TGALoader use DataTextureLoader

[deepkolos]

Description

use DataTexture may use less resource then canvas

[Mugen87]

Interesting idea! Do you mind modifying example/js/loaders/TGALoader.js instead and then generate the module via node utils/modularize.js(executed from the project's root directory).

[Mugen87]

Notice that the texture is now flipped:

https://raw.githack.com/deepkolos/three.js/master/examples/webgl_loader_texture_tga.html
https://threejs.org/examples/webgl_loader_texture_tga

When returning the texture data object in parse(), you have to set flipY to true. You also want to set minFilter to LinearMipmapLinearFilter.

[Mugen87]

To make this work, it's also necessary to enhance DataTextureLoader so you can set generateMipmaps to true in the texture data object. Otherwise mipmaps are not generated.

[deepkolos]

thanks to point out my mistake.

switch back to Loader, and use DataTexture but reset to Texture's default setting

[Mugen87]

I would prefer the usageDataTextureLoader. I maps better to how other loaders work which produce a data texture.

[Mugen87]

Overriding load()in TGALoader should not be necessary if DataTextureLoader is enhanced at one place. But this can be refactored with a later PR.

[deepkolos]

if DataTextureLoader pass texture to the parse function, there is not need to Overriding load()

const texData = scope.parse( buffer, texture );

but not match parse meaning, it missing a step to custom the texture, the current way to do that is returning the setting by parse(), but the setting limited by DataTextureLoader

[Mugen87]

The return object in TGALoader.parse() should look like so:

return {
    data: imageData,
    width: header.width,
    height: header.height,
    flipY: true,
    minFilter: THREE.LinearMipmapLinearFilter,
    generateMipmaps: true
};

DataTextureLoader.parse() needs this enhancement then:

if ( texData.generateMipmaps !== undefined ) {

    texture.generateMipmaps = texData.generateMipmaps;

}

[mrdoob]

Thanks!