From ac83725f54c5f8e4754dc68815ca6333b885a66a Mon Sep 17 00:00:00 2001 From: danprice142 Date: Mon, 4 May 2026 21:43:44 +0100 Subject: [PATCH] Add multi-screen support with extended video callback Introduce multi-screen capability and an extended video refresh callback so the core can stream an auxiliary (bottom) screen to the frontend. Adds environment commands RETRO_ENVIRONMENT_SET_MULTI_SCREEN_AVAILABILITY and RETRO_ENVIRONMENT_GET_MULTI_SCREEN_ACTIVE, types retro_video_refresh_ext_t, retro_multi_screen_info, retro_multi_screen_query, and retro_set_video_refresh_ext. Implements an option (melonds_aux_stream_bottom_screen) to enable streaming of the bottom screen, updates geometry and screen layout handling when enabled, and emits the auxiliary framebuffer via the new callback when active. Changes touch headers, core options, state, and rendering logic to support this behavior and to notify the frontend of available screens during load_game. --- .../libretro-common/include/libretro.h | 48 +++++++++++++ src/libretro/libretro.cpp | 71 +++++++++++++++---- src/libretro/libretro_core_options.h | 14 ++++ src/libretro/libretro_state.h | 1 + 4 files changed, 122 insertions(+), 12 deletions(-) diff --git a/src/libretro/libretro-common/include/libretro.h b/src/libretro/libretro-common/include/libretro.h index bb114aed35..1096c7545f 100644 --- a/src/libretro/libretro-common/include/libretro.h +++ b/src/libretro/libretro-common/include/libretro.h @@ -1765,6 +1765,19 @@ enum retro_mod * (see enum retro_savestate_context) */ +#define RETRO_ENVIRONMENT_SET_MULTI_SCREEN_AVAILABILITY 82 + /* const struct retro_multi_screen_info * -- + * Tells the frontend how many screens this core can provide and + * their dimensions. Must be called in retro_load_game() before + * any retro_video_refresh_ext calls are made. + */ + +#define RETRO_ENVIRONMENT_GET_MULTI_SCREEN_ACTIVE 83 + /* struct retro_multi_screen_query * -- + * Allows the core to query which auxiliary screens the frontend + * actually wants rendered. screen_id 0 is always the main display. + */ + /* VFS functionality */ /* File paths: @@ -3800,6 +3813,40 @@ typedef bool (RETRO_CALLCONV *retro_environment_t)(unsigned cmd, void *data); typedef void (RETRO_CALLCONV *retro_video_refresh_t)(const void *data, unsigned width, unsigned height, size_t pitch); +/** + * Extended video refresh callback for multi-screen cores. + * @param data Framebuffer data. + * @param width Width of the framebuffer. + * @param height Height of the framebuffer. + * @param pitch Pitch of the framebuffer. + * @param screen_id Screen identifier (0 = main display, 1+ = auxiliary). + * @see RETRO_ENVIRONMENT_SET_MULTI_SCREEN_AVAILABILITY + * @see retro_set_video_refresh_ext + */ +typedef void (RETRO_CALLCONV *retro_video_refresh_ext_t)(const void *data, unsigned width, + unsigned height, size_t pitch, unsigned screen_id); + +/** + * Multi-screen capability info passed to RETRO_ENVIRONMENT_SET_MULTI_SCREEN_AVAILABILITY. + * Core declares how many screens it supports and their properties. + */ +struct retro_multi_screen_info +{ + unsigned num_screens; /* Total screens available (e.g., 2 for DS) */ + unsigned screen_width; /* Width of each screen (assumed same for all) */ + unsigned screen_height; /* Height of each screen (assumed same for all) */ +}; + +/** + * Query for RETRO_ENVIRONMENT_GET_MULTI_SCREEN_ACTIVE. + * Frontend tells core which screens are currently active. + */ +struct retro_multi_screen_query +{ + unsigned num_active_screens; /* How many screens frontend wants */ + unsigned active_screen_ids[4]; /* Which screen IDs to render (0=main, 1=aux1, etc.) */ +}; + /* Renders a single audio frame. Should only be used if implementation * generates a single sample at a time. * Format is signed 16-bit native endian. @@ -3835,6 +3882,7 @@ typedef int16_t (RETRO_CALLCONV *retro_input_state_t)(unsigned port, unsigned de * before the first call to retro_run() is made. */ RETRO_API void retro_set_environment(retro_environment_t); RETRO_API void retro_set_video_refresh(retro_video_refresh_t); +RETRO_API void retro_set_video_refresh_ext(retro_video_refresh_ext_t); RETRO_API void retro_set_audio_sample(retro_audio_sample_t); RETRO_API void retro_set_audio_sample_batch(retro_audio_sample_batch_t); RETRO_API void retro_set_input_poll(retro_input_poll_t); diff --git a/src/libretro/libretro.cpp b/src/libretro/libretro.cpp index 2207849bfa..fedb1d816c 100644 --- a/src/libretro/libretro.cpp +++ b/src/libretro/libretro.cpp @@ -35,6 +35,9 @@ retro_input_poll_t input_poll_cb; retro_input_state_t input_state_cb; retro_log_printf_t log_cb; retro_video_refresh_t video_cb; +retro_video_refresh_ext_t video_cb_ext = NULL; + +bool aux_stream_bottom_screen = false; std::string save_path; @@ -124,11 +127,23 @@ void retro_get_system_av_info(struct retro_system_av_info *info) { info->timing.fps = 32.0f * 1024.0f * 1024.0f / 560190.0f; info->timing.sample_rate = 32.0f * 1024.0f; - info->geometry.base_width = screen_layout_data.buffer_width; - info->geometry.base_height = screen_layout_data.buffer_height; - info->geometry.max_width = screen_layout_data.buffer_width; - info->geometry.max_height = screen_layout_data.buffer_height; - info->geometry.aspect_ratio = (float)screen_layout_data.buffer_width / (float)screen_layout_data.buffer_height; + + if (aux_stream_bottom_screen) + { + info->geometry.base_width = screen_layout_data.screen_width; + info->geometry.base_height = screen_layout_data.screen_height; + info->geometry.max_width = screen_layout_data.screen_width; + info->geometry.max_height = screen_layout_data.screen_height; + info->geometry.aspect_ratio = (float)screen_layout_data.screen_width / (float)screen_layout_data.screen_height; + } + else + { + info->geometry.base_width = screen_layout_data.buffer_width; + info->geometry.base_height = screen_layout_data.buffer_height; + info->geometry.max_width = screen_layout_data.buffer_width; + info->geometry.max_height = screen_layout_data.buffer_height; + info->geometry.aspect_ratio = (float)screen_layout_data.buffer_width / (float)screen_layout_data.buffer_height; + } } static bool update_option_visibility(void) @@ -311,6 +326,11 @@ void retro_set_video_refresh(retro_video_refresh_t cb) video_cb = cb; } +RETRO_API void retro_set_video_refresh_ext(retro_video_refresh_ext_t cb) +{ + video_cb_ext = cb; +} + void retro_set_controller_port_device(unsigned port, unsigned device) { log_cb(RETRO_LOG_INFO, "Plugging device %u into port %u.\n", device, port); @@ -370,6 +390,15 @@ static void check_variables(bool init) layout = ScreenLayout::HybridBottom; } + var.key = "melonds_aux_stream_bottom_screen"; + if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) + aux_stream_bottom_screen = !strcmp(var.value, "enabled"); + else + aux_stream_bottom_screen = false; + + if (aux_stream_bottom_screen) + layout = ScreenLayout::TopOnly; + var.key = "melonds_screen_gap"; if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) { @@ -616,7 +645,7 @@ static void check_variables(bool init) input_state.current_touch_mode = new_touch_mode; - update_screenlayout(layout, &screen_layout_data, enable_opengl, swapped_screens); + update_screenlayout(layout, &screen_layout_data, enable_opengl, aux_stream_bottom_screen ? false : swapped_screens); update_option_visibility(); } @@ -659,12 +688,13 @@ static void render_frame(void) #ifdef HAVE_OPENGL if(using_opengl) { + log_cb(RETRO_LOG_INFO, "[melonDS] Using OpenGL rendering\n"); if (current_renderer == CurrentRenderer::Software) render_opengl_frame(true); else render_opengl_frame(false); } - else if(!enable_opengl) + else +#endif { - #endif int frontbuf = GPU::FrontBuffer; if(screen_layout_data.hybrid) @@ -703,9 +733,16 @@ static void render_frame(void) video_cb((uint8_t*)screen_layout_data.buffer_ptr, screen_layout_data.buffer_width, screen_layout_data.buffer_height, screen_layout_data.buffer_width * sizeof(uint32_t)); } -#ifdef HAVE_OPENGL } -#endif + + if (aux_stream_bottom_screen && screen_layout_data.enable_top_screen) + { + int frontbuf = GPU::FrontBuffer; + unsigned pitch = VIDEO_WIDTH * sizeof(uint32_t); + + if (video_cb_ext) + video_cb_ext((uint8_t*)GPU::Framebuffer[frontbuf][1], VIDEO_WIDTH, VIDEO_HEIGHT, pitch, 1); + } } void retro_run(void) @@ -719,7 +756,7 @@ void retro_run(void) if (swapped_screens == false) { swap_screen_toggled = !swap_screen_toggled; - update_screenlayout(current_screen_layout, &screen_layout_data, enable_opengl, swap_screen_toggled); + update_screenlayout(current_screen_layout, &screen_layout_data, enable_opengl, aux_stream_bottom_screen ? false : swap_screen_toggled); refresh_opengl = true; } @@ -728,7 +765,7 @@ void retro_run(void) else { swapped_screens = input_state.swap_screens_btn; - update_screenlayout(current_screen_layout, &screen_layout_data, enable_opengl, swapped_screens); + update_screenlayout(current_screen_layout, &screen_layout_data, enable_opengl, aux_stream_bottom_screen ? false : swapped_screens); refresh_opengl = true; } } @@ -875,6 +912,16 @@ static bool _handle_load_game(unsigned type, const struct retro_game_info *info) check_variables(true); + if (aux_stream_bottom_screen) + { + struct retro_multi_screen_info info = { + 2, + screen_layout_data.screen_width, + screen_layout_data.screen_height + }; + environ_cb(RETRO_ENVIRONMENT_SET_MULTI_SCREEN_AVAILABILITY, &info); + } + // Initialize the opengl state if needed #ifdef HAVE_OPENGL if (enable_opengl) diff --git a/src/libretro/libretro_core_options.h b/src/libretro/libretro_core_options.h index e50715cd8c..20cd8f55bd 100644 --- a/src/libretro/libretro_core_options.h +++ b/src/libretro/libretro_core_options.h @@ -344,6 +344,20 @@ struct retro_core_option_v2_definition option_defs_us[] = { }, "Top/Bottom" }, + { + "melonds_aux_stream_bottom_screen", + "Stream Bottom Screen to Auxiliary Display", + NULL, + "Stream bottom screen to auxiliary display via extended callback.", + NULL, + "screen", + { + { "disabled", NULL }, + { "enabled", NULL }, + { NULL, NULL }, + }, + "disabled" + }, { "melonds_screen_gap", "Screen Gap", diff --git a/src/libretro/libretro_state.h b/src/libretro/libretro_state.h index 2103cc84f6..4196e12ef9 100644 --- a/src/libretro/libretro_state.h +++ b/src/libretro/libretro_state.h @@ -14,5 +14,6 @@ extern retro_input_poll_t input_poll_cb; extern retro_input_state_t input_state_cb; extern retro_log_printf_t log_cb; extern retro_video_refresh_t video_cb; +extern retro_video_refresh_ext_t video_cb_ext; #endif