Fix part of #35372: distorted strokes when painting zoomed out with a small brush

size. Interpolated mouse coordinates should not get rounded to integers.

4 files changed, 12 insertions, 20 deletions

diff --git a/source/blender/editors/sculpt_paint/paint_image.c b/source/blender/editors/sculpt_paint/paint_image.c
index 92b82d84c38..6547b336119 100644
--- a/source/blender/editors/sculpt_paint/paint_image.c
+++ b/source/blender/editors/sculpt_paint/paint_image.c
@@ -446,7 +446,7 @@ typedef struct PaintOperation {
 
 	void *custom_paint;
 
-	int prevmouse[2];
+	float prevmouse[2];
 	double starttime;
 
 	ViewContext vc;
@@ -545,13 +545,11 @@ static void paint_stroke_update_step(bContext *C, struct PaintStroke *stroke, Po
 	float startsize = BKE_brush_size_get(scene, brush);
 	float startalpha = BKE_brush_alpha_get(scene, brush);
 
-	float mousef[2];
+	float mouse[2];
 	float pressure;
-	int mouse[2], redraw, eraser;
+	int redraw, eraser;
 
-	RNA_float_get_array(itemptr, "mouse", mousef);
-	mouse[0] = (int)(mousef[0]);
-	mouse[1] = (int)(mousef[1]);
+	RNA_float_get_array(itemptr, "mouse", mouse);
 	pressure = RNA_float_get(itemptr, "pressure");
 	eraser = RNA_boolean_get(itemptr, "pen_flip");
 
diff --git a/source/blender/editors/sculpt_paint/paint_image_2d.c b/source/blender/editors/sculpt_paint/paint_image_2d.c
index 48a23641bdb..956dcc858f8 100644
--- a/source/blender/editors/sculpt_paint/paint_image_2d.c
+++ b/source/blender/editors/sculpt_paint/paint_image_2d.c
@@ -1016,7 +1016,7 @@ static void paint_2d_canvas_free(ImagePaintState *s)
 		image_undo_remove_masks();
 }
 
-int paint_2d_stroke(void *ps, const int prev_mval[2], const int mval[2], int eraser)
+int paint_2d_stroke(void *ps, const float prev_mval[2], const float mval[2], int eraser)
 {
 	float newuv[2], olduv[2];
 	int redraw = 0;
diff --git a/source/blender/editors/sculpt_paint/paint_image_proj.c b/source/blender/editors/sculpt_paint/paint_image_proj.c
index 0aef1ccf9fe..d7cea395409 100644
--- a/source/blender/editors/sculpt_paint/paint_image_proj.c
+++ b/source/blender/editors/sculpt_paint/paint_image_proj.c
@@ -3206,7 +3206,7 @@ static void project_paint_begin(ProjPaintState *ps)
 	BLI_linklist_free(image_LinkList, NULL);
 }
 
-static void paint_proj_begin_clone(ProjPaintState *ps, const int mouse[2])
+static void paint_proj_begin_clone(ProjPaintState *ps, const float mouse[2])
 {
 	/* setup clone offset */
 	if (ps->tool == PAINT_TOOL_CLONE) {
@@ -4044,23 +4044,17 @@ static int project_paint_op(void *state, const float lastpos[2], const float pos
 }
 
 
-int paint_proj_stroke(bContext *C, void *pps, const int prevmval_i[2], const int mval_i[2])
+int paint_proj_stroke(bContext *C, void *pps, const float prev_pos[2], const float pos[2])
 {
 	ProjPaintState *ps = pps;
 	int a, redraw;
-	float pos[2], prev_pos[2];
-
-	pos[0] = (float)(mval_i[0]);
-	pos[1] = (float)(mval_i[1]);
-
-	prev_pos[0] = (float)(prevmval_i[0]);
-	prev_pos[1] = (float)(prevmval_i[1]);
 
 	/* clone gets special treatment here to avoid going through image initialization */
 	if (ps->tool == PAINT_TOOL_CLONE && ps->mode == BRUSH_STROKE_INVERT) {
 		Scene *scene = ps->scene;
 		View3D *v3d = ps->v3d;
 		float *cursor = give_cursor(scene, v3d);
+		int mval_i[2] = {(int)pos[0], (int)pos[1]};
 
 		view3d_operator_needs_opengl(C);
 
@@ -4160,7 +4154,7 @@ static void project_state_init(bContext *C, Object *ob, ProjPaintState *ps, int
 	return;
 }
 
-void *paint_proj_new_stroke(bContext *C, Object *ob, const int mouse[2], int mode)
+void *paint_proj_new_stroke(bContext *C, Object *ob, const float mouse[2], int mode)
 {
 	ProjPaintState *ps = MEM_callocN(sizeof(ProjPaintState), "ProjectionPaintState");
 	project_state_init(C, ob, ps, mode);
diff --git a/source/blender/editors/sculpt_paint/paint_intern.h b/source/blender/editors/sculpt_paint/paint_intern.h
index 0085998bd58..a4230439737 100644
--- a/source/blender/editors/sculpt_paint/paint_intern.h
+++ b/source/blender/editors/sculpt_paint/paint_intern.h
@@ -141,9 +141,9 @@ int get_imapaint_zoom(struct bContext *C, float *zoomx, float *zoomy);
 void *paint_2d_new_stroke(struct bContext *, struct wmOperator *);
 void paint_2d_redraw(const bContext *C, void *ps, int final);
 void paint_2d_stroke_done(void *ps);
-int paint_2d_stroke(void *ps, const int prev_mval[2], const int mval[2], int eraser);
-void *paint_proj_new_stroke(struct bContext *C, struct Object *ob, const int mouse[2], int mode);
-int paint_proj_stroke(struct bContext *C, void *ps, const int prevmval_i[2], const int mval_i[2]);
+int paint_2d_stroke(void *ps, const float prev_mval[2], const float mval[2], int eraser);
+void *paint_proj_new_stroke(struct bContext *C, struct Object *ob, const float mouse[2], int mode);
+int paint_proj_stroke(struct bContext *C, void *ps, const float prevmval_i[2], const float mval_i[2]);
 void paint_proj_stroke_done(void *ps);
 void paint_brush_init_tex(struct Brush *brush);
 void paint_brush_exit_tex(struct Brush *brush);