From c1a44d38a0bd9e0c8728ade16be188b2bc9da673 Mon Sep 17 00:00:00 2001 From: Stefan Date: Wed, 6 Jul 2016 21:53:43 +0200 Subject: [PATCH] Use dispmanx scaling (#1) * Use dispmanx scaling * There is the new SDL hint SDL_VIDEO_RPI_SCALE_MODE. There are three values. * The variable can be set to the following values: * "0" - Window resolution is desktop resolution. * This is the behaviour of SDL <= 2.0.4. (default) * "1" - Requested video resolution will be scaled to desktop resolution. * Aspect ratio of requested video resolution will be respected. * "2" - Requested video resolution will be scaled to desktop resolution. * Add aspect ratio hint --- include/SDL_hints.h | 23 ++++++++++ src/video/raspberry/SDL_rpivideo.c | 67 ++++++++++++++++++++++++++---- 2 files changed, 81 insertions(+), 9 deletions(-) diff --git a/include/SDL_hints.h b/include/SDL_hints.h index 3bd5435fb..d245243f7 100644 --- a/include/SDL_hints.h +++ b/include/SDL_hints.h @@ -621,6 +621,29 @@ extern "C" { */ #define SDL_HINT_NO_SIGNAL_HANDLERS "SDL_NO_SIGNAL_HANDLERS" +/** + * \brief Tell dispmanx to stretch the SDL window to fill the display. + * + * This hint only applies to the rpi video driver. + * + * The variable can be set to the following values: + * "0" - Window resolution is desktop resolution. + * This is the behaviour of SDL <= 2.0.4. (default) + * "1" - Requested video resolution will be scaled to desktop resolution. + * Aspect ratio of requested video resolution will be respected. + * "2" - Requested video resolution will be scaled to desktop resolution. + */ +#define SDL_HINT_VIDEO_RPI_SCALE_MODE "SDL_VIDEO_RPI_SCALE_MODE" + +/** + * \brief Tell dispmanx to set an specific aspect ratio. + * + * This hint only applies to the rpi video driver. + * + * Must be set together with SDL_HINT_VIDEO_RPI_SCALE_MODE=1. + */ +#define SDL_HINT_VIDEO_RPI_RATIO "SDL_VIDEO_RPI_RATIO" + /** * \brief Tell SDL not to generate window-close events for Alt+F4 on Windows. * diff --git a/src/video/raspberry/SDL_rpivideo.c b/src/video/raspberry/SDL_rpivideo.c index 539c88c9b..1886674bb 100644 --- a/src/video/raspberry/SDL_rpivideo.c +++ b/src/video/raspberry/SDL_rpivideo.c @@ -31,6 +31,7 @@ */ /* SDL internals */ +#include "SDL_hints.h" #include "../SDL_sysvideo.h" #include "SDL_version.h" #include "SDL_syswm.h" @@ -214,6 +215,9 @@ RPI_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode) int RPI_CreateWindow(_THIS, SDL_Window * window) { + const char *hintScale = SDL_GetHint(SDL_HINT_VIDEO_RPI_SCALE_MODE); + const char *hintRatio = SDL_GetHint(SDL_HINT_VIDEO_RPI_RATIO); + char scalemode = '0'; SDL_WindowData *wdata; SDL_VideoDisplay *display; SDL_DisplayData *displaydata; @@ -235,23 +239,68 @@ RPI_CreateWindow(_THIS, SDL_Window * window) display = SDL_GetDisplayForWindow(window); displaydata = (SDL_DisplayData *) display->driverdata; - /* Windows have one size for now */ - window->w = display->desktop_mode.w; - window->h = display->desktop_mode.h; + float srcAspect = 1; + float dstAspect = 1; - /* OpenGL ES is the law here, buddy */ - window->flags |= SDL_WINDOW_OPENGL; + if (hintScale != NULL) + scalemode = *hintScale; /* Create a dispman element and associate a window to it */ - dst_rect.x = 0; - dst_rect.y = 0; - dst_rect.width = window->w; - dst_rect.height = window->h; + switch(scalemode) { + case '1': + /* Fullscreen mode. */ + /* Calculate source and destination aspect ratios. */ + if (hintRatio != NULL) + srcAspect = strtof(hintRatio, NULL); + else + srcAspect = (float)window->w / (float)window->h; + /* only allow sensible aspect ratios */ + if (srcAspect < 0.2f || srcAspect > 6.0f) + srcAspect = (float)window->w / (float)window->h; + dstAspect = (float)display->desktop_mode.w / (float)display->desktop_mode.h; + /* If source and destination aspect ratios are not equal correct destination width. */ + if (srcAspect < dstAspect) { + dst_rect.width = (unsigned)(display->desktop_mode.h * srcAspect); + dst_rect.height = display->desktop_mode.h; + } + else if (srcAspect > dstAspect) { + dst_rect.width = display->desktop_mode.w; + dst_rect.height = (unsigned)((float)display->desktop_mode.w / srcAspect); + } + else { + dst_rect.width = display->desktop_mode.w; + dst_rect.height = display->desktop_mode.h; + } + /* Center window. */ + dst_rect.x = (display->desktop_mode.w - dst_rect.width) / 2; + dst_rect.y = (display->desktop_mode.h - dst_rect.height) / 2; + break; + case '2': + /* Fullscreen streched mode. */ + dst_rect.x = 0; + dst_rect.y = 0; + dst_rect.width = display->desktop_mode.w; + dst_rect.height = display->desktop_mode.h; + break; + default: + /* Default mode. */ + window->w = display->desktop_mode.w; + window->h = display->desktop_mode.h; + + dst_rect.x = 0; + dst_rect.y = 0; + dst_rect.width = window->w; + dst_rect.height = window->h; + break; + } src_rect.x = 0; src_rect.y = 0; src_rect.width = window->w << 16; src_rect.height = window->h << 16; + + /* OpenGL ES is the law here, buddy */ + window->flags |= SDL_WINDOW_OPENGL; dispman_update = vc_dispmanx_update_start( 0 ); wdata->dispman_window.element = vc_dispmanx_element_add ( dispman_update, displaydata->dispman_display, SDL_RPI_VIDEOLAYER /* layer */, &dst_rect, 0/*src*/, &src_rect, DISPMANX_PROTECTION_NONE, &dispman_alpha /*alpha*/, 0/*clamp*/, 0/*transform*/);