public final class ShaderEvaluator

Evaluates ShaderNode graphs on the CPU, with the same results the GPU computes from the same graph. Uses:

• Gameplay that follows a shader. A boat that rides the waves a vertex offset draws evaluates the same graph at its own position, so it floats on the water the player sees rather than on an approximation.
• The software renderer, which has no shader compiler.
• Tests of a graph’s values.

import com.codename1.gpu.shader.*;
import com.codename1.gpu.shaders.Water;

ShaderMaterial water = Water.ocean();
float now = 2.5f, boatX = 3f, boatZ = -4f;
ShaderEvaluator ev = new ShaderEvaluator(water)
        .setInput("time", now)
        .setInput("position", boatX, 0f, boatZ);
float lift = ev.evaluate(water.get(ShaderMaterial.Hook.VERTEX_OFFSET))[1];

Inputs are the names of the ShaderNode built ins (position, normal, uv, worldPos, worldNormal, viewDir, cameraPos, sunDir, sunColor, time, baseColor); an input never set reads as zero. Uniforms are read from the material at each evaluation, so a changed value needs nothing else. A graph is compiled to a flat program the first time it is evaluated and kept; evaluating it again allocates nothing except through evaluate(ShaderNode), which returns a new array.

An evaluator is not thread safe.