Fix SliderFloat resetting small values (below 0.001) to zero

[Copilot]

applyFormatToValue converts printf format strings (e.g., "%.4f") into pre-formatted literal strings (e.g., "0.0001"), stripping the % specifier. This causes two problems in ImGui:

1. Broken precision parsing: ImParseFormatPrecision falls back to default precision 3 when it finds no %, setting logarithmic_zero_epsilon = 0.001. On logarithmic sliders with min=0, any value ≤ 0.001 gets a ratio of 0 and snaps to v_min (0) on interaction.
2. Rounding to zero: RoundScalarWithFormatT rounds slider values to the format's precision during interaction. With "%.3f", any value below 0.001 rounds to 0.

Fix

Two changes in BasicSlider:

1. Pass original printf format to ImGui: When tryMaintainFormat=true for floats, return the original format string (e.g., "%.4f") instead of a pre-formatted literal. This matches the existing behavior for int types and allows ImGui to correctly parse the precision for logarithmic epsilon calculation.

2. Add ImGuiSliderFlags_NoRoundToFormat: Prevents RoundScalarWithFormatT from rounding small values to zero during slider interaction. This flag is explicitly recommended by ImGui's documentation for logarithmic sliders with limited-precision format strings.

// applyFormatToValue: return original format for floats when tryMaintainFormat=true
if constexpr (std::is_same_v<T, float>) {
    if (tryMaintainFormat) {
        return format;  // e.g., "%.4f" instead of "0.0001"
    }
    // ... existing pre-formatting for display strings ...
}

// BasicSlider: add NoRoundToFormat flag for float sliders
auto flags = ImGuiSliderFlags_NoRoundToFormat | (parameters._logarithmic ? ImGuiSliderFlags_Logarithmic : 0);
result |= ImGui::SliderFloat("##slider", &sliderValue, parameters._min, parameters._max, format.c_str(), flags);

• Pre-formatted display strings (with comma separators) are still used for the tryMaintainFormat=false path (e.g., collapsed color-dependent range display)
• Int sliders are unchanged

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[chrxh]

@copilot that is not the reason. still the same problem

[Copilot]

@copilot that is not the reason. still the same problem

You're right, the format string change wasn't the root cause. The actual issue is twofold:

1. applyFormatToValue converts printf formats like "%.4f" into pre-formatted strings like "0.0001", stripping the % specifier. This causes ImGui's ImParseFormatPrecision to fall back to default precision 3, setting logarithmic_zero_epsilon=0.001 — so any value ≤ 0.001 gets snapped to 0 on logarithmic sliders.

2. RoundScalarWithFormatT rounds values below the format precision to 0 during slider interaction.

New fix in 2cec2ea:

• Return original printf format when tryMaintainFormat=true for floats (matching existing int behavior), so ImGui can correctly parse the precision
• Add ImGuiSliderFlags_NoRoundToFormat to prevent rounding (as ImGui docs recommend for logarithmic sliders)