canysway dev blog

Mosaic effect is similar to lowering the resolution of an image. Let's see example image. And full source code likes below. void mainImage( out vec4 fragColor, in vec2 fragCoord ){     // Normalized pixel coordinates (from 0 to 1)     vec2 uv = fragCoord/iResolution.xy;     if (uv.x > 0.7 && uv.y < 0.4 ){          //left bottoom small image         uv.x -= 0.6 ;         uv *= 2.0 ;         fragColor = texture (iChannel0, uv);         fragColor += vec4 ( 0.2 );         return ;     }     //mosaic effect     uv = uv * 30.0 ;     vec2 uv = floor (uv);     uv = uv/ 30.0 ;     fragColor = texture (iChannel0, uv); } The key function of mosaic effect is "floor" If you want to make it sharper, multiply uv by ...

How can we devide camera view like above image? If you think adjusting the position and size by dividing each section, it will be a very difficult task. And If you made it that way, how can you make the following 10x10 image? The answer is "T o make pattern,  Use fract function." The full code is like below.  If you want to make 4x4 image, change this line : " uv *= 4.0; " void mainImage( out vec4 fragColor, in vec2 fragCoord ){     // Normalized pixel coordinates (from 0 to 1)     vec2 uv = fragCoord/iResolution.xy;     uv *= 10.0 ;     uv = fract (uv);     fragColor = texture (iChannel0, uv); } Declaration genType fract ( genType x ) Description returns the fractional part of  x . This is calculated as  x  -  floor ( x ). reference (  https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/fract.xhtml ) - Before fract fun...

Translate, rotate and scale are most basic element of image effect. If you didn't understand how make effect at each pixel, please read again before post "Show Video and Image" . 1. Translate Translation means each pixel move parallel on the x, y-axis. In other words, if you want to translate 0.25 on the x-axis, a pixel should point to a distance of -0.25 from the original. Translate ex) void mainImage( out vec4 fragColor, in vec2 fragCoord ){     vec2 uv = fragCoord/iResolution.xy;     if (uv.x < 0.5 ){         // translate to x ( -0.25 )         uv.x += 0.25 ;     } else {         // translate to x ( +0.25 )         uv.x -= 0.25 ;     }     fragColor = texture (iChannel0, uv); } result) 2. Scale Scale also has a  similar concept to parallel translation. If you want to zoom in twice, each pixel s...

The simple image is made like this. void  mainImage(  out   vec4  fragColor,  in   vec2  fragCoord ){      // Normalized pixel coordinates (from 0 to 1)      vec2  uv = fragCoord/iResolution.xy;           //uv.x = uv.x - 0.3;      fragColor =  texture (iChannel0, uv); } I think GPU processing has two major steps. Normalizing and Pointing. 1. Normalizing Each pixel has screen coordinate and we need to normalizing from 0.0 to 1.0, because there are many displays with various resolutions around us. We can not manage it at each resolution. It is very troublesome. So we should normalize it :   vec2   uv = fragCoord/iResolution.xy; 2. Pointing I told you each pixel has a screen coordinate. At each coordinate we need to link with sampler's coordinate. Sampler has also coordinate 0.0 to 1.0. As a result, we see the samplers p...

GLSL (OpenGL Shading Language)   is a language that enables developers to directly control the graphics pipeline.  We will do GPU programming using GLSL.  And I recommend the Shadertoy to easily program it. By using Shadertoy, y ou can see the results of GLSL programming on the screen without OpenGL. It looks like below. I made simple mosaic effect. The great thing of this is you can program and take result on the screen in real time. We do not need to write GL code directly :) But this tool also has some rules. Because we don't program GL, there are some promised uniform variables. And I'll introduce some important input uniforms. uniform vec3 iResolution    (x,y,z of your screen resolution) uniform float iTime             (current time second info) uniform float iFrame              (current frame number info) uniform vec4 iMouse   ...