Prepare for per-channel param adjustment

5 files changed, 215 insertions, 359 deletions

diff --git a/Makefile b/Makefile
index cb49812..02ee360 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,7 @@ INC_FLAGS   := $(addprefix -I,$(INC_DIRS))
 INC_FLAGS   += -I$(LIBGBA_SRC)
 
 # Output library names and executables.
-TARGET         := STEPPER-v1.2
+TARGET         := STEPPER-v1.3-dev
 ELF            := $(BUILD_DIR)/$(TARGET).elf
 BIN            := $(BUILD_DIR)/$(TARGET).gba
 
diff --git a/src/drawing.c b/src/drawing.c
index 964c4ce..0ee1243 100644
--- a/src/drawing.c
+++ b/src/drawing.c
@@ -14,18 +14,10 @@ draw_channels(void) {
     for (size_t i = 0; i < 4; i++) {
         bool active = false;
         switch (i) {
-            case 0: {
-                active = patterns[pattern_selection_loc].ch1.active;
-            } break;
-            case 1: {
-                active = patterns[pattern_selection_loc].ch2.active;
-            } break;
-            case 2: {
-                active = patterns[pattern_selection_loc].ch3.active;
-            } break;
-            case 3: {
-                active = patterns[pattern_selection_loc].ch4.active;
-            } break;
+            case 0: { active = patterns[pattern_selection_loc].ch1.active; } break;
+            case 1: { active = patterns[pattern_selection_loc].ch2.active; } break;
+            case 2: { active = patterns[pattern_selection_loc].ch3.active; } break;
+            case 3: { active = patterns[pattern_selection_loc].ch4.active; } break;
         }
         u8 clr = active ? COL_FG : COL_GREY;
         size_t y = CHAN_START_Y + i * CHAN_OFFSET_Y;
@@ -62,18 +54,10 @@ void
 draw_trigger(size_t chan, size_t i) {
     TriggerNote trig = {0};
     switch (chan) {
-        case 0: {
-            trig = patterns[pattern_selection_loc].ch1.notes[i];
-        } break;
-        case 1: {
-            trig = patterns[pattern_selection_loc].ch2.notes[i];
-        } break;
-        case 2: {
-            trig = patterns[pattern_selection_loc].ch3.notes[i];
-        } break;
-        case 3: {
-            trig = patterns[pattern_selection_loc].ch4.notes[i];
-        } break;
+        case 0: { trig = patterns[pattern_selection_loc].ch1.notes[i]; } break;
+        case 1: { trig = patterns[pattern_selection_loc].ch2.notes[i]; } break;
+        case 2: { trig = patterns[pattern_selection_loc].ch3.notes[i]; } break;
+        case 3: { trig = patterns[pattern_selection_loc].ch4.notes[i]; } break;
     }
     if (trig.active) {
         size_t offset_x = TRIG_OFFSET_X * (i % 8);
@@ -373,21 +357,11 @@ draw_note(u8 note, u8 clr) {
             y0 = PIANO_START_Y + 2;
             y1 = PIANO_START_Y - 2 + 11;
             switch (value) {
-                case 1: {
-                    x0 = PIANO_START_X + 2 + octave * 28 + 3;
-                } break;
-                case 3: {
-                    x0 = PIANO_START_X + 2 + octave * 28 + 7;
-                } break;
-                case 6: {
-                    x0 = PIANO_START_X + 2 + octave * 28 + 15;
-                } break;
-                case 8: {
-                    x0 = PIANO_START_X + 2 + octave * 28 + 19;
-                } break;
-                case 10: {
-                    x0 = PIANO_START_X + 2 + octave * 28 + 23;
-                } break;
+                case 1: { x0 = PIANO_START_X + 2 + octave * 28 + 3; } break;
+                case 3: { x0 = PIANO_START_X + 2 + octave * 28 + 7; } break;
+                case 6: { x0 = PIANO_START_X + 2 + octave * 28 + 15; } break;
+                case 8: { x0 = PIANO_START_X + 2 + octave * 28 + 19; } break;
+                case 10: { x0 = PIANO_START_X + 2 + octave * 28 + 23; } break;
             }
             x1 = x0;
             draw_line(x0, y0, x1, y1, clr);
@@ -512,18 +486,10 @@ draw_params_cursor_square(size_t i, u8 clr, bool sweep) {
 void
 draw_params_cursor(size_t i, u8 clr) {
     switch (channel_selection_loc) {
-        case 0: {
-            draw_params_cursor_square(i, clr, true);
-        } break;
-        case 1: {
-            draw_params_cursor_square(i, clr, false);
-        } break;
-        case 2: {
-            draw_params_cursor_wave(i, clr);
-        } break;
-        case 3: {
-            draw_params_cursor_noise(i, clr);
-        } break;
+        case 0: { draw_params_cursor_square(i, clr, true); } break;
+        case 1: { draw_params_cursor_square(i, clr, false); } break;
+        case 2: { draw_params_cursor_wave(i, clr); } break;
+        case 3: { draw_params_cursor_noise(i, clr); } break;
     }
 }
 
@@ -555,12 +521,11 @@ clear_parameters(void) {
 
 IWRAM_CODE
 void
-draw_parameters_wave(void) {
+draw_parameters_wave(ChannelWaveParams *params) {
     // Draw current wave data.
-    Pattern *pat = &patterns[pattern_selection_loc];
     {
-        u8 *wave_a = pat->ch3.params[trig_selection_loc].wave_a;
-        u8 *wave_b = pat->ch3.params[trig_selection_loc].wave_b;
+        u8 *wave_a = params->wave_a;
+        u8 *wave_b = params->wave_b;
 
         size_t x = PARAMS_START_X;
         size_t y = PARAMS_START_Y + 13;
@@ -617,16 +582,10 @@ draw_parameters_wave(void) {
         draw_line(x, y + 17, x + 30, y + 17, COL_FG);
         txt_drawf_small("mode", x + 6, y, COL_FG);
 
-        switch (pat->ch3.params[trig_selection_loc].wave_mode) {
-            case 0: {
-                txt_drawf("A", x + 12, y + 7, COL_FG);
-            } break;
-            case 1: {
-                txt_drawf("B", x + 12, y + 7, COL_FG);
-            } break;
-            case 2: {
-                txt_drawf("A+B", x + 6, y + 7, COL_FG);
-            } break;
+        switch (params->wave_mode) {
+            case 0: { txt_drawf("A", x + 12, y + 7, COL_FG); } break;
+            case 1: { txt_drawf("B", x + 12, y + 7, COL_FG); } break;
+            case 2: { txt_drawf("A+B", x + 6, y + 7, COL_FG); } break;
         }
     }
 
@@ -641,22 +600,12 @@ draw_parameters_wave(void) {
         draw_line(x, y + 20, x + 30, y + 20, COL_FG);
         txt_drawf_small("vol", x + 8, y + 3, COL_FG);
 
-        switch (pat->ch3.params[trig_selection_loc].wave_volume) {
-            case 0: {
-                txt_drawf("0", x + 12, y + 10, COL_FG);
-            } break;
-            case 1: {
-                txt_drawf("25", x + 9, y + 10, COL_FG);
-            } break;
-            case 2: {
-                txt_drawf("50", x + 9, y + 10, COL_FG);
-            } break;
-            case 3: {
-                txt_drawf("75", x + 9, y + 10, COL_FG);
-            } break;
-            case 4: {
-                txt_drawf("100", x + 6, y + 10, COL_FG);
-            } break;
+        switch (params->wave_volume) {
+            case 0: { txt_drawf("0", x + 12, y + 10, COL_FG); } break;
+            case 1: { txt_drawf("25", x + 9, y + 10, COL_FG); } break;
+            case 2: { txt_drawf("50", x + 9, y + 10, COL_FG); } break;
+            case 3: { txt_drawf("75", x + 9, y + 10, COL_FG); } break;
+            case 4: { txt_drawf("100", x + 6, y + 10, COL_FG); } break;
         }
     }
 }
@@ -737,18 +686,10 @@ draw_parameters_square(ChannelSquareParams *params, bool sweep) {
             txt_drawf_small("duty", x + 3, y + 3, COL_FG);
 
             switch (params->duty_cycle) {
-                case 0: {
-                    txt_drawf("12", x + 6, y + 10, COL_FG);
-                } break;
-                case 1: {
-                    txt_drawf("25", x + 6, y + 10, COL_FG);
-                } break;
-                case 2: {
-                    txt_drawf("50", x + 6, y + 10, COL_FG);
-                } break;
-                case 3: {
-                    txt_drawf("75", x + 6, y + 10, COL_FG);
-                } break;
+                case 0: { txt_drawf("12", x + 6, y + 10, COL_FG); } break;
+                case 1: { txt_drawf("25", x + 6, y + 10, COL_FG); } break;
+                case 2: { txt_drawf("50", x + 6, y + 10, COL_FG); } break;
+                case 3: { txt_drawf("75", x + 6, y + 10, COL_FG); } break;
             }
         }
     }
@@ -796,54 +737,22 @@ draw_parameters_square(ChannelSquareParams *params, bool sweep) {
             txt_drawf_small("vol", x + 5, y + 3, COL_FG);
 
             switch (params->env_volume) {
-                case 0: {
-                    txt_drawf("0", x + 9, y + 10, COL_FG);
-                } break;
-                case 1: {
-                    txt_drawf("6", x + 9, y + 10, COL_FG);
-                } break;
-                case 2: {
-                    txt_drawf("13", x + 6, y + 10, COL_FG);
-                } break;
-                case 3: {
-                    txt_drawf("20", x + 6, y + 10, COL_FG);
-                } break;
-                case 4: {
-                    txt_drawf("26", x + 6, y + 10, COL_FG);
-                } break;
-                case 5: {
-                    txt_drawf("33", x + 6, y + 10, COL_FG);
-                } break;
-                case 6: {
-                    txt_drawf("40", x + 6, y + 10, COL_FG);
-                } break;
-                case 7: {
-                    txt_drawf("46", x + 6, y + 10, COL_FG);
-                } break;
-                case 8: {
-                    txt_drawf("53", x + 6, y + 10, COL_FG);
-                } break;
-                case 9: {
-                    txt_drawf("60", x + 6, y + 10, COL_FG);
-                } break;
-                case 10: {
-                    txt_drawf("66", x + 6, y + 10, COL_FG);
-                } break;
-                case 11: {
-                    txt_drawf("73", x + 6, y + 10, COL_FG);
-                } break;
-                case 12: {
-                    txt_drawf("80", x + 6, y + 10, COL_FG);
-                } break;
-                case 13: {
-                    txt_drawf("86", x + 6, y + 10, COL_FG);
-                } break;
-                case 14: {
-                    txt_drawf("93", x + 6, y + 10, COL_FG);
-                } break;
-                case 15: {
-                    txt_drawf("100", x + 3, y + 10, COL_FG);
-                } break;
+                case 0: { txt_drawf("0", x + 9, y + 10, COL_FG); } break;
+                case 1: { txt_drawf("6", x + 9, y + 10, COL_FG); } break;
+                case 2: { txt_drawf("13", x + 6, y + 10, COL_FG); } break;
+                case 3: { txt_drawf("20", x + 6, y + 10, COL_FG); } break;
+                case 4: { txt_drawf("26", x + 6, y + 10, COL_FG); } break;
+                case 5: { txt_drawf("33", x + 6, y + 10, COL_FG); } break;
+                case 6: { txt_drawf("40", x + 6, y + 10, COL_FG); } break;
+                case 7: { txt_drawf("46", x + 6, y + 10, COL_FG); } break;
+                case 8: { txt_drawf("53", x + 6, y + 10, COL_FG); } break;
+                case 9: { txt_drawf("60", x + 6, y + 10, COL_FG); } break;
+                case 10: { txt_drawf("66", x + 6, y + 10, COL_FG); } break;
+                case 11: { txt_drawf("73", x + 6, y + 10, COL_FG); } break;
+                case 12: { txt_drawf("80", x + 6, y + 10, COL_FG); } break;
+                case 13: { txt_drawf("86", x + 6, y + 10, COL_FG); } break;
+                case 14: { txt_drawf("93", x + 6, y + 10, COL_FG); } break;
+                case 15: { txt_drawf("100", x + 3, y + 10, COL_FG); } break;
             }
         }
 
@@ -861,12 +770,8 @@ draw_parameters_square(ChannelSquareParams *params, bool sweep) {
             char arr_up[2] = { 0x19, 0 };
             char arr_down[2] = { 0x18, 0 };
             switch (params->env_direction) {
-                case 0: {
-                    txt_drawf(arr_up, x + 9, y + 11, COL_FG);
-                } break;
-                case 1: {
-                    txt_drawf(arr_down, x + 9, y + 11, COL_FG);
-                } break;
+                case 0: { txt_drawf(arr_up, x + 9, y + 11, COL_FG); } break;
+                case 1: { txt_drawf(arr_down, x + 9, y + 11, COL_FG); } break;
             }
         }
 
@@ -882,30 +787,14 @@ draw_parameters_square(ChannelSquareParams *params, bool sweep) {
             txt_drawf_small("time", x + 3, y + 3, COL_FG);
 
             switch (params->env_time) {
-                case 0: {
-                    txt_drawf("0", x + 9, y + 10, COL_FG);
-                } break;
-                case 1: {
-                    txt_drawf("14", x + 6, y + 10, COL_FG);
-                } break;
-                case 2: {
-                    txt_drawf("28", x + 6, y + 10, COL_FG);
-                } break;
-                case 3: {
-                    txt_drawf("42", x + 6, y + 10, COL_FG);
-                } break;
-                case 4: {
-                    txt_drawf("57", x + 6, y + 10, COL_FG);
-                } break;
-                case 5: {
-                    txt_drawf("71", x + 6, y + 10, COL_FG);
-                } break;
-                case 6: {
-                    txt_drawf("85", x + 6, y + 10, COL_FG);
-                } break;
-                case 7: {
-                    txt_drawf("100", x + 3, y + 10, COL_FG);
-                } break;
+                case 0: { txt_drawf("0", x + 9, y + 10, COL_FG); } break;
+                case 1: { txt_drawf("14", x + 6, y + 10, COL_FG); } break;
+                case 2: { txt_drawf("28", x + 6, y + 10, COL_FG); } break;
+                case 3: { txt_drawf("42", x + 6, y + 10, COL_FG); } break;
+                case 4: { txt_drawf("57", x + 6, y + 10, COL_FG); } break;
+                case 5: { txt_drawf("71", x + 6, y + 10, COL_FG); } break;
+                case 6: { txt_drawf("85", x + 6, y + 10, COL_FG); } break;
+                case 7: { txt_drawf("100", x + 3, y + 10, COL_FG); } break;
             }
         }
     }
@@ -922,30 +811,14 @@ draw_parameters_square(ChannelSquareParams *params, bool sweep) {
         txt_drawf_small("num", x + 5, y + 3, COL_FG);
 
         switch (params->sweep_number) {
-            case 0: {
-                txt_drawf("0", x + 9, y + 10, COL_FG);
-            } break;
-            case 1: {
-                txt_drawf("1", x + 9, y + 10, COL_FG);
-            } break;
-            case 2: {
-                txt_drawf("2", x + 9, y + 10, COL_FG);
-            } break;
-            case 3: {
-                txt_drawf("3", x + 9, y + 10, COL_FG);
-            } break;
-            case 4: {
-                txt_drawf("4", x + 9, y + 10, COL_FG);
-            } break;
-            case 5: {
-                txt_drawf("5", x + 9, y + 10, COL_FG);
-            } break;
-            case 6: {
-                txt_drawf("6", x + 9, y + 10, COL_FG);
-            } break;
-            case 7: {
-                txt_drawf("7", x + 9, y + 10, COL_FG);
-            } break;
+            case 0: { txt_drawf("0", x + 9, y + 10, COL_FG); } break;
+            case 1: { txt_drawf("1", x + 9, y + 10, COL_FG); } break;
+            case 2: { txt_drawf("2", x + 9, y + 10, COL_FG); } break;
+            case 3: { txt_drawf("3", x + 9, y + 10, COL_FG); } break;
+            case 4: { txt_drawf("4", x + 9, y + 10, COL_FG); } break;
+            case 5: { txt_drawf("5", x + 9, y + 10, COL_FG); } break;
+            case 6: { txt_drawf("6", x + 9, y + 10, COL_FG); } break;
+            case 7: { txt_drawf("7", x + 9, y + 10, COL_FG); } break;
         }
     }
 
@@ -961,30 +834,14 @@ draw_parameters_square(ChannelSquareParams *params, bool sweep) {
         txt_drawf_small("time", x + 3, y + 3, COL_FG);
 
         switch (params->sweep_time) {
-            case 0: {
-                txt_drawf("0", x + 9, y + 10, COL_FG);
-            } break;
-            case 1: {
-                txt_drawf("1", x + 9, y + 10, COL_FG);
-            } break;
-            case 2: {
-                txt_drawf("2", x + 9, y + 10, COL_FG);
-            } break;
-            case 3: {
-                txt_drawf("3", x + 9, y + 10, COL_FG);
-            } break;
-            case 4: {
-                txt_drawf("4", x + 9, y + 10, COL_FG);
-            } break;
-            case 5: {
-                txt_drawf("5", x + 9, y + 10, COL_FG);
-            } break;
-            case 6: {
-                txt_drawf("6", x + 9, y + 10, COL_FG);
-            } break;
-            case 7: {
-                txt_drawf("7", x + 9, y + 10, COL_FG);
-            } break;
+            case 0: { txt_drawf("0", x + 9, y + 10, COL_FG); } break;
+            case 1: { txt_drawf("1", x + 9, y + 10, COL_FG); } break;
+            case 2: { txt_drawf("2", x + 9, y + 10, COL_FG); } break;
+            case 3: { txt_drawf("3", x + 9, y + 10, COL_FG); } break;
+            case 4: { txt_drawf("4", x + 9, y + 10, COL_FG); } break;
+            case 5: { txt_drawf("5", x + 9, y + 10, COL_FG); } break;
+            case 6: { txt_drawf("6", x + 9, y + 10, COL_FG); } break;
+            case 7: { txt_drawf("7", x + 9, y + 10, COL_FG); } break;
         }
     }
 
@@ -1002,12 +859,8 @@ draw_parameters_square(ChannelSquareParams *params, bool sweep) {
         char arr_up[2] = { 0x19, 0 };
         char arr_down[2] = { 0x18, 0 };
         switch (params->sweep_direction) {
-            case 0: {
-                txt_drawf(arr_up, x + 9, y + 11, COL_FG);
-            } break;
-            case 1: {
-                txt_drawf(arr_down, x + 9, y + 11, COL_FG);
-            } break;
+            case 0: { txt_drawf(arr_up, x + 9, y + 11, COL_FG); } break;
+            case 1: { txt_drawf(arr_down, x + 9, y + 11, COL_FG); } break;
         }
     }
 
@@ -1024,10 +877,8 @@ draw_parameters_square(ChannelSquareParams *params, bool sweep) {
 }
 
 void
-draw_parameters_noise(void) {
+draw_parameters_noise(ChannelNoiseParams* params) {
     size_t x_offset = 30;
-    Pattern *pat = &patterns[pattern_selection_loc];
-    ChannelNoiseParams *params = &pat->ch4.params[trig_selection_loc];
 
     // Bit mode.
     {
@@ -1043,12 +894,8 @@ draw_parameters_noise(void) {
             txt_drawf_small("mode", x + 3, y + 3, COL_FG);
 
             switch (params->bit_mode) {
-                case 0: {
-                    txt_drawf("A", x + 9, y + 10, COL_FG);
-                } break;
-                case 1: {
-                    txt_drawf("B", x + 9, y + 10, COL_FG);
-                } break;
+                case 0: { txt_drawf("A", x + 9, y + 10, COL_FG); } break;
+                case 1: { txt_drawf("B", x + 9, y + 10, COL_FG); } break;
             }
         }
     }
@@ -1096,54 +943,22 @@ draw_parameters_noise(void) {
             txt_drawf_small("vol", x + 5, y + 3, COL_FG);
 
             switch (params->env_volume) {
-                case 0: {
-                    txt_drawf("0", x + 9, y + 10, COL_FG);
-                } break;
-                case 1: {
-                    txt_drawf("6", x + 9, y + 10, COL_FG);
-                } break;
-                case 2: {
-                    txt_drawf("13", x + 6, y + 10, COL_FG);
-                } break;
-                case 3: {
-                    txt_drawf("20", x + 6, y + 10, COL_FG);
-                } break;
-                case 4: {
-                    txt_drawf("26", x + 6, y + 10, COL_FG);
-                } break;
-                case 5: {
-                    txt_drawf("33", x + 6, y + 10, COL_FG);
-                } break;
-                case 6: {
-                    txt_drawf("40", x + 6, y + 10, COL_FG);
-                } break;
-                case 7: {
-                    txt_drawf("46", x + 6, y + 10, COL_FG);
-                } break;
-                case 8: {
-                    txt_drawf("53", x + 6, y + 10, COL_FG);
-                } break;
-                case 9: {
-                    txt_drawf("60", x + 6, y + 10, COL_FG);
-                } break;
-                case 10: {
-                    txt_drawf("66", x + 6, y + 10, COL_FG);
-                } break;
-                case 11: {
-                    txt_drawf("73", x + 6, y + 10, COL_FG);
-                } break;
-                case 12: {
-                    txt_drawf("80", x + 6, y + 10, COL_FG);
-                } break;
-                case 13: {
-                    txt_drawf("86", x + 6, y + 10, COL_FG);
-                } break;
-                case 14: {
-                    txt_drawf("93", x + 6, y + 10, COL_FG);
-                } break;
-                case 15: {
-                    txt_drawf("100", x + 3, y + 10, COL_FG);
-                } break;
+                case 0: { txt_drawf("0", x + 9, y + 10, COL_FG); } break;
+                case 1: { txt_drawf("6", x + 9, y + 10, COL_FG); } break;
+                case 2: { txt_drawf("13", x + 6, y + 10, COL_FG); } break;
+                case 3: { txt_drawf("20", x + 6, y + 10, COL_FG); } break;
+                case 4: { txt_drawf("26", x + 6, y + 10, COL_FG); } break;
+                case 5: { txt_drawf("33", x + 6, y + 10, COL_FG); } break;
+                case 6: { txt_drawf("40", x + 6, y + 10, COL_FG); } break;
+                case 7: { txt_drawf("46", x + 6, y + 10, COL_FG); } break;
+                case 8: { txt_drawf("53", x + 6, y + 10, COL_FG); } break;
+                case 9: { txt_drawf("60", x + 6, y + 10, COL_FG); } break;
+                case 10: { txt_drawf("66", x + 6, y + 10, COL_FG); } break;
+                case 11: { txt_drawf("73", x + 6, y + 10, COL_FG); } break;
+                case 12: { txt_drawf("80", x + 6, y + 10, COL_FG); } break;
+                case 13: { txt_drawf("86", x + 6, y + 10, COL_FG); } break;
+                case 14: { txt_drawf("93", x + 6, y + 10, COL_FG); } break;
+                case 15: { txt_drawf("100", x + 3, y + 10, COL_FG); } break;
             }
         }
 
@@ -1182,30 +997,14 @@ draw_parameters_noise(void) {
             txt_drawf_small("time", x + 3, y + 3, COL_FG);
 
             switch (params->env_time) {
-                case 0: {
-                    txt_drawf("0", x + 9, y + 10, COL_FG);
-                } break;
-                case 1: {
-                    txt_drawf("14", x + 6, y + 10, COL_FG);
-                } break;
-                case 2: {
-                    txt_drawf("28", x + 6, y + 10, COL_FG);
-                } break;
-                case 3: {
-                    txt_drawf("42", x + 6, y + 10, COL_FG);
-                } break;
-                case 4: {
-                    txt_drawf("57", x + 6, y + 10, COL_FG);
-                } break;
-                case 5: {
-                    txt_drawf("71", x + 6, y + 10, COL_FG);
-                } break;
-                case 6: {
-                    txt_drawf("85", x + 6, y + 10, COL_FG);
-                } break;
-                case 7: {
-                    txt_drawf("100", x + 3, y + 10, COL_FG);
-                } break;
+                case 0: { txt_drawf("0", x + 9, y + 10, COL_FG); } break;
+                case 1: { txt_drawf("14", x + 6, y + 10, COL_FG); } break;
+                case 2: { txt_drawf("28", x + 6, y + 10, COL_FG); } break;
+                case 3: { txt_drawf("42", x + 6, y + 10, COL_FG); } break;
+                case 4: { txt_drawf("57", x + 6, y + 10, COL_FG); } break;
+                case 5: { txt_drawf("71", x + 6, y + 10, COL_FG); } break;
+                case 6: { txt_drawf("85", x + 6, y + 10, COL_FG); } break;
+                case 7: { txt_drawf("100", x + 3, y + 10, COL_FG); } break;
             }
         }
     }
@@ -1221,27 +1020,32 @@ draw_parameters_noise(void) {
 void
 draw_parameters(void) {
     clear_parameters();
-    if (input_handler != handle_trigger_selection &&
-            input_handler != handle_param_selection_sq1 &&
-            input_handler != handle_param_selection_sq2 &&
-            input_handler != handle_param_selection_wave &&
-            input_handler != handle_param_selection_noise) {
+    Pattern *pat = &patterns[pattern_selection_loc];
+    if (input_handler == handle_trigger_selection ||
+            input_handler == handle_param_selection_sq1 ||
+            input_handler == handle_param_selection_sq2 ||
+            input_handler == handle_param_selection_wave ||
+            input_handler == handle_param_selection_noise) {
+        switch (channel_selection_loc) {
+            case 0: { draw_parameters_square(&pat->ch1.params[trig_selection_loc], true); } break;
+            case 1: { draw_parameters_square(&pat->ch2.params[trig_selection_loc], false); } break;
+            case 2: { draw_parameters_wave(&pat->ch3.params[trig_selection_loc]); } break;
+            case 3: { draw_parameters_noise(&pat->ch4.params[trig_selection_loc]); } break;
+        }
         return;
     }
-    Pattern *pat = &patterns[pattern_selection_loc];
-    switch (channel_selection_loc) {
-        case 0: {
-            draw_parameters_square(&pat->ch1.params[trig_selection_loc], true);
-        } break;
-        case 1: {
-            draw_parameters_square(&pat->ch2.params[trig_selection_loc], false);
-        } break;
-        case 2: {
-            draw_parameters_wave();
-        } break;
-        case 3: {
-            draw_parameters_noise();
-        } break;
+    if (input_handler == handle_channel_selection ||
+            input_handler == handle_param_selection_ch1 ||
+            input_handler == handle_param_selection_ch2 ||
+            input_handler == handle_param_selection_ch3 ||
+            input_handler == handle_param_selection_ch4) {
+        switch (channel_selection_loc) {
+            case 0: { draw_parameters_square(&pat->ch1.params[16], true); } break;
+            case 1: { draw_parameters_square(&pat->ch2.params[16], false); } break;
+            case 2: { draw_parameters_wave(&pat->ch3.params[16]); } break;
+            case 3: { draw_parameters_noise(&pat->ch4.params[16]); } break;
+        }
+        return;
     }
 }
 
diff --git a/src/globals.c b/src/globals.c
index 34e9bb5..8ce79d5 100644
--- a/src/globals.c
+++ b/src/globals.c
@@ -97,7 +97,9 @@ enum RIGHT_COL_LOC {
 // Input handling works using a FSM. The input handler is switched to whichever
 // function controls each section. For example, channel selection or trigger
 // selection.
-void (*input_handler)(void);
+typedef void (*InputHandler)(void);
+
+InputHandler input_handler;
 
 void handle_trigger_selection(void);
 void handle_channel_selection(void);
@@ -107,3 +109,7 @@ void handle_param_selection_sq2(void);
 void handle_param_selection_wave(void);
 void handle_param_selection_noise(void);
 void handle_right_col_selection(void);
+void handle_param_selection_ch1(void);
+void handle_param_selection_ch2(void);
+void handle_param_selection_ch3(void);
+void handle_param_selection_ch4(void);
diff --git a/src/patterns.c b/src/patterns.c
index 09f7bae..dbd9c9f 100644
--- a/src/patterns.c
+++ b/src/patterns.c
@@ -34,19 +34,19 @@ typedef struct ChannelNoiseParams {
 typedef struct ChannelSquare {
     bool active;
     TriggerNote notes[16];
-    ChannelSquareParams params[16];
+    ChannelSquareParams params[17];
 } ChannelSquare;
 
 typedef struct ChannelWave {
     bool active;
     TriggerNote notes[16];
-    ChannelWaveParams params[16];
+    ChannelWaveParams params[17];
 } ChannelWave;
 
 typedef struct ChannelNoise {
     bool active;
     TriggerNote notes[16];
-    ChannelNoiseParams params[16];
+    ChannelNoiseParams params[17];
 } ChannelNoise;
 
 typedef struct Pattern {
diff --git a/src/sequencer.c b/src/sequencer.c
index 8f2b183..1280f5f 100644
--- a/src/sequencer.c
+++ b/src/sequencer.c
@@ -209,6 +209,14 @@ handle_channel_selection(void) {
     } else if (key_tap(KEY_A)) {
         if (key_hold(KEY_SELECT)) {
             clipboard_paste();
+        } else {
+            switch (channel_selection_loc) {
+                case 0: { input_handler = handle_param_selection_ch1; } break;
+                case 1: { input_handler = handle_param_selection_ch2; } break;
+                case 2: { input_handler = handle_param_selection_ch3; } break;
+                case 3: { input_handler = handle_param_selection_ch4; } break;
+            }
+            redraw_params = true;
         }
     } else if (key_tap(KEY_L)) {
         s32 inc = -1;
@@ -222,6 +230,7 @@ handle_channel_selection(void) {
                 case 1: { trig = &pat->ch2.notes[i]; } break;
                 case 2: { trig = &pat->ch3.notes[i]; } break;
                 case 3: { trig = &pat->ch4.notes[i]; } break;
+                default: {trig = &pat->ch1.notes[i]; } break;
             }
             trig->note = MAX((s32)trig->note + inc, (s32)NOTE_C_2);
         }
@@ -238,6 +247,7 @@ handle_channel_selection(void) {
                 case 1: { trig = &pat->ch2.notes[i]; } break;
                 case 2: { trig = &pat->ch3.notes[i]; } break;
                 case 3: { trig = &pat->ch4.notes[i]; } break;
+                default: {trig = &pat->ch1.notes[i]; } break;
             }
             trig->note = MIN((s32)trig->note + inc, (s32)NOTE_C_8 - 1);
         }
@@ -258,6 +268,7 @@ handle_channel_selection(void) {
             channel_selection_loc = MAX(channel_selection_loc - 1, 0);
         }
         redraw_trigs = true;
+        redraw_params = true;
     } else if (key_tap(KEY_DOWN)) {
         if (channel_selection_loc == SEQ_N_CHANNELS - 1) {
             channel_selection_loc = 0;
@@ -265,6 +276,7 @@ handle_channel_selection(void) {
             channel_selection_loc = MIN(channel_selection_loc + 1, SEQ_N_CHANNELS);
         }
         redraw_trigs = true;
+        redraw_params = true;
     }
 }
 
@@ -457,10 +469,10 @@ handle_pattern_selection(void) {
 }
 
 void
-handle_param_selection_sq1(void) {
+set_param_selection_sq1(size_t i, InputHandler return_handler) {
     // Go back to trigger selection.
     if (key_released(KEY_A)) {
-        input_handler = handle_trigger_selection;
+        input_handler = return_handler;
         redraw_params = true;
         return;
     }
@@ -518,7 +530,7 @@ handle_param_selection_sq1(void) {
             inc = 1;
         }
         Pattern *pat = &patterns[pattern_selection_loc];
-        ChannelSquareParams *params = &pat->ch1.params[trig_selection_loc];
+        ChannelSquareParams *params = &pat->ch1.params[i];
         switch (param_selection_loc) {
             case 0: {
                 params->duty_cycle = CLAMP(params->duty_cycle + inc, 0, 3);
@@ -547,10 +559,10 @@ handle_param_selection_sq1(void) {
 }
 
 void
-handle_param_selection_sq2(void) {
+set_param_selection_sq2(size_t i, InputHandler return_handler) {
     // Go back to trigger selection.
     if (key_released(KEY_A)) {
-        input_handler = handle_trigger_selection;
+        input_handler = return_handler;
         redraw_params = true;
         return;
     }
@@ -577,7 +589,7 @@ handle_param_selection_sq2(void) {
             inc = 1;
         }
         Pattern *pat = &patterns[pattern_selection_loc];
-        ChannelSquareParams *params = &pat->ch2.params[trig_selection_loc];
+        ChannelSquareParams *params = &pat->ch2.params[i];
         switch (param_selection_loc) {
             case 0: {
                 params->duty_cycle = CLAMP(params->duty_cycle + inc, 0, 3);
@@ -597,12 +609,12 @@ handle_param_selection_sq2(void) {
 }
 
 void
-handle_param_selection_wave(void) {
+set_param_selection_wave(size_t i, InputHandler return_handler) {
     Pattern *pat = &patterns[pattern_selection_loc];
 
     // Go back to trigger selection.
     if (key_released(KEY_A)) {
-        input_handler = handle_trigger_selection;
+        input_handler = return_handler;
         redraw_params = true;
         return;
     }
@@ -706,7 +718,7 @@ handle_param_selection_wave(void) {
         if (param_selection_loc < 32) {
             // Draw on wave a.
             u8 byte_number = param_selection_loc / 2;
-            u8 *byte = &pat->ch3.params[trig_selection_loc].wave_a;
+            u8 *byte = &pat->ch3.params[i].wave_a;
             byte += byte_number;
             if (odd) {
                 *byte = (~0xF & *byte) | ((*byte + inc) & 0xF);
@@ -716,7 +728,7 @@ handle_param_selection_wave(void) {
         } else if (param_selection_loc < 64){
             // Draw on wave b.
             u8 byte_number = (param_selection_loc - 32) / 2;
-            u8 *byte = &pat->ch3.params[trig_selection_loc].wave_b;
+            u8 *byte = &pat->ch3.params[i].wave_b;
             byte += byte_number;
             if (odd) {
                 *byte = (~0xF & *byte) | ((*byte + inc) & 0xF);
@@ -725,8 +737,8 @@ handle_param_selection_wave(void) {
             }
         } else if (param_selection_loc < 72) {
             // Copy default waves.
-            u32 *wave_a = &pat->ch3.params[trig_selection_loc].wave_a;
-            u32 *wave_b = &pat->ch3.params[trig_selection_loc].wave_b;
+            u32 *wave_a = &pat->ch3.params[i].wave_a;
+            u32 *wave_b = &pat->ch3.params[i].wave_b;
             switch (param_selection_loc) {
                 case 64: {
                     memcpy32(wave_a, sine_wave, 16);
@@ -760,10 +772,10 @@ handle_param_selection_wave(void) {
                 } break;
             }
         } else if (param_selection_loc == 72) {
-            u8 *wave_mode = &pat->ch3.params[trig_selection_loc].wave_mode;
+            u8 *wave_mode = &pat->ch3.params[i].wave_mode;
             *wave_mode = CLAMP(*wave_mode + inc, 0, 2);
         } else if (param_selection_loc == 73) {
-            u8 *wave_volume = &pat->ch3.params[trig_selection_loc].wave_volume;
+            u8 *wave_volume = &pat->ch3.params[i].wave_volume;
             *wave_volume = CLAMP(*wave_volume + inc, 0, 4);
         }
         redraw_params = true;
@@ -771,10 +783,11 @@ handle_param_selection_wave(void) {
 }
 
 void
-handle_param_selection_noise(void) {
+set_param_selection_noise(size_t i, InputHandler return_handler) {
     // Go back to trigger selection.
     if (key_released(KEY_A)) {
-        input_handler = handle_trigger_selection;
+        input_handler = return_handler;
+        redraw_params = true;
         return;
     }
 
@@ -788,6 +801,7 @@ handle_param_selection_noise(void) {
             inc = -1;
         }
         param_selection_loc = CLAMP(loc + inc, 0, 3);
+        redraw_params = true;
     }
 
     // Adjust parameter.
@@ -799,7 +813,7 @@ handle_param_selection_noise(void) {
             inc = 1;
         }
         Pattern *pat = &patterns[pattern_selection_loc];
-        ChannelNoiseParams *params = &pat->ch4.params[trig_selection_loc];
+        ChannelNoiseParams *params = &pat->ch4.params[i];
         switch (param_selection_loc) {
             case 0: {
                 params->bit_mode = CLAMP(params->bit_mode + inc, 0, 1);
@@ -819,6 +833,46 @@ handle_param_selection_noise(void) {
 }
 
 void
+handle_param_selection_ch1() {
+    set_param_selection_sq1(16, handle_channel_selection);
+}
+
+void
+handle_param_selection_ch2() {
+    set_param_selection_sq2(16, handle_channel_selection);
+}
+
+void
+handle_param_selection_ch3() {
+    set_param_selection_wave(16, handle_channel_selection);
+}
+
+void
+handle_param_selection_ch4() {
+    set_param_selection_noise(16, handle_channel_selection);
+}
+
+void
+handle_param_selection_sq1() {
+    set_param_selection_sq1(trig_selection_loc, handle_trigger_selection);
+}
+
+void
+handle_param_selection_sq2() {
+    set_param_selection_sq2(trig_selection_loc, handle_trigger_selection);
+}
+
+void
+handle_param_selection_wave() {
+    set_param_selection_wave(trig_selection_loc, handle_trigger_selection);
+}
+
+void
+handle_param_selection_noise() {
+    set_param_selection_noise(trig_selection_loc, handle_trigger_selection);
+}
+
+void
 handle_trigger_selection(void) {
     TriggerNote *trig = get_current_trig();
 
@@ -886,18 +940,10 @@ handle_trigger_selection(void) {
         } else {
             // Switch to parameter selection.
             switch (channel_selection_loc) {
-                case 0: {
-                    input_handler = handle_param_selection_sq1;
-                } break;
-                case 1: {
-                    input_handler = handle_param_selection_sq2;
-                } break;
-                case 2: {
-                    input_handler = handle_param_selection_wave;
-                } break;
-                case 3: {
-                    input_handler = handle_param_selection_noise;
-                } break;
+                case 0: { input_handler = handle_param_selection_sq1; } break;
+                case 1: { input_handler = handle_param_selection_sq2; } break;
+                case 2: { input_handler = handle_param_selection_wave; } break;
+                case 3: { input_handler = handle_param_selection_noise; } break;
             }
             redraw_params = true;
             redraw_piano_note = true;