Make PathArcTo accept counter-clockwise angles (#4030, #3491)
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 104ccca..a1a4d7ef6 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -54,6 +54,7 @@
- LabelText: Fixed clipping of multi-line value text when label is single-line. (#4004)
- LabelText: Fixed vertical alignment of single-line value text when label is multi-line. (#4004)
- Popups: Added 'OpenPopup(ImGuiID id)' overload to facilitate calling from nested stacks. (#3993, #331) [@zlash]
+- ImDrawList: Fixed PathArcTo() regression from 1.82 preventing use of counter-clockwise angles. (#4030, #3491) [@thedmd]
- Demo: Improved popups demo and comments.
- Backends: SDL: Rework global mouse pos availability check listing supported platforms explicitly,
effectively fixing mouse access on Raspberry Pi. (#2837, #3950) [@lethal-guitar, @hinxx]
diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index 6c0d10a..2b0fdb8 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -1037,7 +1037,6 @@
_Path.push_back(center);
return;
}
- IM_ASSERT(a_min_sample <= a_max_sample);
// Calculate arc auto segment step size
if (a_step <= 0)
@@ -1046,17 +1045,7 @@
// Make sure we never do steps larger than one quarter of the circle
a_step = ImClamp(a_step, 1, IM_DRAWLIST_ARCFAST_TABLE_SIZE / 4);
- // Normalize a_min_sample to always start lie in [0..IM_DRAWLIST_ARCFAST_SAMPLE_MAX] range.
- if (a_min_sample < 0)
- {
- int normalized_sample = a_min_sample % IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
- if (normalized_sample < 0)
- normalized_sample += IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
- a_max_sample += (normalized_sample - a_min_sample);
- a_min_sample = normalized_sample;
- }
-
- const int sample_range = a_max_sample - a_min_sample;
+ const int sample_range = ImAbs(a_max_sample - a_min_sample);
const int a_next_step = a_step;
int samples = sample_range + 1;
@@ -1082,16 +1071,40 @@
ImVec2* out_ptr = _Path.Data + (_Path.Size - samples);
int sample_index = a_min_sample;
- for (int a = a_min_sample; a <= a_max_sample; a += a_step, sample_index += a_step, a_step = a_next_step)
+ if (sample_index < 0 || sample_index >= IM_DRAWLIST_ARCFAST_SAMPLE_MAX)
{
- // a_step is clamped to IM_DRAWLIST_ARCFAST_SAMPLE_MAX, so we have guaranteed that it will not wrap over range twice or more
- if (sample_index >= IM_DRAWLIST_ARCFAST_SAMPLE_MAX)
- sample_index -= IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
+ sample_index = sample_index % IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
+ if (sample_index < 0)
+ sample_index += IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
+ }
- const ImVec2 s = _Data->ArcFastVtx[sample_index];
- out_ptr->x = center.x + s.x * radius;
- out_ptr->y = center.y + s.y * radius;
- out_ptr++;
+ if (a_max_sample >= a_min_sample)
+ {
+ for (int a = a_min_sample; a <= a_max_sample; a += a_step, sample_index += a_step, a_step = a_next_step)
+ {
+ // a_step is clamped to IM_DRAWLIST_ARCFAST_SAMPLE_MAX, so we have guaranteed that it will not wrap over range twice or more
+ if (sample_index >= IM_DRAWLIST_ARCFAST_SAMPLE_MAX)
+ sample_index -= IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
+
+ const ImVec2 s = _Data->ArcFastVtx[sample_index];
+ out_ptr->x = center.x + s.x * radius;
+ out_ptr->y = center.y + s.y * radius;
+ out_ptr++;
+ }
+ }
+ else
+ {
+ for (int a = a_min_sample; a >= a_max_sample; a -= a_step, sample_index -= a_step, a_step = a_next_step)
+ {
+ // a_step is clamped to IM_DRAWLIST_ARCFAST_SAMPLE_MAX, so we have guaranteed that it will not wrap over range twice or more
+ if (sample_index < 0)
+ sample_index += IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
+
+ const ImVec2 s = _Data->ArcFastVtx[sample_index];
+ out_ptr->x = center.x + s.x * radius;
+ out_ptr->y = center.y + s.y * radius;
+ out_ptr++;
+ }
}
if (extra_max_sample)
@@ -1116,7 +1129,6 @@
_Path.push_back(center);
return;
}
- IM_ASSERT(a_min <= a_max);
// Note that we are adding a point at both a_min and a_max.
// If you are trying to draw a full closed circle you don't want the overlapping points!
@@ -1136,7 +1148,6 @@
_Path.push_back(center);
return;
}
- IM_ASSERT(a_min_of_12 <= a_max_of_12);
_PathArcToFastEx(center, radius, a_min_of_12 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, a_max_of_12 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 0);
}
@@ -1147,7 +1158,6 @@
_Path.push_back(center);
return;
}
- IM_ASSERT(a_min <= a_max);
if (num_segments > 0)
{
@@ -1158,28 +1168,33 @@
// Automatic segment count
if (radius <= _Data->ArcFastRadiusCutoff)
{
+ const bool a_is_reverse = a_max < a_min;
+
// We are going to use precomputed values for mid samples.
// Determine first and last sample in lookup table that belong to the arc.
- const int a_min_sample = (int)ImCeil(IM_DRAWLIST_ARCFAST_SAMPLE_MAX * a_min / (IM_PI * 2.0f));
- const int a_max_sample = (int)( IM_DRAWLIST_ARCFAST_SAMPLE_MAX * a_max / (IM_PI * 2.0f));
- const int a_mid_samples = ImMax(a_max_sample - a_min_sample, 0);
+ const float a_min_sample_f = IM_DRAWLIST_ARCFAST_SAMPLE_MAX * a_min / (IM_PI * 2.0f);
+ const float a_max_sample_f = IM_DRAWLIST_ARCFAST_SAMPLE_MAX * a_max / (IM_PI * 2.0f);
+
+ const int a_min_sample = a_is_reverse ? (int)ImFloorSigned(a_min_sample_f) : (int)ImCeil(a_min_sample_f);
+ const int a_max_sample = a_is_reverse ? (int)ImCeil(a_max_sample_f) : (int)ImFloorSigned(a_max_sample_f);
+ const int a_mid_samples = a_is_reverse ? ImMax(a_min_sample - a_max_sample, 0) : ImMax(a_max_sample - a_min_sample, 0);
const float a_min_segment_angle = a_min_sample * IM_PI * 2.0f / IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
const float a_max_segment_angle = a_max_sample * IM_PI * 2.0f / IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
- const bool a_emit_start = (a_min_segment_angle - a_min) > 0.0f;
- const bool a_emit_end = (a_max - a_max_segment_angle) > 0.0f;
+ const bool a_emit_start = (a_min_segment_angle - a_min) != 0.0f;
+ const bool a_emit_end = (a_max - a_max_segment_angle) != 0.0f;
_Path.reserve(_Path.Size + (a_mid_samples + 1 + (a_emit_start ? 1 : 0) + (a_emit_end ? 1 : 0)));
if (a_emit_start)
_Path.push_back(ImVec2(center.x + ImCos(a_min) * radius, center.y + ImSin(a_min) * radius));
- if (a_max_sample >= a_min_sample)
+ if (a_mid_samples > 0)
_PathArcToFastEx(center, radius, a_min_sample, a_max_sample, 0);
if (a_emit_end)
_Path.push_back(ImVec2(center.x + ImCos(a_max) * radius, center.y + ImSin(a_max) * radius));
}
else
{
- const float arc_length = a_max - a_min;
+ const float arc_length = ImAbs(a_max - a_min);
const int circle_segment_count = _CalcCircleAutoSegmentCount(radius);
const int arc_segment_count = ImMax((int)ImCeil(circle_segment_count * arc_length / (IM_PI * 2.0f)), (int)(2.0f * IM_PI / arc_length));
_PathArcToN(center, radius, a_min, a_max, arc_segment_count);
diff --git a/imgui_internal.h b/imgui_internal.h
index cb8924a..c100cfc 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -371,6 +371,7 @@
static inline double ImPow(double x, double y) { return pow(x, y); }
static inline float ImLog(float x) { return logf(x); } // DragBehaviorT/SliderBehaviorT uses ImLog with either float/double and need the precision
static inline double ImLog(double x) { return log(x); }
+static inline int ImAbs(int x) { return x < 0 ? -x : x; }
static inline float ImAbs(float x) { return fabsf(x); }
static inline double ImAbs(double x) { return fabs(x); }
static inline float ImSign(float x) { return (x < 0.0f) ? -1.0f : ((x > 0.0f) ? 1.0f : 0.0f); } // Sign operator - returns -1, 0 or 1 based on sign of argument
