1 files changed, 334 insertions, 0 deletions
diff --git a/src/frontend/Util_Video.cpp b/src/frontend/Util_Video.cpp
new file mode 100644
index 0000000..87cb9b5
--- /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 / 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 / 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);
+    }
+}
+
+void GetScreenTransforms(float* top, float* bot)
+{
+    memcpy(top, TopScreenMtx, 6*sizeof(float));
+    memcpy(bot, BotScreenMtx, 6*sizeof(float));
+}
+
+void GetTouchCoords(int& x, int& y)
+{
+    float vx = x;
+    float vy = y;
+
+    M23_Transform(TouchMtx, vx, vy);
+
+    x = (int)vx;
+    y = (int)vy;
+}
+
+}
+