Amend button descriptions in game selection menu

patches/linker/link_ntsc10.ld

@@ -104,3 +104,11 @@ ntsc10_EXIDeselect = 0x81335838;
 ntsc10_EXISync = 0x81335134;
 ntsc10_EXIImm = 0x81334d4c;
 ntsc10_EXIImmEx = 0x81334fa8;
+
+ntsc10_all_element_alphas = 0x81465a9c;
+ntsc10_update_element_alpha = 0x8130aa58;
+
+ntsc10_update_button_alphas = 0x81311a98;
+
+ntsc10_current_pal_buttons_language = 0;
+ntsc10_pal_button_language_elements = 0;

patches/linker/link_ntsc11.ld

@@ -104,3 +104,11 @@ ntsc11_EXIDeselect = 0x8135b298;
 ntsc11_EXISync = 0x8135ab5c;
 ntsc11_EXIImm = 0x8135a774;
 ntsc11_EXIImmEx = 0x8135a9d0;
+
+ntsc11_all_element_alphas = 0x8148a21c;
+ntsc11_update_element_alpha = 0x8130a964;
+
+ntsc11_update_button_alphas = 0x81311ce8;
+
+ntsc11_current_pal_buttons_language = 0;
+ntsc11_pal_button_language_elements = 0;

patches/linker/link_ntsc12_001.ld

@@ -99,3 +99,11 @@ ntsc12_001_EXIDeselect = 0x81364790;
 ntsc12_001_EXISync = 0x81363f4c;
 ntsc12_001_EXIImm = 0x81363b64;
 ntsc12_001_EXIImmEx = 0x81363dc0;
+
+ntsc12_001_all_element_alphas = 0x8148b7fc;
+ntsc12_001_update_element_alpha = 0x8130acd8;
+
+ntsc12_001_update_button_alphas = 0x81312080;
+
+ntsc12_001_current_pal_buttons_language = 0;
+ntsc12_001_pal_button_language_elements = 0;

patches/linker/link_ntsc12_101.ld

@@ -99,3 +99,11 @@ ntsc12_101_EXIDeselect = 0x813648f4;
 ntsc12_101_EXISync = 0x813640b0;
 ntsc12_101_EXIImm = 0x81363cc8;
 ntsc12_101_EXIImmEx = 0x81363f24;
+
+ntsc12_101_all_element_alphas = 0x8148bc9c;
+ntsc12_101_update_element_alpha = 0x8130acf0;
+
+ntsc12_101_update_button_alphas = 0x81312098;
+
+ntsc12_101_current_pal_buttons_language = 0;
+ntsc12_101_pal_button_language_elements = 0;

patches/linker/link_pal10.ld

@@ -101,3 +101,11 @@ pal10_EXIDeselect = 0x8135e878;
 pal10_EXISync = 0x8135e13c;
 pal10_EXIImm = 0x8135dd54;
 pal10_EXIImmEx = 0x8135dfb0;
+
+pal10_all_element_alphas = 0x814b611c;
+pal10_update_element_alpha = 0x8130a87c;
+
+pal10_update_button_alphas = 0x81312580;
+
+pal10_current_pal_buttons_language = 0x814ad438;
+pal10_pal_button_language_elements = 0x814b62fc;

patches/linker/link_pal11.ld

@@ -99,3 +99,11 @@ pal11_EXIDeselect = 0x8135b1b8;
 pal11_EXISync = 0x8135aa7c;
 pal11_EXIImm = 0x8135a694;
 pal11_EXIImmEx = 0x8135a8f0;
+
+pal11_all_element_alphas = 0x81484edc;
+pal11_update_element_alpha = 0x8130a964;
+
+pal11_update_button_alphas = 0x81311c14;
+
+pal11_current_pal_buttons_language = 0;
+pal11_pal_button_language_elements = 0;

patches/linker/link_pal12.ld

@@ -100,3 +100,11 @@ pal12_EXIDeselect = 0x81367c6c;
 pal12_EXISync = 0x81367428;
 pal12_EXIImm = 0x81367040;
 pal12_EXIImmEx = 0x8136729c;
+
+pal12_all_element_alphas = 0x814b78dc;
+pal12_update_element_alpha = 0x8130a9bc;
+
+pal12_update_button_alphas = 0x813126c0;
+
+pal12_current_pal_buttons_language = 0x814af730;
+pal12_pal_button_language_elements = 0x814b7abc;

patches/source/button_descriptions.c

@@ -0,0 +1,79 @@
+#include "button_descriptions.h"
+
+#include "menu.h"
+#include "attr.h"
+#include "reloc.h"
+
+#define NUM_PAL_LANGUAGES 6
+
+__attribute_reloc__ void (*update_button_alphas)();
+
+__attribute_reloc__ all_element_alphas_t* all_element_alphas;
+
+__attribute_reloc__ u16 *current_pal_buttons_language;
+__attribute_reloc__ element_alpha_state_t *pal_button_language_elements;
+
+static void update_gameplay_button_text() {
+    // Disable button descriptions used by the outer menu
+    update_element_alpha(&all_element_alphas->text.one_column.menu_selection, element_alpha_hidden);
+    update_element_alpha(&all_element_alphas->text.two_columns.left_cancel, element_alpha_hidden);
+    update_element_alpha(&all_element_alphas->text.two_columns.right_confirm, element_alpha_hidden);
+
+    // And also disable button descriptions used by other menus
+    update_element_alpha(&all_element_alphas->text.three_columns.left_change, element_alpha_hidden);
+    update_element_alpha(&all_element_alphas->text.three_columns.centre_finish, element_alpha_hidden);
+
+    // Show 'B: Cancel' on both the loader and start screens
+    update_element_alpha(&all_element_alphas->text.three_columns.centre_cancel, element_alpha_visible);
+
+    // Show 'Control Stick: Select' and 'A: Confirm' just on the loader menu
+    update_element_alpha(&all_element_alphas->text.three_columns.left_select, current_gameselect_state == SUBMENU_GAMESELECT_LOADER ? element_alpha_visible : element_alpha_hidden);
+    update_element_alpha(&all_element_alphas->text.three_columns.right_confirm, current_gameselect_state == SUBMENU_GAMESELECT_LOADER ? element_alpha_visible : element_alpha_hidden);
+}
+
+static void update_gameplay_button_icons() {
+    // Disable button icons used by the outer menu
+    update_element_alpha(&all_element_alphas->icons.one_column.control_stick, element_alpha_hidden);
+    update_element_alpha(&all_element_alphas->icons.two_columns.left_b_button, element_alpha_hidden);
+    update_element_alpha(&all_element_alphas->icons.two_columns.right_a_button, element_alpha_hidden);
+
+    // Show 'B: Cancel' on both the loader and start screens
+    update_element_alpha(&all_element_alphas->icons.three_columns.centre_b_button, element_alpha_visible);
+
+    // Show 'Control Stick: Select' and 'A: Confirm' just on the loader menu
+    update_element_alpha(&all_element_alphas->icons.three_columns.left_control_stick, current_gameselect_state == SUBMENU_GAMESELECT_LOADER ? element_alpha_visible : element_alpha_hidden);
+    update_element_alpha(&all_element_alphas->icons.three_columns.right_a_button, current_gameselect_state == SUBMENU_GAMESELECT_LOADER ? element_alpha_visible : element_alpha_hidden);
+}
+
+static void update_pal_button_languages() {
+    if (!current_pal_buttons_language || !pal_button_language_elements) {
+        // Only PAL 1.0 and 1.2 have runtime-configurable languages; other versions don't need this additional step
+        return;
+    }
+
+    for (int i = 0; i < NUM_PAL_LANGUAGES; i++) {
+        element_alpha_update_state_t language_state = (i == *current_pal_buttons_language) ? element_alpha_visible : element_alpha_hidden;
+        update_element_alpha(&pal_button_language_elements[i], language_state);
+    }
+}
+
+__attribute_used__ void patch_update_button_alphas() {
+    bool ran_default_code = false;
+
+    switch (*cur_menu_id) {
+        case MENU_GAMESELECT_TRANSITION_ID:
+            update_gameplay_button_text();
+            update_gameplay_button_icons();
+            break;
+
+        default:
+            update_button_alphas();
+            ran_default_code = true;
+            break;
+    }
+
+    if (!ran_default_code) {
+        // If we didn't run the default code, we also have to take care of updating the per-language elements on PAL systems
+        update_pal_button_languages();
+    }
+}

patches/source/button_descriptions.h

@@ -0,0 +1,43 @@
+#include <gctypes.h>
+
+#include "element_alpha.h"
+
+typedef struct {
+    struct {
+        struct {
+            element_alpha_state_t left_control_stick;
+            element_alpha_state_t centre_b_button;
+            element_alpha_state_t right_a_button;
+        } three_columns;
+
+        struct {
+            element_alpha_state_t control_stick;
+        } one_column;
+
+        struct {
+            element_alpha_state_t left_b_button;
+            element_alpha_state_t right_a_button;
+        } two_columns;
+    } icons;
+
+    struct {
+        struct {
+            element_alpha_state_t menu_selection;
+        } one_column;
+
+        struct {
+            element_alpha_state_t left_cancel;
+            element_alpha_state_t right_confirm;
+        } two_columns;
+
+        struct {
+            element_alpha_state_t left_select;
+            element_alpha_state_t left_change;
+            element_alpha_state_t centre_cancel;
+            element_alpha_state_t centre_finish;
+            element_alpha_state_t right_confirm;
+        } three_columns;
+    } text;
+
+    // There are more elements past this point that relate to other elements, e.g. menus
+} all_element_alphas_t;

patches/source/element_alpha.c

@@ -0,0 +1,5 @@
+#include "element_alpha.h"
+
+#include "attr.h"
+
+__attribute_reloc__ void (*update_element_alpha)(element_alpha_state_t *element, element_alpha_update_state_t new_state);

patches/source/element_alpha.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <gctypes.h>
+
+typedef struct {
+    u16 current_alpha; // Ranges from 0 to (fade_duration + start_delay)
+    u16 fade_duration; // Frames; typically 0x14
+    u16 start_delay; // Frames; typically 0
+    u16 frame_counter; // Incremented with every update
+    u8 unk0;
+    u8 max_output;
+    u16 unknown_output_multiplier;
+    u32 unk1;
+} element_alpha_state_t;
+
+typedef enum {
+    element_alpha_visible,
+    element_alpha_hidden,
+    element_alpha_dimmed
+} element_alpha_update_state_t;
+
+extern void (*update_element_alpha)(element_alpha_state_t *element, element_alpha_update_state_t new_state);

patches/source/menu.h

@@ -1,3 +1,5 @@
+#include <gctypes.h>
+
 #define MENU_SELECTION_ID 0
 #define MENU_GAMESELECT_ID 1
 #define MENU_GAMESELECT_TRANSITION_ID 2
@@ -25,6 +27,8 @@
 #define SOUND_CARD_MOVE 0x0b
 #define SOUND_CARD_ERROR 0x0d
 
+extern u32 current_gameselect_state;
+
 extern int selected_slot;
 extern int top_line_num;
 

patches/source/patch.s

@@ -115,3 +115,6 @@ patch_inst_pal "_patch_menu_alpha_setup" 0x81312c3c 0x81312284 0x81312d7c bl pre
 patch_inst_pal "_fix_video_mode_init" 0x81300520 0x81300520 0x81300610 bl get_tvmode
 
 patch_inst_global "_patch_pre_main" 0x81300090 bl pre_main
+
+patch_inst_ntsc "_patch_update_button_alphas" 0x81312104 0x81312354 0x813126ec 0x81312704 bl patch_update_button_alphas
+patch_inst_pal "_patch_update_button_alphas" 0x81312c38 0x81312280 0x81312d78 bl patch_update_button_alphas