Fix T61791: Motion path step is not taken into account

1 files changed, 37 insertions, 44 deletions

diff --git a/source/blender/draw/intern/draw_anim_viz.c b/source/blender/draw/intern/draw_anim_viz.c
index 2c2f1a7f0fd..2689d2726d8 100644
--- a/source/blender/draw/intern/draw_anim_viz.c
+++ b/source/blender/draw/intern/draw_anim_viz.c
@@ -142,6 +142,33 @@ static void MPATH_cache_init(void *vedata)
 	}
 }
 
+static void MPATH_get_frame_range_to_draw(
+        bAnimVizSettings *avs, bMotionPath *mpath, int current_frame,
+        int *r_start, int *r_end, int *r_step)
+{
+	int start, end;
+
+	if (avs->path_type == MOTIONPATH_TYPE_ACFRA) {
+		start = current_frame - avs->path_bc;
+		end = current_frame + avs->path_ac + 1;
+	}
+	else {
+		start = avs->path_sf;
+		end = avs->path_ef;
+	}
+
+	if (start > end) {
+		SWAP(int, start, end);
+	}
+
+	CLAMP(start, mpath->start_frame, mpath->end_frame);
+	CLAMP(end, mpath->start_frame, mpath->end_frame);
+
+	*r_start = start;
+	*r_end = end;
+	*r_step = max_ii(avs->path_step, 1);
+}
+
 static void MPATH_cache_motion_path(MPATH_PassList *psl,
                                     Object *ob, bPoseChannel *pchan,
                                     bAnimVizSettings *avs, bMotionPath *mpath)
@@ -149,53 +176,18 @@ static void MPATH_cache_motion_path(MPATH_PassList *psl,
 	const DRWContextState *draw_ctx = DRW_context_state_get();
 	struct DRWTextStore *dt = DRW_text_cache_ensure();
 	int txt_flag = DRW_TEXT_CACHE_GLOBALSPACE | DRW_TEXT_CACHE_ASCII;
-	int stepsize = avs->path_step;
-	int sfra, efra, sind, len;
 	int cfra = (int)DEG_get_ctime(draw_ctx->depsgraph);
 	bool sel = (pchan) ? (pchan->bone->flag & BONE_SELECTED) : (ob->flag & SELECT);
 	bool show_keyframes = (avs->path_viewflag & MOTIONPATH_VIEW_KFRAS) != 0;
-	bMotionPathVert *mpv, *mpv_start;
 
-	/* get frame ranges */
-	if (avs->path_type == MOTIONPATH_TYPE_ACFRA) {
-		/* With "Around Current", we only choose frames from around
-		 * the current frame to draw.
-		 */
-		sfra = cfra - avs->path_bc;
-		efra = cfra + avs->path_ac + 1;
-	}
-	else {
-		/* Use the current display range */
-		sfra = avs->path_sf;
-		efra = avs->path_ef;
-	}
-
-	/* no matter what, we can only show what is in the cache and no more
-	 * - abort if whole range is past ends of path
-	 * - otherwise clamp endpoints to extents of path
-	 */
-	if (sfra < mpath->start_frame) {
-		/* start clamp */
-		sfra = mpath->start_frame;
-	}
-	if (efra > mpath->end_frame) {
-		/* end clamp */
-		efra = mpath->end_frame;
-	}
-
-	if ((sfra > mpath->end_frame) || (efra < mpath->start_frame)) {
-		/* whole path is out of bounds */
-		return;
-	}
-
-	len = efra - sfra;
+	int sfra, efra, stepsize;
+	MPATH_get_frame_range_to_draw(avs, mpath, cfra, &sfra, &efra, &stepsize);
 
-	if ((len <= 0) || (mpath->points == NULL)) {
+	int len = efra - sfra;
+	if (len == 0) {
 		return;
 	}
-
-	sind = sfra - mpath->start_frame;
-	mpv_start = (mpath->points + sind);
+	int start_index = sfra - mpath->start_frame;
 
 	bool use_custom_col = (mpath->flag & MOTIONPATH_FLAG_CUSTOM) != 0;
 
@@ -216,16 +208,15 @@ static void MPATH_cache_motion_path(MPATH_PassList *psl,
 			DRW_shgroup_uniform_vec3(shgrp, "customColor", mpath->color, 1);
 		}
 		/* Only draw the required range. */
-		DRW_shgroup_call_range_add(shgrp, mpath_batch_line_get(mpath), NULL, sind, len);
+		DRW_shgroup_call_range_add(shgrp, mpath_batch_line_get(mpath), NULL, start_index, len);
 	}
 
 	/* Draw points. */
 	DRWShadingGroup *shgrp = DRW_shgroup_create(mpath_points_shader_get(), psl->points);
 	DRW_shgroup_uniform_int_copy(shgrp, "frameCurrent", cfra);
 	DRW_shgroup_uniform_int_copy(shgrp, "cacheStart", mpath->start_frame);
-	DRW_shgroup_uniform_int_copy(shgrp, "pointSize", mpath->line_thickness);
+	DRW_shgroup_uniform_int_copy(shgrp, "pointSize", max_ii(mpath->line_thickness - 1, 1));
 	DRW_shgroup_uniform_int_copy(shgrp, "stepSize", stepsize);
-	DRW_shgroup_uniform_bool_copy(shgrp, "selected", sel);
 	DRW_shgroup_uniform_bool_copy(shgrp, "showKeyFrames", show_keyframes);
 	DRW_shgroup_uniform_bool_copy(shgrp, "useCustomColor", use_custom_col);
 	DRW_shgroup_uniform_block(shgrp, "globalsBlock", G_draw.block_ubo);
@@ -233,7 +224,7 @@ static void MPATH_cache_motion_path(MPATH_PassList *psl,
 		DRW_shgroup_uniform_vec3(shgrp, "customColor", mpath->color, 1);
 	}
 	/* Only draw the required range. */
-	DRW_shgroup_call_range_add(shgrp, mpath_batch_points_get(mpath), NULL, sind, len);
+	DRW_shgroup_call_range_add(shgrp, mpath_batch_points_get(mpath), NULL, start_index, len);
 
 	/* Draw frame numbers at each framestep value */
 	bool show_kf_no = (avs->path_viewflag & MOTIONPATH_VIEW_KFNOS) != 0;
@@ -244,6 +235,8 @@ static void MPATH_cache_motion_path(MPATH_PassList *psl,
 		UI_GetThemeColor3ubv(TH_VERTEX_SELECT, col_kf);
 		col[3] = col_kf[3] = 255;
 
+		bMotionPathVert *mpv;
+		bMotionPathVert *mpv_start = mpath->points + start_index;
 		for (i = 0, mpv = mpv_start; i < len; i += stepsize, mpv += stepsize) {
 			int frame = sfra + i;
 			char numstr[32];