Revision control
++ // Copyright (C) 2023 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
++
++ float qt_calcRGBAvg(in vec4 rgba)
++ {
++ return (rgba.r + rgba.g + rgba.b) / 3.0;
++ }
++
++ vec3 qt_defaultMaterialBumpNoLod(in sampler2D inSampler, in float factor,
++ in vec2 texCoord, in vec3 tangent, in vec3 binormal,
++ in vec3 normal)
++ {
++ // invert factor
++ float invFactor = -factor;
++
++ vec2 unitStep = 1.0 / vec2(textureSize(inSampler, 0));
++
++ float du = qt_calcRGBAvg(texture2D(inSampler, vec2(texCoord.x + unitStep.x, texCoord.y)))
++ - qt_calcRGBAvg(texture2D(inSampler, vec2(texCoord.x, texCoord.y)));
++ float dv = qt_calcRGBAvg(texture2D(inSampler, vec2(texCoord.x, texCoord.y + unitStep.y)))
++ - qt_calcRGBAvg(texture2D(inSampler, vec2(texCoord.x, texCoord.y)));
++
++ vec3 n = normalize(vec3(invFactor * du, invFactor * dv, 1.0));
++ n = n.x * normalize(tangent) + n.y * normalize(binormal) + n.z * normal;
++ return normalize(normal + n);
++ }