add screen layout system

5 files changed, 545 insertions, 46 deletions

diff --git a/src/frontend/FrontendUtil.h b/src/frontend/FrontendUtil.h
index 6a6f8ea..1fd7329 100644
--- a/src/frontend/FrontendUtil.h
+++ b/src/frontend/FrontendUtil.h
@@ -89,6 +89,32 @@ bool SaveState(const char* filename);
 void UndoStateLoad();
 
 
+// setup the display layout based on the provided display size and parameters
+// * screenWidth/screenHeight: size of the host display
+// * screenLayout: how the DS screens are laid out
+//     0 = natural (top screen above bottom screen always)
+//     1 = vertical
+//     2 = horizontal
+// * rotation: angle at which the DS screens are presented: 0/1/2/3 = 0/90/180/270
+// * sizing: how the display size is shared between the two screens
+//     0 = even (both screens get same size)
+//     1 = emphasize top screen (make top screen as big as possible, fit bottom screen in remaining space)
+//     2 = emphasize bottom screen
+// * screenGap: size of the gap between the two screens
+// * integerScale: force screens to be scaled up at integer scaling factors
+void SetupScreenLayout(int screenWidth, int screenHeight, int screenLayout, int rotation, int sizing, int screenGap, bool integerScale);
+
+// get a 2x3 transform matrix for the given screen (0=top, 1=bottom)
+// note: the transform assumes an origin point at the top left of the display,
+// X going left and Y going down
+// for each screen the source coordinates should be (0,0) and (256,192)
+float* GetScreenTransform(int screen);
+
+// de-transform the provided host display coordinates to get coordinates
+// on the bottom screen
+void GetTouchCoords(int& x, int& y);
+
+
 // initialize the audio utility
 void Init_Audio(int outputfreq);
 
diff --git a/src/frontend/Util_Video.cpp b/src/frontend/Util_Video.cpp
new file mode 100644
index 0000000..cd4e21c
--- /dev/null
+++ b/src/frontend/Util_Video.cpp
@@ -0,0 +1,334 @@
+/*
+    Copyright 2016-2020 Arisotura
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <cmath>
+#include <algorithm>
+
+#include "FrontendUtil.h"
+
+
+namespace Frontend
+{
+
+float TopScreenMtx[6];
+float BotScreenMtx[6];
+float TouchMtx[6];
+
+
+void M23_Identity(float* m)
+{
+    m[0] = 1; m[1] = 0;
+    m[2] = 0; m[3] = 1;
+    m[4] = 0; m[5] = 0;
+}
+
+void M23_Scale(float* m, float s)
+{
+    m[0] *= s; m[1] *= s;
+    m[2] *= s; m[3] *= s;
+    m[4] *= s; m[5] *= s;
+}
+
+void M23_RotateFast(float* m, int angle)
+{
+    if (angle == 0) return;
+
+    float temp[4]; memcpy(temp, m, sizeof(float)*4);
+
+    switch (angle)
+    {
+    case 1: // 90
+        m[0] = temp[2];
+        m[1] = temp[3];
+        m[2] = -temp[0];
+        m[3] = -temp[1];
+        break;
+
+    case 2: // 180
+        m[0] = -temp[0];
+        m[1] = -temp[1];
+        m[2] = -temp[2];
+        m[3] = -temp[3];
+        break;
+
+    case 3: // 270
+        m[0] = -temp[2];
+        m[1] = -temp[3];
+        m[2] = temp[0];
+        m[3] = temp[1];
+        break;
+    }
+}
+
+void M23_Translate(float* m, float tx, float ty)
+{
+    m[4] += tx;
+    m[5] += ty;
+}
+
+void M23_Multiply(float* m, float* _a, float* _b)
+{
+    float a[6]; memcpy(a, _a, 6*sizeof(float));
+    float b[6]; memcpy(b, _b, 6*sizeof(float));
+
+    m[0] = (a[0] * b[0]) + (a[2] * b[1]);
+    m[1] = (a[1] * b[0]) + (a[3] * b[1]);
+
+    m[2] = (a[0] * b[2]) + (a[2] * b[3]);
+    m[3] = (a[1] * b[2]) + (a[3] * b[3]);
+
+    m[4] = (a[0] * b[4]) + (a[2] * b[5]) + a[4];
+    m[5] = (a[1] * b[4]) + (a[3] * b[5]) + a[5];
+}
+
+void M23_Transform(float* m, float& x, float& y)
+{
+    float vx = x;
+    float vy = y;
+
+    x = (vx * m[0]) + (vy * m[2]) + m[4];
+    y = (vx * m[1]) + (vy * m[3]) + m[5];
+}
+
+
+void SetupScreenLayout(int screenWidth, int screenHeight, int screenLayout, int rotation, int sizing, int screenGap, bool integerScale)
+{
+    float refpoints[4][2] =
+    {
+        {0, 0}, {256, 192},
+        {0, 0}, {256, 192}
+    };
+
+    int layout = screenLayout == 0
+        ? ((rotation % 2 == 0) ? 0 : 1)
+        : screenLayout - 1;
+
+    float botScale = 1;
+    float botTrans[4] = {0};
+
+    M23_Identity(TopScreenMtx);
+    M23_Identity(BotScreenMtx);
+
+    M23_Translate(TopScreenMtx, -256/2, -192/2);
+    M23_Translate(BotScreenMtx, -256/2, -192/2);
+
+    // rotation
+    {
+        float rotmtx[6];
+        M23_Identity(rotmtx);
+
+        M23_RotateFast(rotmtx, rotation);
+        M23_Multiply(TopScreenMtx, rotmtx, TopScreenMtx);
+        M23_Multiply(BotScreenMtx, rotmtx, BotScreenMtx);
+
+        M23_Transform(TopScreenMtx, refpoints[0][0], refpoints[0][1]);
+        M23_Transform(TopScreenMtx, refpoints[1][0], refpoints[1][1]);
+        M23_Transform(BotScreenMtx, refpoints[2][0], refpoints[2][1]);
+        M23_Transform(BotScreenMtx, refpoints[3][0], refpoints[3][1]);
+    }
+
+    // move screens apart
+    {
+        int idx = layout == 0 ? 1 : 0;
+        float offset =
+            (((layout == 0 && (rotation % 2 == 0)) || (layout == 1 && (rotation % 2 == 1))
+                ? 192.f : 256.f)
+            + screenGap) / 2.f;
+        if (rotation == 1 || rotation == 2)
+            offset *= -1.f;
+
+        M23_Translate(TopScreenMtx, (idx==0)?-offset:0, (idx==1)?-offset:0);
+        M23_Translate(BotScreenMtx, (idx==0)?offset:0, (idx==1)?offset:0);
+
+        refpoints[0][idx] -= offset;
+        refpoints[1][idx] -= offset;
+        refpoints[2][idx] += offset;
+        refpoints[3][idx] += offset;
+
+        botTrans[idx] = offset;
+    }
+
+    // scale
+    {
+        if (sizing == 0)
+        {
+            float minX = refpoints[0][0], maxX = minX;
+            float minY = refpoints[0][1], maxY = minY;
+
+            for (int i = 1; i < 4; i++)
+            {
+                minX = std::min(minX, refpoints[i][0]);
+                minY = std::min(minY, refpoints[i][1]);
+                maxX = std::max(maxX, refpoints[i][0]);
+                maxY = std::max(maxY, refpoints[i][1]);
+            }
+
+            float hSize = maxX - minX;
+            float vSize = maxY - minY;
+
+            // scale evenly
+            float scale = std::min(screenWidth / hSize, screenHeight / vSize);
+
+            if (integerScale)
+                scale = floor(scale);
+
+            M23_Scale(TopScreenMtx, scale);
+            M23_Scale(BotScreenMtx, scale);
+
+            for (int i = 0; i < 4; i++)
+            {
+                refpoints[i][0] *= scale;
+                refpoints[i][1] *= scale;
+            }
+
+            botScale = scale;
+        }
+        else
+        {
+            int primOffset = (sizing == 1) ? 0 : 2;
+            int secOffset = (sizing == 1) ? 2 : 0;
+            float* primMtx = (sizing == 1) ? TopScreenMtx : BotScreenMtx;
+            float* secMtx = (sizing == 1) ? BotScreenMtx : TopScreenMtx;
+
+            float primMinX = refpoints[primOffset][0], primMaxX = primMinX;
+            float primMinY = refpoints[primOffset][1], primMaxY = primMinY;
+            float secMinX = refpoints[secOffset][0], secMaxX = secMinX;
+            float secMinY = refpoints[secOffset][1], secMaxY = secMinY;
+
+            primMinX = std::min(primMinX, refpoints[primOffset+1][0]);
+            primMinY = std::min(primMinY, refpoints[primOffset+1][1]);
+            primMaxX = std::max(primMaxX, refpoints[primOffset+1][0]);
+            primMaxY = std::max(primMaxY, refpoints[primOffset+1][1]);
+
+            secMinX = std::min(secMinX, refpoints[secOffset+1][0]);
+            secMinY = std::min(secMinY, refpoints[secOffset+1][1]);
+            secMaxX = std::max(secMaxX, refpoints[secOffset+1][0]);
+            secMaxY = std::max(secMaxY, refpoints[secOffset+1][1]);
+
+            float primHSize = layout == 1 ? std::max(primMaxX, -primMinX) : primMaxX - primMinX;
+            float primVSize = layout == 0 ? std::max(primMaxY, -primMinY) : primMaxY - primMinY;
+
+            float secHSize = layout == 1 ? std::max(secMaxX, -secMinX) : secMaxX - secMinX;
+            float secVSize = layout == 0 ? std::max(secMaxY, -secMinY) : secMaxY - secMinY;
+
+            float primScale = std::min(screenWidth / primHSize, screenHeight / primVSize);
+            float secScale = 1.f;
+
+            if (layout == 0)
+            {
+                if (screenHeight - primVSize * primScale < secVSize)
+                    primScale = std::min((screenWidth - secHSize) / primHSize, (screenHeight - secVSize) / primVSize);
+                else
+                    secScale = std::min((screenHeight - primVSize * primScale) / secVSize, screenWidth / secHSize);
+            }
+            else
+            {
+                if (screenWidth - primHSize * primScale < secHSize)
+                    primScale = std::min((screenWidth - secHSize) / primHSize, (screenHeight - secVSize) / primVSize);
+                else
+                    secScale = std::min((screenWidth - primHSize * primScale) / secHSize, screenHeight / secVSize);
+            }
+
+            if (integerScale)
+            {
+                primScale = floor(primScale);
+                secScale = floor(secScale);
+            }
+
+            M23_Scale(primMtx, primScale);
+            M23_Scale(secMtx, secScale);
+
+            refpoints[primOffset+0][0] *= primScale;
+            refpoints[primOffset+0][1] *= primScale;
+            refpoints[primOffset+1][0] *= primScale;
+            refpoints[primOffset+1][1] *= primScale;
+            refpoints[secOffset+0][0] *= secScale;
+            refpoints[secOffset+0][1] *= secScale;
+            refpoints[secOffset+1][0] *= secScale;
+            refpoints[secOffset+1][1] *= secScale;
+
+            botScale = (sizing == 1) ? secScale : primScale;
+        }
+    }
+
+    // position
+    {
+        float minX = refpoints[0][0], maxX = minX;
+        float minY = refpoints[0][1], maxY = minY;
+
+        for (int i = 1; i < 4; i++)
+        {
+            minX = std::min(minX, refpoints[i][0]);
+            minY = std::min(minY, refpoints[i][1]);
+            maxX = std::max(maxX, refpoints[i][0]);
+            maxY = std::max(maxY, refpoints[i][1]);
+        }
+
+        float width = maxX - minX;
+        float height = maxY - minY;
+
+        float tx = (screenWidth/2) - (width/2) - minX;
+        float ty = (screenHeight/2) - (height/2) - minY;
+
+        M23_Translate(TopScreenMtx, tx, ty);
+        M23_Translate(BotScreenMtx, tx, ty);
+
+        botTrans[2] = tx; botTrans[3] = ty;
+    }
+
+    // prepare a 'reverse' matrix for the touchscreen
+    // this matrix undoes the transforms applied to the bottom screen
+    // and can be used to calculate touchscreen coords from host screen coords
+    {
+        M23_Identity(TouchMtx);
+
+        M23_Translate(TouchMtx, -botTrans[2], -botTrans[3]);
+        M23_Scale(TouchMtx, 1.f / botScale);
+        M23_Translate(TouchMtx, -botTrans[0], -botTrans[1]);
+
+        float rotmtx[6];
+        M23_Identity(rotmtx);
+        M23_RotateFast(rotmtx, (4-rotation) & 3);
+        M23_Multiply(TouchMtx, rotmtx, TouchMtx);
+
+        M23_Translate(TouchMtx, 256/2, 192/2);
+    }
+}
+
+float* GetScreenTransform(int screen)
+{
+    if (screen == 0) return TopScreenMtx;
+    else             return BotScreenMtx;
+}
+
+void GetTouchCoords(int& x, int& y)
+{
+    float vx = x;
+    float vy = y;
+
+    M23_Transform(TouchMtx, vx, vy);
+
+    x = (int)vx;
+    y = (int)vy;
+}
+
+}
+
diff --git a/src/frontend/qt_sdl/CMakeLists.txt b/src/frontend/qt_sdl/CMakeLists.txt
index ffd7d17..7bc81f0 100644
--- a/src/frontend/qt_sdl/CMakeLists.txt
+++ b/src/frontend/qt_sdl/CMakeLists.txt
@@ -10,6 +10,7 @@ SET(SOURCES_QT_SDL
 	PlatformConfig.cpp
 	
 	../Util_ROM.cpp
+	../Util_Video.cpp
 	../Util_Audio.cpp
 	../FrontendUtil.h
 	../mic_blow.h
diff --git a/src/frontend/qt_sdl/main.cpp b/src/frontend/qt_sdl/main.cpp
index 245324f..0d10378 100644
--- a/src/frontend/qt_sdl/main.cpp
+++ b/src/frontend/qt_sdl/main.cpp
@@ -62,6 +62,8 @@ bool RunningSomething;
 MainWindow* mainWindow;
 EmuThread* emuThread;
 
+int autoScreenSizing = 0;
+
 SDL_AudioDeviceID audioDevice;
 int audioFreq;
 SDL_cond* audioSync;
@@ -250,16 +252,19 @@ EmuThread::EmuThread(QObject* parent) : QThread(parent)
     connect(this, SIGNAL(windowEmuStop()), mainWindow, SLOT(onEmuStop()));
     connect(this, SIGNAL(windowEmuPause()), mainWindow->actPause, SLOT(trigger()));
     connect(this, SIGNAL(windowEmuReset()), mainWindow->actReset, SLOT(trigger()));
+    connect(this, SIGNAL(screenLayoutChange()), mainWindow->panel, SLOT(onScreenLayoutChanged()));
 }
 
 void EmuThread::run()
 {
+    u32 mainScreenPos[3];
+
     NDS::Init();
 
-    /*MainScreenPos[0] = 0;
-    MainScreenPos[1] = 0;
-    MainScreenPos[2] = 0;
-    AutoScreenSizing = 0;*/
+    mainScreenPos[0] = 0;
+    mainScreenPos[1] = 0;
+    mainScreenPos[2] = 0;
+    autoScreenSizing = 0;
 
     /*if (Screen_UseGL)
     {
@@ -333,14 +338,14 @@ void EmuThread::run()
             }*/
 
             // auto screen layout
-            /*{
-                MainScreenPos[2] = MainScreenPos[1];
-                MainScreenPos[1] = MainScreenPos[0];
-                MainScreenPos[0] = NDS::PowerControl9 >> 15;
+            {
+                mainScreenPos[2] = mainScreenPos[1];
+                mainScreenPos[1] = mainScreenPos[0];
+                mainScreenPos[0] = NDS::PowerControl9 >> 15;
 
                 int guess;
-                if (MainScreenPos[0] == MainScreenPos[2] &&
-                    MainScreenPos[0] != MainScreenPos[1])
+                if (mainScreenPos[0] == mainScreenPos[2] &&
+                    mainScreenPos[0] != mainScreenPos[1])
                 {
                     // constant flickering, likely displaying 3D on both screens
                     // TODO: when both screens are used for 2D only...???
@@ -348,18 +353,18 @@ void EmuThread::run()
                 }
                 else
                 {
-                    if (MainScreenPos[0] == 1)
+                    if (mainScreenPos[0] == 1)
                         guess = 1;
                     else
                         guess = 2;
                 }
 
-                if (guess != AutoScreenSizing)
+                if (guess != autoScreenSizing)
                 {
-                    AutoScreenSizing = guess;
-                    SetupScreenRects(WindowWidth, WindowHeight);
+                    autoScreenSizing = guess;
+                    emit screenLayoutChange();
                 }
-            }*/
+            }
 
             // emulate
             u32 nlines = NDS::RunFrame();
@@ -540,6 +545,9 @@ MainWindowPanel::MainWindowPanel(QWidget* parent) : QWidget(parent)
     screen[0] = new QImage(256, 192, QImage::Format_RGB32);
     screen[1] = new QImage(256, 192, QImage::Format_RGB32);
 
+    screenTrans[0].reset();
+    screenTrans[1].reset();
+
     touching = false;
 }
 
@@ -549,6 +557,64 @@ MainWindowPanel::~MainWindowPanel()
     delete screen[1];
 }
 
+void MainWindowPanel::ensureProperMinSize()
+{
+    bool isHori = (Config::ScreenRotation == 1 || Config::ScreenRotation == 3);
+    int gap = Config::ScreenGap;
+
+    int w = 256;
+    int h = 192;
+
+    if (Config::ScreenLayout == 0) // natural
+    {
+        if (isHori)
+            setMinimumSize(h+gap+h, w);
+        else
+            setMinimumSize(w, h+gap+h);
+    }
+    else if (Config::ScreenLayout == 1) // vertical
+    {
+        if (isHori)
+            setMinimumSize(h, w+gap+w);
+        else
+            setMinimumSize(w, h+gap+h);
+    }
+    else // horizontal
+    {
+        if (isHori)
+            setMinimumSize(h+gap+h, w);
+        else
+            setMinimumSize(w+gap+w, h);
+    }
+}
+
+void MainWindowPanel::setupScreenLayout()
+{
+    int w = width();
+    int h = height();
+    float* mtx;
+
+    int sizing = Config::ScreenSizing;
+    if (sizing == 3) sizing = autoScreenSizing;
+
+    Frontend::SetupScreenLayout(w, h,
+                                Config::ScreenLayout,
+                                Config::ScreenRotation,
+                                sizing,
+                                Config::ScreenGap,
+                                Config::IntegerScaling != 0);
+
+    mtx = Frontend::GetScreenTransform(0);
+    screenTrans[0].setMatrix(mtx[0], mtx[1], 0.f,
+                             mtx[2], mtx[3], 0.f,
+                             mtx[4], mtx[5], 1.f);
+
+    mtx = Frontend::GetScreenTransform(1);
+    screenTrans[1].setMatrix(mtx[0], mtx[1], 0.f,
+                             mtx[2], mtx[3], 0.f,
+                             mtx[4], mtx[5], 1.f);
+}
+
 void MainWindowPanel::paintEvent(QPaintEvent* event)
 {
     QPainter painter(this);
@@ -562,27 +628,18 @@ void MainWindowPanel::paintEvent(QPaintEvent* event)
     memcpy(screen[0]->scanLine(0), GPU::Framebuffer[frontbuf][0], 256*192*4);
     memcpy(screen[1]->scanLine(0), GPU::Framebuffer[frontbuf][1], 256*192*4);
 
-    QRect src = QRect(0, 0, 256, 192);
+    QRect screenrc = QRect(0, 0, 256, 192);
 
-    QRect dstTop = QRect(0, 0, 256, 192); // TODO
-    QRect dstBot = QRect(0, 192, 256, 192); // TODO
+    painter.setTransform(screenTrans[0]);
+    painter.drawImage(screenrc, *screen[0]);
 
-    painter.drawImage(dstTop, *screen[0]);
-    painter.drawImage(dstBot, *screen[1]);
+    painter.setTransform(screenTrans[1]);
+    painter.drawImage(screenrc, *screen[1]);
 }
 
-
-void MainWindowPanel::transformTSCoords(int& x, int& y)
+void MainWindowPanel::resizeEvent(QResizeEvent* event)
 {
-    // TODO: actual screen de-transform taking screen layout/rotation/etc into account
-
-    y -= 192;
-
-    // clamp to screen range
-    if (x < 0) x = 0;
-    else if (x > 255) x = 255;
-    if (y < 0) y = 0;
-    else if (y > 191) y = 191;
+    setupScreenLayout();
 }
 
 void MainWindowPanel::mousePressEvent(QMouseEvent* event)
@@ -593,11 +650,11 @@ void MainWindowPanel::mousePressEvent(QMouseEvent* event)
     int x = event->pos().x();
     int y = event->pos().y();
 
-    if (x >= 0 && x < 256 && y >= 192 && y < 384)
+    Frontend::GetTouchCoords(x, y);
+
+    if (x >= 0 && x < 256 && y >= 0 && y < 192)
     {
         touching = true;
-
-        transformTSCoords(x, y);
         NDS::TouchScreen(x, y);
     }
 }
@@ -623,10 +680,22 @@ void MainWindowPanel::mouseMoveEvent(QMouseEvent* event)
     int x = event->pos().x();
     int y = event->pos().y();
 
-    transformTSCoords(x, y);
+    Frontend::GetTouchCoords(x, y);
+
+    // clamp to screen range
+    if (x < 0) x = 0;
+    else if (x > 255) x = 255;
+    if (y < 0) y = 0;
+    else if (y > 191) y = 191;
+
     NDS::TouchScreen(x, y);
 }
 
+void MainWindowPanel::onScreenLayoutChanged()
+{
+    setupScreenLayout();
+}
+
 
 MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
 {
@@ -750,7 +819,7 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
                 int data = i*90;
                 actScreenRotation[i] = submenu->addAction(QString("%1°").arg(data));
                 actScreenRotation[i]->setActionGroup(grpScreenRotation);
-                actScreenRotation[i]->setData(QVariant(data));
+                actScreenRotation[i]->setData(QVariant(i));
                 actScreenRotation[i]->setCheckable(true);
             }
 
@@ -834,8 +903,9 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
 
     panel = new MainWindowPanel(this);
     setCentralWidget(panel);
-    panel->setMinimumSize(256, 384);
+    panel->ensureProperMinSize();
 
+    resize(Config::WindowWidth, Config::WindowHeight);
 
     for (int i = 0; i < 9; i++)
     {
@@ -877,6 +947,16 @@ MainWindow::~MainWindow()
 {
 }
 
+void MainWindow::resizeEvent(QResizeEvent* event)
+{
+    int w = event->size().width();
+    int h = event->size().height();
+
+    Config::WindowWidth = w;
+    Config::WindowHeight = h;
+
+    // TODO: detect when the window gets maximized!
+}
 
 void MainWindow::keyPressEvent(QKeyEvent* event)
 {
@@ -1264,32 +1344,79 @@ void MainWindow::onChangeSavestateSRAMReloc(bool checked)
 
 void MainWindow::onChangeScreenSize()
 {
-    //
+    int factor = ((QAction*)sender())->data().toInt();
+
+    bool isHori = (Config::ScreenRotation == 1 || Config::ScreenRotation == 3);
+    int gap = Config::ScreenGap;
+
+    int w = 256*factor;
+    int h = 192*factor;
+
+    QSize diff = size() - panel->size();
+
+    if (Config::ScreenLayout == 0) // natural
+    {
+        if (isHori)
+            resize(QSize(h+gap+h, w) + diff);
+        else
+            resize(QSize(w, h+gap+h) + diff);
+    }
+    else if (Config::ScreenLayout == 1) // vertical
+    {
+        if (isHori)
+            resize(QSize(h, w+gap+w) + diff);
+        else
+            resize(QSize(w, h+gap+h) + diff);
+    }
+    else // horizontal
+    {
+        if (isHori)
+            resize(QSize(h+gap+h, w) + diff);
+        else
+            resize(QSize(w+gap+w, h) + diff);
+    }
 }
 
 void MainWindow::onChangeScreenRotation(QAction* act)
 {
-    //
+    int rot = act->data().toInt();
+    Config::ScreenRotation = rot;
+
+    panel->ensureProperMinSize();
+    panel->setupScreenLayout();
 }
 
 void MainWindow::onChangeScreenGap(QAction* act)
 {
-    //
+    int gap = act->data().toInt();
+    Config::ScreenGap = gap;
+
+    panel->ensureProperMinSize();
+    panel->setupScreenLayout();
 }
 
 void MainWindow::onChangeScreenLayout(QAction* act)
 {
-    //
+    int layout = act->data().toInt();
+    Config::ScreenLayout = layout;
+
+    panel->ensureProperMinSize();
+    panel->setupScreenLayout();
 }
 
 void MainWindow::onChangeScreenSizing(QAction* act)
 {
-    //
+    int sizing = act->data().toInt();
+    Config::ScreenSizing = sizing;
+
+    panel->setupScreenLayout();
 }
 
 void MainWindow::onChangeIntegerScaling(bool checked)
 {
-    //
+    Config::IntegerScaling = checked?1:0;
+
+    panel->setupScreenLayout();
 }
 
 void MainWindow::onChangeScreenFiltering(bool checked)
diff --git a/src/frontend/qt_sdl/main.h b/src/frontend/qt_sdl/main.h
index 7051a08..2d14eea 100644
--- a/src/frontend/qt_sdl/main.h
+++ b/src/frontend/qt_sdl/main.h
@@ -54,6 +54,8 @@ signals:
 
     void windowLimitFPSChange();
 
+    void screenLayoutChange();
+
 private:
     volatile int EmuStatus;
     int PrevEmuStatus;
@@ -69,18 +71,25 @@ public:
     explicit MainWindowPanel(QWidget* parent);
     ~MainWindowPanel();
 
+    void ensureProperMinSize();
+    void setupScreenLayout();
+
 protected:
     void paintEvent(QPaintEvent* event) override;
 
+    void resizeEvent(QResizeEvent* event) override;
+
     void mousePressEvent(QMouseEvent* event) override;
     void mouseReleaseEvent(QMouseEvent* event) override;
     void mouseMoveEvent(QMouseEvent* event) override;
 
+private slots:
+    void onScreenLayoutChanged();
+
 private:
     QImage* screen[2];
+    QTransform screenTrans[2];
     bool touching;
-
-    void transformTSCoords(int& x, int& y);
 };
 
 
@@ -93,6 +102,8 @@ public:
     ~MainWindow();
 
 protected:
+    void resizeEvent(QResizeEvent* event) override;
+
     void keyPressEvent(QKeyEvent* event) override;
     void keyReleaseEvent(QKeyEvent* event) override;
 
@@ -138,9 +149,9 @@ private slots:
 private:
     QString loadErrorStr(int error);
 
+public:
     MainWindowPanel* panel;
 
-public:
     QAction* actOpenROM;
     QAction* actBootFirmware;
     QAction* actSaveState[9];