Question

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

Answer 1

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.