Messages

1

Graphics / Can a RenderTexture be resized?

« on: February 22, 2019, 05:14:44 pm »

Hey guys!

I have a dynamic width requirement for a sprite generated from a RenderTexture, but redundant calls to rt.create don't seem to reinitialize it to the new width ( apparently I'm not supposed to do it this way )

Is there a proper way to destroy and recreate a RenderTexture?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Basically I've created a custom font class that makes a single sprite out of a line of text, but only when the text changes.  If I call create redundantly, I see graphical artifacts at the edge of my sprite, which tells me the texture probably didn't resize.  Hopefully there is a better solution than creating the render texture once to the entire width of the window (since I may have dozens of these objects)

This is what I'm doing when the text changes..

rt.create( width, height);

rt.clear( sf::Color( 0,0,0,0));

DrawText( pszString, rshader, tint);

rt.display();

textureText = rt.getTexture();
      
spriteText.setTexture( textureText);

Any feedback is appreciated, thank you!!

2

Window / Re: Window resizing?

« on: November 17, 2015, 01:50:43 am »

Perfect, thank you Laurent!  I was having the same problem.

3

Graphics / Re: Problem manipulating gl_FragColor in my fragment shader

« on: November 09, 2015, 06:37:35 pm »

Thank you Laurent!

I did figure out at the end that I needed to acquire the color from the texture with a call to texture2D.   I should not be coding at 4:00 in the morning

4

Graphics / Problem manipulating gl_FragColor in my fragment shader

« on: November 09, 2015, 10:15:14 am »

Hey all, I'm kind of stuck on something.  Any help would be appreciated!

I'm trying to convert a game I wrote in XNA to SFML and I'm having difficulty porting an HLSL pixel shader I wrote over to GLSL.  It should be a simple thing but somehow I'm not getting the desired output.

Basically, I want to render a sprite with transparency, but setting the non-transparent pixels to a passed value so that it might appear solid-color like so :



My sprites load and display correctly under the default shader, but somehow what I'm writing ignores the alpha channel or I am not doing an operation correctly, I don't know.

My shader.frag looks like so:

uniform vec4 indexColor;

void main()
{

        if( gl_FragColor.a > 0.01) // set color to passed value
        {
                gl_FragColor = indexColor;
                gl_FragColor.a = 1.0;
        }
        else // otherwise do not render this pixel
        {
                gl_FragColor = 0;
        }

}

This particular code renders everything transparent, so somehow I'm not evaluating the alpha channel correctly.

My code is calls this once per update:

window.clear( sf::Color( COLOR_BLACK));

shader.setParameter("texture", sf::Shader::CurrentTexture);

Then in my loop, for each sprite I call :

shader.setParameter("indexColor", sf::Color( 1.0f, 0.8f, 0.6f, 1.0f));

window.draw( sprite, &shader);

I do know the shader is loading because I can force it to draw everything a solid color.  Any ideas?  Thanks!

EDIT :

As per usual I may have resolved my own question, sorry!

I got it to work with this shader :

uniform sampler2D texture;

uniform float r;
uniform float g;
uniform float b;

void main()
{
        vec4 pixel = texture2D(texture, gl_TexCoord[0].xy);

   
        if( pixel.a > 0.1)
        {
                pixel.r = r;
                pixel.g = g;
                pixel.b = b;

                pixel.a = 1.0;

                gl_FragColor = pixel;
        }
        else
        {
                gl_FragColor = vec4( 1.0, 1.0, 0.0, 0.0);
        }
}

I'm sure I don't need to pass the RGB individually but it works for now.