From f27af1b20ae50de916d35d4fe9bbe1b255582df4 Mon Sep 17 00:00:00 2001 From: ocornut Date: Mon, 20 Jun 2022 16:44:49 +0200 Subject: [PATCH] Internals: SliderBehaviorT: Minor refactor, clearer 0.0/1.0 early out. Should be no-op from user's point of view. ScaleValueFromRatioT() had early 0.0/1.0 ratio tests, shifting most of function by one indent. --- imgui_widgets.cpp | 103 +++++++++++++++++++++------------------------- 1 file changed, 47 insertions(+), 56 deletions(-) diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp index d57e53e6..d552bec4 100644 --- a/imgui_widgets.cpp +++ b/imgui_widgets.cpp @@ -2615,7 +2615,6 @@ float ImGui::ScaleRatioFromValueT(ImGuiDataType data_type, TYPE v, TYPE v_min, T v_max_fudged = -logarithmic_zero_epsilon; float result; - if (v_clamped <= v_min_fudged) result = 0.0f; // Workaround for values that are in-range but below our fudge else if (v_clamped >= v_max_fudged) @@ -2639,91 +2638,81 @@ float ImGui::ScaleRatioFromValueT(ImGuiDataType data_type, TYPE v, TYPE v_min, T return flipped ? (1.0f - result) : result; } - - // Linear slider - return (float)((FLOATTYPE)(SIGNEDTYPE)(v_clamped - v_min) / (FLOATTYPE)(SIGNEDTYPE)(v_max - v_min)); + else + { + // Linear slider + return (float)((FLOATTYPE)(SIGNEDTYPE)(v_clamped - v_min) / (FLOATTYPE)(SIGNEDTYPE)(v_max - v_min)); + } } // Convert a parametric position on a slider into a value v in the output space (the logical opposite of ScaleRatioFromValueT) template TYPE ImGui::ScaleValueFromRatioT(ImGuiDataType data_type, float t, TYPE v_min, TYPE v_max, bool is_logarithmic, float logarithmic_zero_epsilon, float zero_deadzone_halfsize) { - if (v_min == v_max) + // We special-case the extents because otherwise our logarithmic fudging can lead to "mathematically correct" + // but non-intuitive behaviors like a fully-left slider not actually reaching the minimum value. Also generally simpler. + if (t <= 0.0f || v_min == v_max) return v_min; - const bool is_floating_point = (data_type == ImGuiDataType_Float) || (data_type == ImGuiDataType_Double); + if (t >= 1.0f) + return v_max; - TYPE result; + TYPE result = (TYPE)0; if (is_logarithmic) { - // We special-case the extents because otherwise our fudging can lead to "mathematically correct" but non-intuitive behaviors like a fully-left slider not actually reaching the minimum value - if (t <= 0.0f) - result = v_min; - else if (t >= 1.0f) - result = v_max; - else - { - bool flipped = v_max < v_min; // Check if range is "backwards" - - // Fudge min/max to avoid getting silly results close to zero - FLOATTYPE v_min_fudged = (ImAbs((FLOATTYPE)v_min) < logarithmic_zero_epsilon) ? ((v_min < 0.0f) ? -logarithmic_zero_epsilon : logarithmic_zero_epsilon) : (FLOATTYPE)v_min; - FLOATTYPE v_max_fudged = (ImAbs((FLOATTYPE)v_max) < logarithmic_zero_epsilon) ? ((v_max < 0.0f) ? -logarithmic_zero_epsilon : logarithmic_zero_epsilon) : (FLOATTYPE)v_max; + // Fudge min/max to avoid getting silly results close to zero + FLOATTYPE v_min_fudged = (ImAbs((FLOATTYPE)v_min) < logarithmic_zero_epsilon) ? ((v_min < 0.0f) ? -logarithmic_zero_epsilon : logarithmic_zero_epsilon) : (FLOATTYPE)v_min; + FLOATTYPE v_max_fudged = (ImAbs((FLOATTYPE)v_max) < logarithmic_zero_epsilon) ? ((v_max < 0.0f) ? -logarithmic_zero_epsilon : logarithmic_zero_epsilon) : (FLOATTYPE)v_max; - if (flipped) - ImSwap(v_min_fudged, v_max_fudged); + const bool flipped = v_max < v_min; // Check if range is "backwards" + if (flipped) + ImSwap(v_min_fudged, v_max_fudged); - // Awkward special case - we need ranges of the form (-100 .. 0) to convert to (-100 .. -epsilon), not (-100 .. epsilon) - if ((v_max == 0.0f) && (v_min < 0.0f)) - v_max_fudged = -logarithmic_zero_epsilon; + // Awkward special case - we need ranges of the form (-100 .. 0) to convert to (-100 .. -epsilon), not (-100 .. epsilon) + if ((v_max == 0.0f) && (v_min < 0.0f)) + v_max_fudged = -logarithmic_zero_epsilon; - float t_with_flip = flipped ? (1.0f - t) : t; // t, but flipped if necessary to account for us flipping the range + float t_with_flip = flipped ? (1.0f - t) : t; // t, but flipped if necessary to account for us flipping the range - if ((v_min * v_max) < 0.0f) // Range crosses zero, so we have to do this in two parts - { - float zero_point_center = (-(float)ImMin(v_min, v_max)) / ImAbs((float)v_max - (float)v_min); // The zero point in parametric space - float zero_point_snap_L = zero_point_center - zero_deadzone_halfsize; - float zero_point_snap_R = zero_point_center + zero_deadzone_halfsize; - if (t_with_flip >= zero_point_snap_L && t_with_flip <= zero_point_snap_R) - result = (TYPE)0.0f; // Special case to make getting exactly zero possible (the epsilon prevents it otherwise) - else if (t_with_flip < zero_point_center) - result = (TYPE)-(logarithmic_zero_epsilon * ImPow(-v_min_fudged / logarithmic_zero_epsilon, (FLOATTYPE)(1.0f - (t_with_flip / zero_point_snap_L)))); - else - result = (TYPE)(logarithmic_zero_epsilon * ImPow(v_max_fudged / logarithmic_zero_epsilon, (FLOATTYPE)((t_with_flip - zero_point_snap_R) / (1.0f - zero_point_snap_R)))); - } - else if ((v_min < 0.0f) || (v_max < 0.0f)) // Entirely negative slider - result = (TYPE)-(-v_max_fudged * ImPow(-v_min_fudged / -v_max_fudged, (FLOATTYPE)(1.0f - t_with_flip))); + if ((v_min * v_max) < 0.0f) // Range crosses zero, so we have to do this in two parts + { + float zero_point_center = (-(float)ImMin(v_min, v_max)) / ImAbs((float)v_max - (float)v_min); // The zero point in parametric space + float zero_point_snap_L = zero_point_center - zero_deadzone_halfsize; + float zero_point_snap_R = zero_point_center + zero_deadzone_halfsize; + if (t_with_flip >= zero_point_snap_L && t_with_flip <= zero_point_snap_R) + result = (TYPE)0.0f; // Special case to make getting exactly zero possible (the epsilon prevents it otherwise) + else if (t_with_flip < zero_point_center) + result = (TYPE)-(logarithmic_zero_epsilon * ImPow(-v_min_fudged / logarithmic_zero_epsilon, (FLOATTYPE)(1.0f - (t_with_flip / zero_point_snap_L)))); else - result = (TYPE)(v_min_fudged * ImPow(v_max_fudged / v_min_fudged, (FLOATTYPE)t_with_flip)); + result = (TYPE)(logarithmic_zero_epsilon * ImPow(v_max_fudged / logarithmic_zero_epsilon, (FLOATTYPE)((t_with_flip - zero_point_snap_R) / (1.0f - zero_point_snap_R)))); } + else if ((v_min < 0.0f) || (v_max < 0.0f)) // Entirely negative slider + result = (TYPE)-(-v_max_fudged * ImPow(-v_min_fudged / -v_max_fudged, (FLOATTYPE)(1.0f - t_with_flip))); + else + result = (TYPE)(v_min_fudged * ImPow(v_max_fudged / v_min_fudged, (FLOATTYPE)t_with_flip)); } else { // Linear slider + const bool is_floating_point = (data_type == ImGuiDataType_Float) || (data_type == ImGuiDataType_Double); if (is_floating_point) { result = ImLerp(v_min, v_max, t); } - else + else if (t < 1.0) { // - For integer values we want the clicking position to match the grab box so we round above // This code is carefully tuned to work with large values (e.g. high ranges of U64) while preserving this property.. // - Not doing a *1.0 multiply at the end of a range as it tends to be lossy. While absolute aiming at a large s64/u64 // range is going to be imprecise anyway, with this check we at least make the edge values matches expected limits. - if (t < 1.0) - { - FLOATTYPE v_new_off_f = (SIGNEDTYPE)(v_max - v_min) * t; - result = (TYPE)((SIGNEDTYPE)v_min + (SIGNEDTYPE)(v_new_off_f + (FLOATTYPE)(v_min > v_max ? -0.5 : 0.5))); - } - else - { - result = v_max; - } + FLOATTYPE v_new_off_f = (SIGNEDTYPE)(v_max - v_min) * t; + result = (TYPE)((SIGNEDTYPE)v_min + (SIGNEDTYPE)(v_new_off_f + (FLOATTYPE)(v_min > v_max ? -0.5 : 0.5))); } } return result; } -// FIXME: Move more of the code into SliderBehavior() +// FIXME: Try to move more of the code into shared SliderBehavior() template bool ImGui::SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, TYPE* v, const TYPE v_min, const TYPE v_max, const char* format, ImGuiSliderFlags flags, ImRect* out_grab_bb) { @@ -2733,13 +2722,14 @@ bool ImGui::SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType data_typ const ImGuiAxis axis = (flags & ImGuiSliderFlags_Vertical) ? ImGuiAxis_Y : ImGuiAxis_X; const bool is_logarithmic = (flags & ImGuiSliderFlags_Logarithmic) != 0; const bool is_floating_point = (data_type == ImGuiDataType_Float) || (data_type == ImGuiDataType_Double); + const SIGNEDTYPE v_range = (v_min < v_max ? v_max - v_min : v_min - v_max); - const float grab_padding = 2.0f; + // Calculate bounds + const float grab_padding = 2.0f; // FIXME: Should be part of style. const float slider_sz = (bb.Max[axis] - bb.Min[axis]) - grab_padding * 2.0f; float grab_sz = style.GrabMinSize; - SIGNEDTYPE v_range = (v_min < v_max ? v_max - v_min : v_min - v_max); - if (!is_floating_point && v_range >= 0) // v_range < 0 may happen on integer overflows - grab_sz = ImMax((float)(slider_sz / (v_range + 1)), style.GrabMinSize); // For integer sliders: if possible have the grab size represent 1 unit + if (!is_floating_point && v_range >= 0) // v_range < 0 may happen on integer overflows + grab_sz = ImMax((float)(slider_sz / (v_range + 1)), style.GrabMinSize); // For integer sliders: if possible have the grab size represent 1 unit grab_sz = ImMin(grab_sz, slider_sz); const float slider_usable_sz = slider_sz - grab_sz; const float slider_usable_pos_min = bb.Min[axis] + grab_padding + grab_sz * 0.5f; @@ -2770,7 +2760,8 @@ bool ImGui::SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType data_typ else { const float mouse_abs_pos = g.IO.MousePos[axis]; - clicked_t = (slider_usable_sz > 0.0f) ? ImClamp((mouse_abs_pos - slider_usable_pos_min) / slider_usable_sz, 0.0f, 1.0f) : 0.0f; + if (slider_usable_sz > 0.0f) + clicked_t = ImSaturate((mouse_abs_pos - slider_usable_pos_min) / slider_usable_sz); if (axis == ImGuiAxis_Y) clicked_t = 1.0f - clicked_t; set_new_value = true;