HQ2X Shader lost when changing Fullscreen / Windowed mode [Solved]

[Marskilla]

Hi, here is another problem I found in FS-UAE (correction have been made with this thread) so I keep reporting bugs I find.

Here is a configuration file

[config]
amiga_model = A500
kickstart_file = Kickstart v1.3 rev 34.5 (1987)(Commodore)(A500-A1000-A2000-CDTV).zip
kickstarts_dir = .\kickstarts\
window_width = 752
window_height = 572
fsaa = 4
keep_aspect = 1
video_sync_method = finish-swap-finish
floppies_dir = .\floppies\
chip_memory = 1024
slow_memory = 512
fast_memory = 4096
keyboard_key_lctrl = action_joy_1_fire_button
fullscreen_mode = fullscreen-window
shader = HQ2x.OpenGL.shader

this config use this shader (HQ2X)

<?xml version="1.0" encoding="UTF-8"?>
<shader language="GLSL">
  <vertex><![CDATA[
    uniform vec2 rubyTextureSize;

    void main() {
      float x = 0.5 * (1.0 / rubyTextureSize.x);
      float y = 0.5 * (1.0 / rubyTextureSize.y);
      vec2 dg1 = vec2( x, y);
      vec2 dg2 = vec2(-x, y);
      vec2 dx = vec2(x, 0.0);
      vec2 dy = vec2(0.0, y);

      gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
      gl_TexCoord[0] = gl_MultiTexCoord0;
      gl_TexCoord[1].xy = gl_TexCoord[0].xy - dg1;
      gl_TexCoord[1].zw = gl_TexCoord[0].xy - dy;
      gl_TexCoord[2].xy = gl_TexCoord[0].xy - dg2;
      gl_TexCoord[2].zw = gl_TexCoord[0].xy + dx;
      gl_TexCoord[3].xy = gl_TexCoord[0].xy + dg1;
      gl_TexCoord[3].zw = gl_TexCoord[0].xy + dy;
      gl_TexCoord[4].xy = gl_TexCoord[0].xy + dg2;
      gl_TexCoord[4].zw = gl_TexCoord[0].xy - dx;
    }
  ]]></vertex>

  <fragment filter="linear"><![CDATA[
    uniform sampler2D rubyTexture;

    const float mx = 0.325;      // start smoothing wt.
    const float k = -0.250;      // wt. decrease factor
    const float max_w = 0.25;    // max filter weigth
    const float min_w =-0.05;    // min filter weigth
    const float lum_add = 0.25;  // effects smoothing

    void main() {
      vec3 c00 = texture2D(rubyTexture, gl_TexCoord[1].xy).xyz; 
      vec3 c10 = texture2D(rubyTexture, gl_TexCoord[1].zw).xyz; 
      vec3 c20 = texture2D(rubyTexture, gl_TexCoord[2].xy).xyz; 
      vec3 c01 = texture2D(rubyTexture, gl_TexCoord[4].zw).xyz; 
      vec3 c11 = texture2D(rubyTexture, gl_TexCoord[0].xy).xyz; 
      vec3 c21 = texture2D(rubyTexture, gl_TexCoord[2].zw).xyz; 
      vec3 c02 = texture2D(rubyTexture, gl_TexCoord[4].xy).xyz; 
      vec3 c12 = texture2D(rubyTexture, gl_TexCoord[3].zw).xyz; 
      vec3 c22 = texture2D(rubyTexture, gl_TexCoord[3].xy).xyz; 
      vec3 dt = vec3(1.0, 1.0, 1.0);

      float md1 = dot(abs(c00 - c22), dt);
      float md2 = dot(abs(c02 - c20), dt);

      float w1 = dot(abs(c22 - c11), dt) * md2;
      float w2 = dot(abs(c02 - c11), dt) * md1;
      float w3 = dot(abs(c00 - c11), dt) * md2;
      float w4 = dot(abs(c20 - c11), dt) * md1;

      float t1 = w1 + w3;
      float t2 = w2 + w4;
      float ww = max(t1, t2) + 0.0001;

      c11 = (w1 * c00 + w2 * c20 + w3 * c22 + w4 * c02 + ww * c11) / (t1 + t2 + ww);

      float lc1 = k / (0.12 * dot(c10 + c12 + c11, dt) + lum_add);
      float lc2 = k / (0.12 * dot(c01 + c21 + c11, dt) + lum_add);

      w1 = clamp(lc1 * dot(abs(c11 - c10), dt) + mx, min_w, max_w);
      w2 = clamp(lc2 * dot(abs(c11 - c21), dt) + mx, min_w, max_w);
      w3 = clamp(lc1 * dot(abs(c11 - c12), dt) + mx, min_w, max_w);
      w4 = clamp(lc2 * dot(abs(c11 - c01), dt) + mx, min_w, max_w);

      gl_FragColor.xyz = w1 * c10 + w2 * c21 + w3 * c12 + w4 * c01 + (1.0 - w1 - w2 - w3 - w4) * c11;
    }
  ]]></fragment>
</shader>

When the emulateur starts, the shader is active :

(nice... )

If the emulator is switched to full screen, the shader is lost. Furthermore, it doesn't get back when you return to windowed mode :

(not so nice... )

Maybe it's because of the parameter in the config file ?

fullscreen_mode = fullscreen-window

But when I start with

fullscreen = 1

The shader is active in fullscreen (but disappear when I switch to windowed mode).

I tested with the bundled "curavture" shader, it does the same thing.

[FrodeSolheim]

Hi, I haven't checked yet, but most likely the shaders are not reloaded properly after fullscreen/window switch (the OpenGL context is re-created by SDL when toggling fullscreen, so OpenGL stuff must be reloaded). I'll fix it, of course

Btw, for pixel enhancement shaders such as HQ2X, you'll probably get nicer results by forcing low resolution output, so pixels are not already doubled in width and height before processed by the shader:

line_doubling = 0
low_resolution = 1

[Marskilla]

Originally Posted by FrodeSolheim

Btw, for pixel enhancement shaders such as HQ2X, you'll probably get nicer results by forcing low resolution output, so pixels are not already doubled in width and height before processed by the shader:

line_doubling = 0
low_resolution = 1

Indeed !
Here are the results

• "out of the box"
• with the HQ2x filter /with low resolution / without line doubling

[FrodeSolheim]

I have fixed it so the shaders are re-initialized when the switching between windowed<->fullscreen.
Windows binaries here: http://fengestad.no/fs-uae/files/1.3.27u1/

Please give it a try

[Marskilla]

It works perfectly now...

Nothing to add !