In working on the port of the h & v big Blur, I have found interesting behavior with the effect uniform pixelSize. I am wondering about the best way to handle this.
The first effect and second effect have different 'relative' pixelSize, so it's not possible to use the same value multiplied by pixelSize to blur each. The first effect renders to offscreen FB from source texture from spritesheet, the second effect renders to Canvas FB from the offscreen FB. It seems like due to differences between the two, the pixelSize is relatively different (e.g. between spritesheet texture and offscreen FB texture.) What's the best method to make these similar?
I am going to experiment with using must-predraw to see if it would make the behavior consistent (then both will render to offscreen FB first and use that texture.)
Here's an example of the uniforms from one frame of render (captured by Spector.js):
Another interesting thing for me was how srcOriginEnd and srcOriginStart can be flipped in terms of which one is higher (at least for the Y value), so I cannot just use clamp (vTex, srcOriginStart, srcOriginEnd) to clamp to vTex to the texture bounds, I had to create a 'new' clamp function which uses min and max of the two.
mediump vec2 newTex = vTex + vec2(halfPixelHeight, pos * realSizeH);
newTex.x = clamp(newTex.x,min(srcOriginStart.x, srcOriginEnd.x),max(srcOriginStart.x, srcOriginEnd.x));
newTex.y = clamp(newTex.y,min(srcOriginStart.y, srcOriginEnd.y),max(srcOriginStart.y, srcOriginEnd.y));
Here's the example plugins:
Note the example project has opacity set to 99% to add yet another effect to the stack and make the behavior consistent. Set the opacity to 100% to see similar results as above.