bgfx/3rdparty/dear-imgui/widgets/range_slider.inl
Бранимир Караџић 7e0cccc269 Updated ImGui.
2021-10-31 20:07:21 -07:00

223 lines
9.1 KiB
C++

// https://github.com/ocornut/imgui/issues/76
// Taken from: https://github.com/wasikuss/imgui/commit/a50515ace6d9a62ebcd69817f1da927d31c39bb1
namespace ImGui
{
extern float RoundScalarWithFormatFloat(const char* format, ImGuiDataType data_type, float v);
extern float SliderCalcRatioFromValueFloat(ImGuiDataType data_type, float v, float v_min, float v_max, float power, float linear_zero_pos);
// ~80% common code with ImGui::SliderBehavior
bool RangeSliderBehavior(const ImRect& frame_bb, ImGuiID id, float* v1, float* v2, float v_min, float v_max, float power, int decimal_precision, ImGuiSliderFlags flags)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = GetCurrentWindow();
const ImGuiStyle& style = g.Style;
// Draw frame
RenderFrame(frame_bb.Min, frame_bb.Max, GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);
const bool is_non_linear = (power < 1.0f-0.00001f) || (power > 1.0f+0.00001f);
const bool is_horizontal = (flags & ImGuiSliderFlags_Vertical) == 0;
const float grab_padding = 2.0f;
const float slider_sz = is_horizontal ? (frame_bb.GetWidth() - grab_padding * 2.0f) : (frame_bb.GetHeight() - grab_padding * 2.0f);
float grab_sz;
if (decimal_precision > 0)
grab_sz = ImMin(style.GrabMinSize, slider_sz);
else
grab_sz = ImMin(ImMax(1.0f * (slider_sz / ((v_min < v_max ? v_max - v_min : v_min - v_max) + 1.0f)), style.GrabMinSize), slider_sz); // Integer sliders, if possible have the grab size represent 1 unit
const float slider_usable_sz = slider_sz - grab_sz;
const float slider_usable_pos_min = (is_horizontal ? frame_bb.Min.x : frame_bb.Min.y) + grab_padding + grab_sz*0.5f;
const float slider_usable_pos_max = (is_horizontal ? frame_bb.Max.x : frame_bb.Max.y) - grab_padding - grab_sz*0.5f;
// For logarithmic sliders that cross over sign boundary we want the exponential increase to be symmetric around 0.0f
float linear_zero_pos = 0.0f; // 0.0->1.0f
if (v_min * v_max < 0.0f)
{
// Different sign
const float linear_dist_min_to_0 = powf(fabsf(0.0f - v_min), 1.0f/power);
const float linear_dist_max_to_0 = powf(fabsf(v_max - 0.0f), 1.0f/power);
linear_zero_pos = linear_dist_min_to_0 / (linear_dist_min_to_0+linear_dist_max_to_0);
}
else
{
// Same sign
linear_zero_pos = v_min < 0.0f ? 1.0f : 0.0f;
}
// Process clicking on the slider
bool value_changed = false;
if (g.ActiveId == id)
{
if (g.IO.MouseDown[0])
{
const float mouse_abs_pos = is_horizontal ? g.IO.MousePos.x : g.IO.MousePos.y;
float 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 (!is_horizontal)
clicked_t = 1.0f - clicked_t;
float new_value;
if (is_non_linear)
{
// Account for logarithmic scale on both sides of the zero
if (clicked_t < linear_zero_pos)
{
// Negative: rescale to the negative range before powering
float a = 1.0f - (clicked_t / linear_zero_pos);
a = powf(a, power);
new_value = ImLerp(ImMin(v_max,0.0f), v_min, a);
}
else
{
// Positive: rescale to the positive range before powering
float a;
if (fabsf(linear_zero_pos - 1.0f) > 1.e-6f)
a = (clicked_t - linear_zero_pos) / (1.0f - linear_zero_pos);
else
a = clicked_t;
a = powf(a, power);
new_value = ImLerp(ImMax(v_min,0.0f), v_max, a);
}
}
else
{
// Linear slider
new_value = ImLerp(v_min, v_max, clicked_t);
}
char fmt[64];
snprintf(fmt, 64, "%%.%df", decimal_precision);
// Round past decimal precision
new_value = RoundScalarWithFormatFloat(fmt, ImGuiDataType_Float, new_value);
if (*v1 != new_value || *v2 != new_value)
{
if (fabsf(*v1 - new_value) < fabsf(*v2 - new_value))
{
*v1 = new_value;
}
else
{
*v2 = new_value;
}
value_changed = true;
}
}
else
{
ClearActiveID();
}
}
// Calculate slider grab positioning
float grab_t = SliderCalcRatioFromValueFloat(ImGuiDataType_Float, *v1, v_min, v_max, power, linear_zero_pos);
// Draw
if (!is_horizontal)
grab_t = 1.0f - grab_t;
float grab_pos = ImLerp(slider_usable_pos_min, slider_usable_pos_max, grab_t);
ImRect grab_bb1;
if (is_horizontal)
grab_bb1 = ImRect(ImVec2(grab_pos - grab_sz*0.5f, frame_bb.Min.y + grab_padding), ImVec2(grab_pos + grab_sz*0.5f, frame_bb.Max.y - grab_padding));
else
grab_bb1 = ImRect(ImVec2(frame_bb.Min.x + grab_padding, grab_pos - grab_sz*0.5f), ImVec2(frame_bb.Max.x - grab_padding, grab_pos + grab_sz*0.5f));
window->DrawList->AddRectFilled(grab_bb1.Min, grab_bb1.Max, GetColorU32(g.ActiveId == id ? ImGuiCol_SliderGrabActive : ImGuiCol_SliderGrab), style.GrabRounding);
// Calculate slider grab positioning
grab_t = SliderCalcRatioFromValueFloat(ImGuiDataType_Float, *v2, v_min, v_max, power, linear_zero_pos);
// Draw
if (!is_horizontal)
grab_t = 1.0f - grab_t;
grab_pos = ImLerp(slider_usable_pos_min, slider_usable_pos_max, grab_t);
ImRect grab_bb2;
if (is_horizontal)
grab_bb2 = ImRect(ImVec2(grab_pos - grab_sz*0.5f, frame_bb.Min.y + grab_padding), ImVec2(grab_pos + grab_sz*0.5f, frame_bb.Max.y - grab_padding));
else
grab_bb2 = ImRect(ImVec2(frame_bb.Min.x + grab_padding, grab_pos - grab_sz*0.5f), ImVec2(frame_bb.Max.x - grab_padding, grab_pos + grab_sz*0.5f));
window->DrawList->AddRectFilled(grab_bb2.Min, grab_bb2.Max, GetColorU32(g.ActiveId == id ? ImGuiCol_SliderGrabActive : ImGuiCol_SliderGrab), style.GrabRounding);
ImRect connector(grab_bb1.Min, grab_bb2.Max);
connector.Min.x += grab_sz;
connector.Min.y += grab_sz*0.3f;
connector.Max.x -= grab_sz;
connector.Max.y -= grab_sz*0.3f;
window->DrawList->AddRectFilled(connector.Min, connector.Max, GetColorU32(ImGuiCol_SliderGrab), style.GrabRounding);
return value_changed;
}
// ~95% common code with ImGui::SliderFloat
bool RangeSliderFloat(const char* label, float* v1, float* v2, float v_min, float v_max, const char* display_format, float power)
{
ImGuiWindow* window = GetCurrentWindow();
if (window->SkipItems)
return false;
ImGuiContext& g = *GImGui;
const ImGuiStyle& style = g.Style;
const ImGuiID id = window->GetID(label);
const float w = CalcItemWidth();
const ImVec2 label_size = CalcTextSize(label, NULL, true);
const ImRect frame_bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(w, label_size.y + style.FramePadding.y*2.0f));
const ImRect total_bb(frame_bb.Min, frame_bb.Max + ImVec2(label_size.x > 0.0f ? style.ItemInnerSpacing.x + label_size.x : 0.0f, 0.0f));
// NB- we don't call ItemSize() yet because we may turn into a text edit box below
if (!ItemAdd(total_bb, id))
{
ItemSize(total_bb, style.FramePadding.y);
return false;
}
const bool hovered = ItemHoverable(frame_bb, id);
if (hovered)
SetHoveredID(id);
if (!display_format)
display_format = "(%.3f, %.3f)";
int decimal_precision = ImParseFormatPrecision(display_format, 3);
// Tabbing or CTRL-clicking on Slider turns it into an input box
bool start_text_input = false;
const bool tab_focus_requested = (GetItemStatusFlags() & ImGuiItemStatusFlags_FocusedByTabbing) != 0;
if (tab_focus_requested || (hovered && g.IO.MouseClicked[0]))
{
SetActiveID(id, window);
FocusWindow(window);
if (tab_focus_requested || g.IO.KeyCtrl)
{
start_text_input = true;
g.TempInputId = 0;
}
}
if (start_text_input || (g.ActiveId == id && g.TempInputId == id))
{
char fmt[64];
snprintf(fmt, 64, "%%.%df", decimal_precision);
return TempInputScalar(frame_bb, id, label, ImGuiDataType_Float, v1, fmt);
}
ItemSize(total_bb, style.FramePadding.y);
// Actual slider behavior + render grab
const bool value_changed = RangeSliderBehavior(frame_bb, id, v1, v2, v_min, v_max, power, decimal_precision, 0);
// Display value using user-provided display format so user can add prefix/suffix/decorations to the value.
char value_buf[64];
const char* value_buf_end = value_buf + ImFormatString(value_buf, IM_ARRAYSIZE(value_buf), display_format, *v1, *v2);
RenderTextClipped(frame_bb.Min, frame_bb.Max, value_buf, value_buf_end, NULL, ImVec2(0.5f,0.5f));
if (label_size.x > 0.0f)
RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label);
return value_changed;
}
} // namespace ImGui