// GraphicsUniforms — the shared per-frame UBO (binding 0). single source, spliced into shaders
// by the crGraphics include preprocessor. the CPU mirror lives in crGraphicsUniforms.h
// and must match this layout.
// explicit highp — block member precisions must match across stages (WebGL2 enforces this)
layout(std140) uniform GraphicsUniforms {
    highp mat4 u_viewProjection;
    highp mat4 u_lightVP[3];      // frustum-fitted shadow cascades, near to far
    highp vec3 u_cameraPos;
    highp vec3 u_lightDir;
    highp vec4 u_lightColor;      // rgb = color (linear, pre-converted on upload), a = intensity
    highp vec4 u_ambientSky;      // rgb = color (linear), a = strength — hemisphere, +Y normals
    highp vec4 u_ambientGround;   // rgb = color (linear), a = strength — hemisphere, -Y normals
    highp vec4 u_specParams;      // x = shininess, y = strength
    highp vec4 u_shadowParams;    // x = bias (world meters), y = strength, z = normal offset (shadow texels), w = darkness
    highp vec4 u_shadowCascadeParams[3];   // per cascade, precomputed on upload: x = texel world size, y = bias (depth01), zw = texel uv size
    highp vec4 u_fogColor;        // rgb = color (linear, pre-converted on upload), a = enabled (0/1)
    highp vec4 u_fogParams;       // x = start, y = end (view-space meters)
    highp vec4 u_timeParams;      // x = sim time (pauses with the sim), y = real time (always flows) — seconds, both wrap at 600
};