I've got following code from Lazy:
#include <iostream>
#include "SDL/SDL.h"
using namespace std;
int main()
{
//Start SDL
SDL_Init(SDL_INIT_EVERYTHING);
SDL_Surface *hello = NULL;
SDL_Surface *screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);
hello = SDL_LoadBMP("hello.bmp");
SDL_BlitSurface(hello, NULL, screen, NULL);
SDL_Flip(screen);
SDL_Delay(3000);
SDL_FreeSurface(hello);
//Quit SDL
SDL_Quit();
return 0;
}
From time to time the picture is shown, but most of time it's just a black window (with slim string of this picture). And I've got the BMP file with name "hello.bmp" in the same directory.
PS.I've got ArchLinux.
Before displaying your image you should convert it to a format compatible to the video mode you selected.
Therefore you should implement something like this:
SDL_Surface *imagef;
imagef = SDL_DisplayFormat(image);
Before bliting your BMP and use imagef for all of your operations.
Related
as title, I'm having problems trying to make SDL2 display frames from realsesense pipeline. I have no clue how to extract data from the frameset and process it in order to make it works with SDL2. I'm programming in C++. I've read all the documentation on Intel SDK website and tried a lot of different approches, nothing worked so far.
Here's some code I've wrote on a new project:
int main(int argc, char * argv[])
{
window window(1280, 720, "Tecnos Depth Cam Demo");
rs2::colorizer color_map;
rs2::pipeline pipe;
pipe.start();
while (true)
{
rs2::frameset data = pipe.wait_for_frames().apply_filter(color_map);
// Process data to work with SDL2 renderer (my problem)
}
}
At the end I managed to do it. Simply create a texture with SDL_CreateTexture and update it with the pixels data from get_data() function of Realsense library each frame. The tricky part is that you have to define a pixel format with:
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED8, SDL_PACKEDORDER_XBGR, SDL_PACKEDLAYOUT_8888, BITS_PER_PIXEL, BYTES_PER_PIXEL)
Here a little code demo that I wrote on porpuse to show you:
#include <iostream>
#define SDL_MAIN_HANDLED
#include <SDL.h>
#include <librealsense2/rs.hpp>
#define WINDOW_WIDTH 1280
#define WINDOW_HEIGHT 720
#define BITS_PER_PIXEL 24
#define BYTES_PER_PIXEL 3
int main(int argc, char* argv[])
{
// Init
SDL_Init(SDL_INIT_EVERYTHING);
// Declarative section
SDL_Window* window = SDL_CreateWindow("Tutorial", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, WINDOW_WIDTH, WINDOW_HEIGHT, SDL_WINDOW_ALLOW_HIGHDPI);
SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
SDL_Texture* textureCamera = SDL_CreateTexture(renderer, SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED8, SDL_PACKEDORDER_XBGR, SDL_PACKEDLAYOUT_8888, BITS_PER_PIXEL, BYTES_PER_PIXEL), SDL_TEXTUREACCESS_TARGET, WINDOW_WIDTH, WINDOW_HEIGHT);
rs2::pipeline camera;
rs2::frameset frames;
// Executive section
camera.start();
// Loop
while (true)
{
// Do whatever you like there
SDL_RenderClear(renderer);
// ...
frames = camera.wait_for_frames();
Uint8* pixels = (Uint8*)(frames.get_color_frame().get_data());
SDL_UpdateTexture(textureCamera, NULL, pixels, frames.get_color_frame().get_bytes_per_pixel() * WINDOW_WIDTH);
SDL_RenderCopy(renderer, textureCamera, NULL, NULL);
SDL_RenderPresent(renderer);
}
return EXIT_SUCCESS;
}
I hope I helped someone in trouble like me. For any question just ask me, I'll be more than happy to help! Lastly thanks to the stackoverflow community to always help even when it doesn't!
I have been trying to make a PNG image appear on-screen to my SDL window. I am using the Eclipse CDT. SDL.h and SDL_image.h both seem to have been correctly linked, in that the functions pop up with colour on the compiler. When I run my code, however, literally nothing happens. There are no errors in the compiler, no comments, nothing. The window doesn't appear. I would really appreciate if anyone could help me out on the matter.
Also, SDL has worked previously on my computer before (without using SDL_image) - in which I ran a particle simulation that worked perfectly fine.
My code:
#include <iostream>
#include "SDL.h"
#include "SDL_image.h"
using namespace std;
SDL_Window *m_window; //Window upon which the game will be displayed.
SDL_Renderer *m_renderer; //Renderer used to draw the objects on the window.
SDL_Texture *playerTex;
int SCREEN_WIDTH = 600;
int SCREEN_HEIGHT = 600;
int main(int argc, char* args[]) {
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
cout << "Video init failed" << endl;
return 1;
}
//Creates the actual SDL-window and stores it in the m_window variable.
m_window = SDL_CreateWindow("Marko Beocanin SDD Project",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT,
SDL_WINDOW_FULLSCREEN);
//Error-checking method that determines if SDL could not create a window - returns false if unsuccessful.
if (m_window == NULL) {
cout << "Window Creation failed" << endl;
SDL_Quit();
IMG_Quit();
return 2;
}
//Creates an SDL-Renderer: a tool used to actually draw objects on the Window
m_renderer = SDL_CreateRenderer(m_window, -1, 0);
//Error-checking method that determines if SDL could not create a renderer - returns false if unsuccessful.
if (m_renderer == NULL) {
cout << "Renderer creation failed." << endl;
SDL_DestroyWindow(m_window);
SDL_Quit();
IMG_Quit();
return 3;
}
SDL_Surface *tmpSurface = IMG_Load("img.png");
playerTex = SDL_CreateTextureFromSurface(m_renderer, tmpSurface);
SDL_FreeSurface(tmpSurface);
SDL_RenderClear(m_renderer);
SDL_RenderCopy(m_renderer, playerTex, NULL, NULL);
SDL_RenderPresent(m_renderer);
SDL_Delay(2000);
SDL_DestroyWindow(m_window);
SDL_Quit();
IMG_Quit();
return 0;
}
The problem I had was a result of me using the wrong SDL_image library - I was using x64 instead of x86, which meant that it didn't throw an error per se, just didn't work properly!
IDE: Code::blocks
Compiler: MinGW
I have SDL and SDL_image installed correctly (it doesn't give any errors when built).
Everything compiles fine but when I run it, the SDL window comes up, but the image never blits, the window. I use SDL_image so I can load PNG images (or so I'm hoping).
The code:
#include <cstdlib>
#include <iostream>
#include "SDL_image.h"
#include <SDL/SDL.h>
int main ( int argc, char** argv )
{
SDL_Surface* test = NULL;
SDL_Surface* screen = NULL;
//Start SDL
SDL_Init( SDL_INIT_EVERYTHING );
//Name the window
SDL_WM_SetCaption( "Test-1", NULL );
//Set up screen
screen = SDL_SetVideoMode( 640, 480, 32, SDL_SWSURFACE );
//Load image
test = IMG_Load("Test.png");
//Apply image to screen
SDL_BlitSurface( test, NULL, screen, NULL );
//Update Screen
SDL_Flip( screen );
//Pause
SDL_Delay( 2000 );
//Free the loaded image
SDL_FreeSurface( test );
//Quit SDL
SDL_Quit();
return 0;
}
Maybe you could try creating a window and then a surface and then blit the image onto the window through the surface? Then you can try with this function:
SDL_UpdateWindowSurface(*windowinstance*)
More information here: link (although this is loading a *.bmp file, but I'm sure the concept is the same). Also try the above mentioned answer also. Might be just that the image cannot be found...
So I'm trying to display a simply image with the SDL library, but when I use the function SDL_BlitSurface() nothing happens, and all I get is a black screen. I should also note that I have the .bmp file, the source, and the executable file all in the same directory.
//SDL Header
#include "SDL/SDL.h"
int main(int argc, char* args[])
{
//Starts SDL
SDL_Init(SDL_INIT_EVERYTHING);
//SDL Surfaces are images that are going to be displayed.
SDL_Surface* Hello = NULL;
SDL_Surface* Screen = NULL;
//Sets the size of the window (Length, Height, Color(bits), Sets the Surface in Software Memory)
Screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);
//Loads a .bmp image
Hello = SDL_LoadBMP("Hello.bmp");
//Applies the loaded image to the screen
SDL_BlitSurface(Hello, NULL, Screen, NULL);
//Update Screen
SDL_Flip(Screen);
//Pause
SDL_Delay(2000);
//Deletes the loaded image from memory
SDL_FreeSurface(Hello);
//Quits SDL
SDL_Quit();
return 0;
}
LoadBMP() is crap. Install SDL_image library
sudo apt-get install SDL_image SDL_image_dev
(not sure about the names of the packages. Just use aptitude or synaptic or whatever to find them)
and include it with
#include "SDL_image.h"
You load your image then with
SDL_Surface* Hello = IMG_Load("Hello.bmp");
if (!Hello){
printf("Ooops, something went wrong: %s\n", IMG_GetError());
exit(0);
}
Important: Note that you should always do an error check and print out the error.
if (!Hello) is the same as if (Hello == NULL)
have you tried blitting any other types of images? when I first started SDL I remember having issues with .bmp files. Try a .jpg or .png and get back to me whether your code works or not.
I had similar "Problems"; maybe it's a pre-Version, or version incompatible to your graphic-driver; let's figure out. SWSurface and Flip; as I remember, the Flip-functionality only works with double-buffered HW_Surface.
Screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);
Please try Update instead of Flip.
SDL_Update(surface);
And nexttime :)
Hello = SDL_LoadBMP("Hello.bmp");
if(Hello != NULL) {
//Applies the loaded image to the screen
SDL_BlitSurface(Hello, NULL, Screen, NULL);
//Update Screen
...
//Deletes the loaded image from memory
SDL_FreeSurface(Hello);
}
because SDL_FreeSurface(NULL) will crash your programm.
I'm attemting to load an image that I exported from flash CS3 it's a very cute face but it loads very weird it loads on a blueish way this is the code for the two files:
//main.cpp
#include <SDL/SDL.h>
#include <SDL/SDL_image.h>
#include "test.hpp"
int main(int argc, char *argv[])
{
SDL_Init(SDL_INIT_VIDEO);
// Activamos modo de video
screen = SDL_SetVideoMode(640,480,32,SDL_SWSURFACE | SDL_DOUBLEBUF);
image = IMG_Load("face.bmp");
dest.x = 200;
dest.y = 200;
//Main Loop
while(Abierto)
{
//We Draw
Draw();
//Events
while( SDL_PollEvent(&event))
{
if(event.type == SDL_QUIT)
Abierto = false;
}
}
// We free the image
SDL_FreeSurface(image);
SDL_Quit();
return 0;
}
Now the other one the;
//test.hpp
DL_Surface *image = NULL, *screen = NULL;
SDL_Rect dest;
SDL_Event event;
bool Abierto = true;
float PlaneX = 300, PlaneY = 200;
float velX = 0.1, velY = 0.1;
void Draw()
{
Uint32 color;
// Black Background is created
color = SDL_MapRGB (screen -> format, 0, 0, 0);
SDL_FillRect (screen, NULL, color);
SDL_DisplayFormatAlpha(image);
SDL_BlitSurface(image, NULL, screen, &dest);
// Flip the working image buffer with the screen buffer
SDL_Flip (screen);
}
I need help with this please Im not that experienced on SDL stuff oh and if you want to take a closer look I uplaoded the project here.
Oh my bad I must add the image is 32 pixels with alpha according to flash exporting options
According to docs, SDL_DisplayFormatAlpha returns a new image and keeps the original intact.
So, try in the first part, when you load the image:
SDL_Surface *origImage = IMG_Load("face.bmp");
image = SDL_DisplayFormatAlpha(origImage);
SDL_FreeSurface(origImage)
As there is no need to call SDL_DisplayFormatAlpha each frame.
Then in the second part, just blit image, without calling SDL_DisplayFormatAlpha.
UPDATE
I've just checked your picture, and it looks like it is a weird bmp. I've seen that before: BMP format is such a mess that if you don't keep to the basics chances are that different programs will interpret the data differently.
In your case:
display face.bmp shows correctly.
gthumb face.bmp shows nothing.
eog face.bmp says "bogus header data".
I strongly recommend using PNG files for all your game cartoon-like pictures and JPG for all the photo-like ones.
So run
$ convert face.bmp face.png
And use the PNG file. I'll will work better and you will have a file 20% the size of the original.