Brightness/contrast shader don't work on other PC. Shader problem! (SOLVED)

Questions
#1

Hello, everyone!

I’m totally new to shaders, but with a huge help of defold forum managed to copy and adapt that brightness/contrast shader from ShaderToy. So it works perfect on my main (win 10) PC, but once I’ve copied windows bundle to (win 10) laptop, it refused to work with:

WARNING:GRAPHICS 0:4 #version direction missing
ERROR: 0:47: “=” : cannot convert from ‘4 component vector of highp float’ to ‘highp float’

and then there go a few lines of ‘unable to create resource’ errors

Here’s a tiny shader I use:

varying mediump vec2 var_texcoord0;
varying mediump vec3 var_position;

uniform lowp sampler2D sbuffer;
uniform lowp vec4 tint;
uniform lowp vec4 bcs;

mat4 brightnessMatrix( float brightness ) {
	return mat4( 1, 0, 0, 0,
		0, 1, 0, 0,
		0, 0, 1, 0,
		brightness, brightness, brightness, 1 );
	}

mat4 contrastMatrix( float contrast ) {
	float t = ( 1.0 - contrast ) / 2.0;
	return mat4( contrast, 0, 0, 0,
		0, contrast, 0, 0,
		0, 0, contrast, 0,
		t, t, t, 1 );
	}

mat4 saturationMatrix( float saturation ) {
		vec3 luminance = vec3( 0.3086, 0.6094, 0.0820 );

		float oneMinusSat = 1.0 - saturation;
		vec3 red = vec3( luminance.x * oneMinusSat );
		red+= vec3( saturation, 0, 0 );
		vec3 green = vec3( luminance.y * oneMinusSat );
		green += vec3( 0, saturation, 0 );
		vec3 blue = vec3( luminance.z * oneMinusSat );
		blue += vec3( 0, 0, saturation );
		return mat4 ( red,     0,
			green,   0,
			blue,    0,
			0, 0, 0, 1 );
	}

void main() {
	float brightness = bcs.x;
	float contrast = bcs.y;
	float saturation = bcs.z;
	lowp vec4 tint_pm = vec4(tint.xyz * tint.w, tint.w);
	vec4 color = texture2D(sbuffer, var_texcoord0.xy);
	float grey = color; //color.r * 0.3 + color.g * 0.59 + color.b * 0.11;
	gl_FragColor = brightnessMatrix( brightness ) * contrastMatrix( contrast ) * saturationMatrix( saturation ) * color * tint_pm;
}

I know that the problem it that I’m total noob with shaders. But I just don’t know where to go with this.
Hege thanks for any possible help!

#2

This problem is not related to your hardware or Windows version. It might work on some forgiven OpenGL versions but you have to fix it.

Error points the line 47. Which is:

grey is float, color is vec4. You are trying to define vector 4 to float. This is not possible.
Float is 0.0 and vector 4 is (0.0, 0.0, 0.0, 0.0).
Don’t know how the original shadertoy example works but maybe you shoud uncomment the line:

float grey =  color.r * 0.3 + color.g * 0.59 + color.b * 0.11;
3 Likes
#3

OMG! Im so dumb.
It’s a redundant line form the original code I’ve missed. Huge thanks!

And thanks for explaining those floats and vec4 too.

2 Likes