[libcamera-devel] [PATCH v5 1/9] qcam: viewfinder_gl: change uniform float tex_stepx to vec2 tex_step

[Laurent Pinchart]

Hi Andrey,

Thank you for the patch.

On Tue, Jun 22, 2021 at 04:46:44PM +0300, Andrey Konovalov wrote:
> In preparation to extend the supported formats, extend the tex_stepx
> uniform to cover the steps between texels in both horizontal and
> vertical directions.
> 
> Signed-off-by: Andrey Konovalov <andrey.konovalov at linaro.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  src/qcam/assets/shader/YUV_packed.frag | 8 ++++----
>  src/qcam/viewfinder_gl.cpp             | 7 ++++---
>  src/qcam/viewfinder_gl.h               | 2 +-
>  3 files changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/src/qcam/assets/shader/YUV_packed.frag b/src/qcam/assets/shader/YUV_packed.frag
> index 224dfafe..d6efd4ce 100644
> --- a/src/qcam/assets/shader/YUV_packed.frag
> +++ b/src/qcam/assets/shader/YUV_packed.frag
> @@ -12,7 +12,7 @@ precision mediump float;
>  varying vec2 textureOut;
>  
>  uniform sampler2D tex_y;
> -uniform float tex_stepx;
> +uniform vec2 tex_step;
>  
>  void main(void)
>  {
> @@ -49,10 +49,10 @@ void main(void)
>  	 * a = fract(x) * 2 - 1			if fract(x) >= 0.5
>  	 */
>  	vec2 pos = textureOut;
> -	float f_x = fract(pos.x / tex_stepx);
> +	float f_x = fract(pos.x / tex_step.x);
>  
> -	vec4 left = texture2D(tex_y, vec2(pos.x - f_x * tex_stepx, pos.y));
> -	vec4 right = texture2D(tex_y, vec2(pos.x + (1.0 - f_x) * tex_stepx , pos.y));
> +	vec4 left = texture2D(tex_y, vec2(pos.x - f_x * tex_step.x, pos.y));
> +	vec4 right = texture2D(tex_y, vec2(pos.x + (1.0 - f_x) * tex_step.x , pos.y));
>  
>  #if defined(YUV_PATTERN_UYVY)
>  	float y_left = mix(left.g, left.a, f_x * 2.0);
> diff --git a/src/qcam/viewfinder_gl.cpp b/src/qcam/viewfinder_gl.cpp
> index 5d9b442e..ff719418 100644
> --- a/src/qcam/viewfinder_gl.cpp
> +++ b/src/qcam/viewfinder_gl.cpp
> @@ -289,7 +289,7 @@ bool ViewFinderGL::createFragmentShader()
>  	textureUniformY_ = shaderProgram_.uniformLocation("tex_y");
>  	textureUniformU_ = shaderProgram_.uniformLocation("tex_u");
>  	textureUniformV_ = shaderProgram_.uniformLocation("tex_v");
> -	textureUniformStepX_ = shaderProgram_.uniformLocation("tex_stepx");
> +	textureUniformStep_ = shaderProgram_.uniformLocation("tex_step");
>  
>  	/* Create the textures. */
>  	for (std::unique_ptr<QOpenGLTexture> &texture : textures_) {
> @@ -508,8 +508,9 @@ void ViewFinderGL::doRender()
>  		 * ([0, 1]). There are exactly width - 1 steps between the
>  		 * leftmost and rightmost texels.
>  		 */
> -		shaderProgram_.setUniformValue(textureUniformStepX_,
> -					       1.0f / (size_.width() / 2 - 1));
> +		shaderProgram_.setUniformValue(textureUniformStep_,
> +					       1.0f / (size_.width() / 2 - 1),
> +					       1.0f /* not used */);
>  		break;
>  
>  	case libcamera::formats::ABGR8888:
> diff --git a/src/qcam/viewfinder_gl.h b/src/qcam/viewfinder_gl.h
> index 150fa4ae..1b1faa91 100644
> --- a/src/qcam/viewfinder_gl.h
> +++ b/src/qcam/viewfinder_gl.h
> @@ -85,7 +85,7 @@ private:
>  	GLuint textureUniformU_;
>  	GLuint textureUniformV_;
>  	GLuint textureUniformY_;
> -	GLuint textureUniformStepX_;
> +	GLuint textureUniformStep_;
>  	unsigned int horzSubSample_;
>  	unsigned int vertSubSample_;
>  

-- 
Regards,

Laurent Pinchart