diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp index 19038da348..93d76f203f 100644 --- a/Marlin/Marlin_main.cpp +++ b/Marlin/Marlin_main.cpp @@ -2590,6 +2590,25 @@ inline void gcode_G0_G1( /** * G2: Clockwise Arc * G3: Counterclockwise Arc + * + * This command has two forms: IJ-form and R-form. + * + * - I specifies an X offset. J specifies a Y offset. + * At least one of the IJ parameters is required. + * X and Y can be omitted to do a complete circle. + * The given XY is not error-checked. The arc ends + * based on the angle of the destination. + * Mixing I or J with R will throw an error. + * + * - R specifies the radius. X or Y is required. + * Omitting both X and Y will throw an error. + * X or Y must differ from the current XY. + * Mixing R with I or J will throw an error. + * + * Examples: + * + * G2 I10 ; CW circle centered at X+10 + * G3 X20 Y12 R14 ; CCW circle with r=14 ending at X20 Y12 */ #if ENABLED(ARC_SUPPORT) inline void gcode_G2_G3(bool clockwise) { @@ -2606,16 +2625,38 @@ inline void gcode_G0_G1( relative_mode = relative_mode_backup; #endif - // Center of arc as offset from current_position - float arc_offset[2] = { - code_seen('I') ? code_value_axis_units(X_AXIS) : 0, - code_seen('J') ? code_value_axis_units(Y_AXIS) : 0 - }; + float arc_offset[2] = { 0.0, 0.0 }; + if (code_seen('R')) { + const float r = code_value_axis_units(X_AXIS), + x1 = current_position[X_AXIS], y1 = current_position[Y_AXIS], + x2 = destination[X_AXIS], y2 = destination[Y_AXIS]; + if (r && (x2 != x1 || y2 != y1)) { + const float e = clockwise ? -1 : 1, // clockwise -1, counterclockwise 1 + dx = x2 - x1, dy = y2 - y1, // X and Y differences + d = HYPOT(dx, dy), // Linear distance between the points + h = sqrt(sq(r) - sq(d * 0.5)), // Distance to the arc pivot-point + mx = (x1 + x2) * 0.5, my = (y1 + y2) * 0.5, // Point between the two points + sx = -dy / d, sy = dx / d, // Slope of the perpendicular bisector + cx = mx + e * h * sx, cy = my + e * h * sy; // Pivot-point of the arc + arc_offset[X_AXIS] = cx - x1; + arc_offset[Y_AXIS] = cy - y1; + } + } + else { + if (code_seen('I')) arc_offset[X_AXIS] = code_value_axis_units(X_AXIS); + if (code_seen('J')) arc_offset[Y_AXIS] = code_value_axis_units(Y_AXIS); + } - // Send an arc to the planner - plan_arc(destination, arc_offset, clockwise); - - refresh_cmd_timeout(); + if (arc_offset[0] || arc_offset[1]) { + // Send an arc to the planner + plan_arc(destination, arc_offset, clockwise); + refresh_cmd_timeout(); + } + else { + // Bad arguments + SERIAL_ERROR_START; + SERIAL_ERRORLNPGM(MSG_ERR_ARC_ARGS); + } } } #endif diff --git a/Marlin/language.h b/Marlin/language.h index 6311e6c600..5dbcc0ddea 100644 --- a/Marlin/language.h +++ b/Marlin/language.h @@ -150,6 +150,7 @@ #define MSG_ERR_MATERIAL_INDEX "M145 S out of range (0-1)" #define MSG_ERR_M421_PARAMETERS "M421 requires XYZ or IJZ parameters" #define MSG_ERR_MESH_XY "Mesh XY or IJ cannot be resolved" +#define MSG_ERR_ARC_ARGS "G2/G3 bad parameters" #define MSG_ERR_M428_TOO_FAR "Too far from reference point" #define MSG_ERR_M303_DISABLED "PIDTEMP disabled" #define MSG_M119_REPORT "Reporting endstop status"