feat(render): add GLSL shader sources for voxel rendering

render/Shaders.h

@@ -0,0 +1,62 @@
+#pragma once
+
+namespace vf {
+
+inline const char* vertexShaderSource() {
+    return R"(#version 300 es
+precision highp float;
+layout(location = 0) in vec3 aPos;
+layout(location = 1) in vec3 aNormal;
+layout(location = 2) in vec2 aUv;
+layout(location = 3) in float aTile;
+layout(location = 4) in float aLight;
+layout(location = 5) in float aAo;
+uniform mat4 uViewProj;
+out vec3 vNormal;
+out vec2 vUv;
+flat out int vTile;
+out float vDepth;
+out float vLight;
+out float vAo;
+void main() {
+    vec4 clip = uViewProj * vec4(aPos, 1.0);
+    gl_Position = clip;
+    vNormal = aNormal;
+    vUv = aUv;
+    vTile = int(aTile + 0.5);
+    vDepth = clip.w;
+    vLight = aLight;
+    vAo = aAo;
+}
+)";
+}
+
+inline const char* fragmentShaderSource() {
+    return R"(#version 300 es
+precision highp float;
+precision highp sampler2DArray;
+in vec3 vNormal;
+in vec2 vUv;
+flat in int vTile;
+in float vDepth;
+in float vLight;
+in float vAo;
+uniform sampler2DArray uAtlas;
+uniform vec3 uLightDir;
+uniform vec3 uFogColor;
+out vec4 fragColor;
+void main() {
+    vec4 texel = texture(uAtlas, vec3(vUv, float(vTile)));
+    float ndl = max(dot(normalize(vNormal), normalize(uLightDir)), 0.0);
+    float directional = 0.55 + 0.45 * ndl;
+    float baked = 0.18 + 0.82 * vLight;
+    float ao = 0.45 + 0.55 * vAo;
+    vec3 color = texel.rgb * directional * baked * ao;
+    float fog = clamp((vDepth - 90.0) / 90.0, 0.0, 1.0);
+    color = mix(color, uFogColor, fog);
+    fragColor = vec4(color, texel.a);
+}
+)";
+}
+
+} // namespace vf