmv and mpeg). So far i have the code given below which loads the movie and plays it in a window. Now i need to: 1) grab frame at time t and t-1 2) do a subtraction to see which pixels are active for motion detection. any ideas on how to grab frames and to skip over frames and is it possible to put the pixel values into a matrix in numpy or something directly from pyglet? or should look into using something other than pyglet? thanks kuaywai import pyglet import sys window = pyglet.window.Window(resizable=True) window.set_minimum_size(320,200) window.set_caption('Motion detect 1.0') video_intro = pyglet.resource.media('movie1.wmv') player = pyglet.media.Player() player.queue(video_intro) print 'calculating movie size...' if not player.source or not player.source.video_format: sys.exit myWidth = player.source.video_format.width myHeight = player.source.video_format.height if player.source.video_format.sample_aspect 1: myWidth *= player.source.video_format.sample_aspect elif player.source.video_format.sample_aspect < 1: myHeight /= player.source.video_format.sample_aspect print 'its size is %d,%d' % (myWidth,myHeight) player.play() @window.event def on_draw(): window.clear() (w,h) = window.get_size() player.get_texture().blit(0, h-myHeight, width=myWidth, height=myHeight) pyglet.app.run()

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• Scrolling a Canvas smoothly in Android

  - by prepbgg

  I'm new to Android. I am drawing bitmaps, lines and shapes onto a Canvas inside the OnDraw(Canvas canvas) method of my view. I am looking for help on how to implement smooth scrolling in response to a drag by the user. I have searched but not found any tutorials to help me with this. The reference for Canvas seems to say that if a Canvas is constructed from a Bitmap (called bmpBuffer, say) then anything drawn on the Canvas is also drawn on bmpBuffer. Would it be possible to use bmpBuffer to implement a scroll ... perhaps copy it back to the Canvas shifted by a few pixels at a time? But if I use Canvas.drawBitmap to draw bmpBuffer back to Canvas shifted by a few pixels, won't bmpBuffer be corrupted? Perhaps, therefore, I should copy bmpBuffer to bmpBuffer2 then draw bmpBuffer2 back to the Canvas. A more straightforward approach would be to draw the lines, shapes, etc. straight into a buffer Bitmap then draw that buffer (with a shift) onto the Canvas but so far as I can see the various methods: drawLine(), drawShape() and so on are not available for drawing to a Bitmap ... only to a Canvas. Could I have 2 Canvases? One of which would be constructed from the buffer bitmap and used simply for plotting the lines, shapes, etc. and then the buffer bitmap would be drawn onto the other Canvas for display in the View? I should welcome any advice! Answers to similar questions here (and on other websites) refer to "blitting". I understand the concept but can't find anything about "blit" or "bitblt" in the Android documentation. Are Canvas.drawBitmap and Bitmap.Copy Android's equivalents?

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• How to implement escape Sequence in SDL

  - by Sa'me Smd

  Im trying to use the STL library inside the SDL. but it gives me the error "undeclared identifier" Is there any way i can use "\n"or even cout<<endl; Can the function SDL_WarpMousewhich places the mouse cursor on a desired location on screen help me with this. Because i want to put a tile on the next line sequence. I hope you get the Question. Its very vague and messed up question though (sorry for that). EDIT: void putMap(SDL_Surface* tile, SDL_Surface* screen) { for(int y = 0; y < 21; y++) { for(int x = 0; x < 60; x++) { if(maze[x][y] != '#') { apply_surface( x*10 , y*10 , tile, screen); } } cout<<endl; } } c:\documents and settings\administrator\my documents\visual studio 2008\projects\craptest\craptest\main.cpp(605) : error C2065: 'cout' : undeclared identifier c:\documents and settings\administrator\my documents\visual studio 2008\projects\craptest\craptest\main.cpp(605) : error C2065: 'endl' : undeclared identifier This is my apply_surface funtion. void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination ) { //Make a temporary rectangle to hold the offsets SDL_Rect offset; //Give the offsets to the rectangle offset.x = x; offset.y = y; //Blit the surface SDL_BlitSurface( source, NULL, destination, &offset ); }

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• Sparse (Pseudo) Infinite Grid Data Structure for Web Game

  - by Ming

  I'm considering trying to make a game that takes place on an essentially infinite grid. The grid is very sparse. Certain small regions of relatively high density. Relatively few isolated nonempty cells. The amount of the grid in use is too large to implement naively but probably smallish by "big data" standards (I'm not trying to map the Internet or anything like that) This needs to be easy to persist. Here are the operations I may want to perform (reasonably efficiently) on this grid: Ask for some small rectangular region of cells and all their contents (a player's current neighborhood) Set individual cells or blit small regions (the player is making a move) Ask for the rough shape or outline/silhouette of some larger rectangular regions (a world map or region preview) Find some regions with approximately a given density (player spawning location) Approximate shortest path through gaps of at most some small constant empty spaces per hop (it's OK to be a bad approximation often, but not OK to keep heading the wrong direction searching) Approximate convex hull for a region Here's the catch: I want to do this in a web app. That is, I would prefer to use existing data storage (perhaps in the form of a relational database) and relatively little external dependency (preferably avoiding the need for a persistent process). Guys, what advice can you give me on actually implementing this? How would you do this if the web-app restrictions weren't in place? How would you modify that if they were? Thanks a lot, everyone!

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• Using the contents of an array to set individual pixels in a Quartz bitmap context

  - by Magic Bullet Dave

  I have an array that contains the RGB colour values for each pixel in a 320 x 180 display. I would like to be able to set individual pixel values in the a bitmap context of the same size offscreen then display the bitmap context in a view. It appears that I have to create 1x1 rects and either put a stroke on them or a line of length 1 at the point in question. Is that correct? I'm looking for a very efficient way of getting the array data onto the graphics context as you can imagine this is going to be an image buffer that cycles at 25 frames per second and drawing in this way seems inefficient. I guess the other question is should I use OPENGL ES instead? Thoughts/best practice would be much appreciated. Regards Dave OK, have come a short way, but can't make the final hurdle and I am not sure why this isn't working: - (void) displayContentsOfArray1UsingBitmap: (CGContextRef)context { long bitmapData[WIDTH * HEIGHT]; // Build bitmap int i, j, h; for (i = 0; i < WIDTH; i++) { for (j = 0; j < HEIGHT; j++) { h = frameBuffer01[i][j]; bitmapData[i * j] = h; } } // Blit the bitmap to the context CGDataProviderRef providerRef = CGDataProviderCreateWithData(NULL, bitmapData,4 * WIDTH * HEIGHT, NULL); CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB(); CGImageRef imageRef = CGImageCreate(WIDTH, HEIGHT, 8, 32, WIDTH * 4, colorSpaceRef, kCGImageAlphaFirst, providerRef, NULL, YES, kCGRenderingIntentDefault); CGContextDrawImage(context, CGRectMake(0.0, HEIGHT, WIDTH, HEIGHT), imageRef); CGImageRelease(imageRef); CGColorSpaceRelease(colorSpaceRef); CGDataProviderRelease(providerRef); }

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• error in a pygame code

  - by mekasperasky

  # INTIALISATION import pygame, math, sys from pygame.locals import * screen = pygame.display.set_mode((1024, 768)) car = pygame.image.load('car.png') clock = pygame.time.Clock() k_up = k_down = k_left = k_right = 0 speed = direction = 0 position = (100, 100) TURN_SPEED = 5 ACCELERATION = 2 MAX_FORWARD_SPEED = 10 MAX_REVERSE_SPEED = ­5 BLACK = (0,0,0) while 1: # USER INPUT clock.tick(30) for event in pygame.event.get(): if not hasattr(event, 'key'): continue down = event.type == KEYDOWN # key down or up? if event.key == K_RIGHT: k_right = down * ­5 elif event.key == K_LEFT: k_left = down * 5 elif event.key == K_UP: k_up = down * 2 elif event.key == K_DOWN: k_down = down * ­2 elif event.key == K_ESCAPE: sys.exit(0) # quit the game screen.fill(BLACK) # SIMULATION # .. new speed and direction based on acceleration and turn speed += (k_up + k_down) if speed > MAX_FORWARD_SPEED: speed = MAX_FORWARD_SPEED if speed < MAX_REVERSE_SPEED: speed = MAX_REVERSE_SPEED direction += (k_right + k_left) # .. new position based on current position, speed and direction x, y = position rad = direction * math.pi / 180 x += ­speed*math.sin(rad) y += ­speed*math.cos(rad) position = (x, y) # RENDERING # .. rotate the car image for direction rotated = pygame.transform.rotate(car, direction) # .. position the car on screen rect = rotated.get_rect() rect.center = position # .. render the car to screen screen.blit(rotated, rect) pygame.display.flip() enter code here the error i get is this Non-ASCII character '\xc2' in file race1.py on line 13, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details Not able to understand what the error is and how to get rid of it?

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• Pygame Sprite/Font rendering issues

  - by Grimless

  Hey guys. Here's my problem: I have a game class that maintains a HUD overlay that has a bunch of elements, including header and footer background sprites. Everything was working fine until I added a 1024x128 footer sprite. Now two of my text labels will not render, despite the fact that they DO exist in my Group and self.elements array. Is there something I'm missing? When I take out the footerHUDImage line, all of the labels render correctly and everything works fine. When I add the footerHUDImage, two of the labels (the first two) no longer render and the third only sometimes renders. HELP PLEASE! Here is the code: class AoWHUD (object): def __init__(self, screen, delegate, dataSource): self.delegate = delegate self.dataSource = dataSource self.elements = [] headerHudImage = KJRImage("HUDBackground.png") self.elements.append(headerHudImage) headerHudImage.userInteractionEnabled = True footerHUDImage = KJRImage("ControlsBackground.png") self.elements.append(footerHUDImage) footerHUDImage.rect.bottom = screen.get_rect().height footerHUDImage.userInteractionEnabled = True lumberMessage = "Lumber: " + str(self.dataSource.lumber) lumberLabel = KJRLabel(lumberMessage, size = 48, color = (240, 200, 10)) lumberLabel.rect.topleft = (_kSpacingMultiple * 0, 0) self.elements.append(lumberLabel) stoneMessage = "Stone: " + str(self.dataSource.stone) stoneLabel = KJRLabel(stoneMessage, size = 48, color = (240, 200, 10)) stoneLabel.rect.topleft = (_kSpacingMultiple * 1, 0) self.elements.append(stoneLabel) metalMessage = "Metal: " + str(self.dataSource.metal) metalLabel = KJRLabel(metalMessage, size = 48, color = (240, 200, 10)) metalLabel.rect.topleft = (_kSpacingMultiple * 2, 0) self.elements.append(metalLabel) foodMessage = "Food: " + str(len(self.dataSource.units)) + "/" + str(self.dataSource.food) foodLabel = KJRLabel(foodMessage, size = 48, color = (240, 200, 10)) foodLabel.rect.topleft = (_kSpacingMultiple * 3, 0) self.elements.append(foodLabel) self.selectionSprites = {32 : pygame.image.load("Selected32.png").convert_alpha(), 64 : pygame.image.load("Selected64.png")} self._sprites_ = pygame.sprite.Group() for e in self.elements: self._sprites_.add(e) print self.elements def draw(self, screen): if self.dataSource.resourcesChanged: lumberMessage = "Lumber: " + str(self.dataSource.lumber) stoneMessage = "Stone: " + str(self.dataSource.stone) metalMessage = "Metal: " + str(self.dataSource.metal) foodMessage = "Food: " + str(len(self.dataSource.units)) + "/" + str(self.dataSource.food) self.elements[2].setText(lumberMessage) self.elements[2].rect.topleft = (_kSpacingMultiple * 0, 0) self.elements[3].setText(stoneMessage) self.elements[3].rect.topleft = (_kSpacingMultiple * 1, 0) self.elements[4].setText(metalMessage) self.elements[4].rect.topleft = (_kSpacingMultiple * 2, 0) self.elements[5].setText(foodMessage) self.elements[5].rect.topleft = (_kSpacingMultiple * 3, 0) self.dataSource.resourcesChanged = False self._sprites_.draw(screen) if self.delegate.selectedUnit: theSelectionSprite = self.selectionSprites[self.delegate.selectedUnit.rect.width] screen.blit(theSelectionSprite, self.delegate.selectedUnit.rect)

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• How to draw a part of a window into a memory device context?

  - by Nell

  I'm using simple statements to keep it, er, simple: The screen goes from 0, 0 to 1000, 1000 (screen coordinates). A window goes from 100, 100 to 900, 900 (screen coordinates). I have a memory device context that goes from 0, 0 to 200, 200 (logical coordinates). I need to send a WM_PRINT message to the window. I can pass the device context to the window via WM_PRINT, but I cannot pass which part of its window it should draw into the device context. Is there some way to alter the device context that will result in the window drawing a specific part of itself into the device context (say, its bottom right portion from 700, 700 to 900, 900)? (This is all under plain old GDI and in C or C++. Any solution must be too.) Please note: This problem is part of a larger solution in which the device context size is fixed and speed is crucial, so I cannot draw the window in full into a separate device context and blit the part I want from the resultant full bitmap into my device context.

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• Changing direction of rotation Pygame

  - by czl

  How would you change the direction of a rotating image/rect in Pygame? Applying positive and negative degree values works but it seems to only be able to rotate one direction throughout my window. Is there a way to ensure a change in direction of rotation? Perhaps change up rotation of a spinning image every 5 seconds, or if able to change the direction of the spin when hitting a X or Y axis. I've added some code below. It seems like switching movement directions is easy with rect.move_ip as long as I specify a speed and have location clause, it does what I want. Unfortunately rotation is't like that. Here I'l adding angles to make sure it spins, but no matter what I try, I'm unable to negate the rotation. def rotate_image(self): #rotate image orig_rect = self.image.get_rect() rot_image = pygame.transform.rotate(self.image, self.angle) rot_rect = orig_rect.copy() rot_rect.center = rot_image.get_rect().center rot_image = rot_image.subsurface(rot_rect).copy() return rot_image def render(self): self.screen.fill(self.bg_color) self.rect.move_ip(0,5) #Y axis movement at 5 px per frame self.angle += 5 #add 5 anglewhen the rect has not hit one of the window self.angle %= 360 if self.rect.left < 0 or self.rect.right > self.width: self.speed[0] = -self.speed[0] self.angle = -self.angle #tried to invert the angle self.angle -= 5 #trying to negate the angle rotation self.angle %= 360 self.screen.blit(self.rotate_image(),self.rect) pygame.display.flip() I would really like to know how to invert rotation of a image. You may provide your own examples.

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• Trying to create a group of button sprites

  - by user1449653

  Good day, I have like 15 images I need to be buttons. I have buttons working with a Box() (Box - looks like this) class Box(pygame.sprite.Sprite): def __init__(self): pygame.sprite.Sprite.__init__(self) self.image = pygame.Surface((35, 30)) self.image = self.image.convert() self.image.fill((255, 0, 0)) self.rect = self.image.get_rect() self.rect.centerx = 25 self.rect.centery = 505 self.dx = 10 self.dy = 10 I am trying to make the buttons work with image sprites. So I attempted to copy the class style of the box and do the same for my Icons.. code looks like this... class Icons(pygame.sprite.Sprite): def __init__(self): pygame.sprite.Sprite.__init__(self) self.image = pygame.image.load("images/airbrushIC.gif").convert() self.rect = self.image.get_rect() self.rect.x = 25 self.rect.y = 550 the code in the main() rect = image.get_rect() rect.x = 25 rect.y = 550 ic1 = Icons((screen.get_rect().x, screen.get_rect().y)) screen.blit(ic1.image, ic1.rect) pygame.display.update() This code produces a positional (accepts 1 argument but 2 are there) error or an image is not referenced error (inside the Icon class). I'm unsure if this is the right way to go about this anyways.. I know for sure that I need to load all the images (as sprites)... store them in an array... and then have my mouse check if it is clicking one of the items in the array using a for loop. Thanks. EDIT QUESTION 2: class Icons(pygame.sprite.Sprite): def init(self, *args): pygame.sprite.Sprite.init(self, *args) self.image = pygame.image.load("images/airbrushIC.gif").convert() self.rect = self.image.get_rect() ic1 = self.image self.rect.x = 10 self.rect.y = 490 self.image = pygame.image.load("images/fillIC.gif").convert() self.rect = self.image.get_rect() ic2 = self.image self.rect.x = 10 self.rect.y = 540 Thanks to your help I got the Icons class loading ONE image. Its not loading both. Obviously because its being overwritten by the second one. It seems that "class" for this purpose isn't what I need. Which begs the question how I make sprites outside of a class.. If there is a way to make the class work please let me know.

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• Python & Pygame: Updating all elements in a list under a loop during iteration

  - by Unit978

  i am working on a program in Python and using Pygame. this is what the basic code looks like: while 1: screen.blit(background, (0,0)) for event in pygame.event.get(): if event.type == QUIT: pygame.quit() sys.exit() if event.type == KEYDOWN and event.key == K_c: circle_create = True circle_list.append(Circle()) if event.type == MOUSEBUTTONDOWN and circle_create == True: if clicks == 0: circle_list[i].center() clicks += 1 if event.type == MOUSEMOTION and clicks == 1 and circle_create == True: circle_list[i].stretch() these if statements are under the while loop not the for loop since they dont require input from the user if circle_create == True: circle_list[i].draw_circle() if clicks == 2: clicks = 0 i += 1 circle_create = False pygame.display.update() what i want to do is have the object's function of draw_circle() to be constantly updated by the loop so that the drawn circle is shown for all objects in the list, but since the list is iterated it updates the new object added and the objects already appended are not updated. The program, works, it draws the circles upon user input but the update problem is the only issue i need to solve. Is there any possible way to have all elements in the list of objects being updated by the while loop? i have tried for many days and i have not been able to find a good solution. any ideas are appreciated. Thanks

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• Windows splash screen using GDI+

  - by Luther

  The eventual aim of this is to have a splash screen in windows that uses transparency but that's not what I'm stuck on at the moment. In order to create a transparent window, I'm first trying to composite the splash screen and text on an off screen buffer using GDI+. At the moment I'm just trying to composite the buffer and display it in response to a 'WM_PAINT' message. This isn't working out at the moment; all I see is a black window. I imagine I've misunderstood something with regards to setting up render targets in GDI+ and then rendering them (I'm trying to render the screen using straight forward GDI blit) Anyway, here's the code so far: //my window initialisation code void MyWindow::create_hwnd(HINSTANCE instance, const SIZE &dim) { DWORD ex_style = WS_EX_LAYERED ; //eventually I'll be making use of this layerd flag m_hwnd = CreateWindowEx( ex_style, szFloatingWindowClass , L"", WS_POPUP , 0, 0, dim.cx, dim.cy, null, null, instance, null); SetWindowLongPtr(m_hwnd ,0, (__int3264)(LONG_PTR)this); m_display_dc = GetDC(NULL); //This was sanity check test code - just loading a standard HBITMAP and displaying it in WM_PAINT. It worked fine //HANDLE handle= LoadImage(NULL , L"c:\\test_image2.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); m_gdip_offscreen_bm = new Gdiplus::Bitmap(dim.cx, dim.cy); m_gdi_dc = Gdiplus::Graphics::FromImage(m_gdip_offscreen_bm);//new Gdiplus::Graphics(m_splash_dc );//window_dc ;m_splash_dc //this draws the conents of my splash screen - this works if I create a GDI+ context for the window, rather than for an offscreen bitmap. //For all I know, it might actually be working but when I try to display the contents on screen, it shows a black image draw_all(); //this is just to show that drawing something simple on the offscreen bit map seems to have no effect Gdiplus::Pen pen(Gdiplus::Color(255, 0, 0, 255)); m_gdi_dc->DrawLine(&pen, 0,0,100,100); DWORD last_error = GetLastError(); //returns '0' at this stage } And here's the snipit that handles the WM_PAINT message: ---8<----------------------- //Paint message snippit case WM_PAINT: { BITMAP bm; PAINTSTRUCT ps; HDC hdc = BeginPaint(vg->m_hwnd, &ps); //get the HWNDs DC HDC hdcMem = vg->m_gdi_dc->GetHDC(); //get the HDC from our offscreen GDI+ object unsigned int width = vg->m_gdip_offscreen_bm->GetWidth(); //width and height seem fine at this point unsigned int height = vg->m_gdip_offscreen_bm->GetHeight(); BitBlt(hdc, 0, 0, width, height, hdcMem, 0, 0, SRCCOPY); //this blits a black rectangle DWORD last_error = GetLastError(); //this was '0' vg->m_gdi_dc->ReleaseHDC(hdcMem); EndPaint(vg->m_hwnd, &ps); //end paint return 1; } ---8<----------------------- My apologies for the long post. Does anybody know what I'm not quite understanding regarding how you write to an offscreen buffer using GDI+ (or GDI for that matter)and then display this on screen? Thank you for reading.

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