Added some test code in Core that allow for pinch zooming and two-finger rotation.

src/Core.cpp

@@ -202,13 +202,29 @@ void Core::doProcess() {
           r_view->setView(v_width, v_height);
         }
       }
+    } else if (event.type == SDL_MULTIGESTURE) {
+      LOG(LOG_INFO) << "gesture: " << event.mgesture.x << "x" << event.mgesture.y << ", rot:" << event.mgesture.dTheta << ", pinch:" << event.mgesture.dDist << ", fingers:" << event.mgesture.numFingers;
+      RenderCamera *camera = scene->getCamera(1);
+      Vec3 camera_pos = camera->getPosition();
+      camera_pos.y -= event.mgesture.dDist*256.0f;
+      camera->setPosition(camera_pos.x, camera_pos.y, camera_pos.z);
+      float yaw = camera->getYaw();
+      camera->setYaw(yaw - (event.mgesture.dTheta*128.0f));
+      camera->doRefresh();
     } else if (event.type == SDL_FINGERMOTION) {
-      LOG(LOG_INFO) << "finger: " << event.tfinger.pressure << " " << event.tfinger.x << "x" << event.tfinger.y << " " << event.tfinger.dx << "x" << event.tfinger.dy;
+      LOG(LOG_INFO) << "finger: " << event.tfinger.fingerId << " " << event.tfinger.x << "x" << event.tfinger.y << " " << event.tfinger.dx << "x" << event.tfinger.dy;
+
       RenderCamera *camera = scene->getCamera(1);
       Vec3 camera_pos = camera->getPosition();
       float x = event.tfinger.dx * v_width/16;
       float y = event.tfinger.dy * v_height/16;
-      camera->setPosition(camera_pos.x-x, camera_pos.y, camera_pos.z+y);
+
+      // This is weird.
+      float yaw = camera->getYaw() * M_PI / 180.0f;
+      float ax = (-x * cosf(yaw)) + (y * sinf(yaw));
+      float ay = (y * cosf(yaw)) - (-x * sinf(yaw));
+
+      camera->setPosition(camera_pos.x+ax, camera_pos.y, camera_pos.z+ay);
       camera->doRefresh();
     } else if (event.type == SDL_MOUSEMOTION) {
       if (event.motion.which == SDL_TOUCH_MOUSEID) continue;

src/RenderCamera.cpp

@@ -104,6 +104,15 @@ RenderView* RenderCamera::getRenderView() {
 Vec3 RenderCamera::getPosition() {
   return position;
 }
+float RenderCamera::getYaw() {
+  return yaw;
+}
+float RenderCamera::getPitch() {
+  return pitch;
+}
 float RenderCamera::getSize() {
   return size;
 }
+Mat4 RenderCamera::getModelview() {
+  return mv_matrix;
+}

src/RenderCamera.hpp

@@ -29,9 +29,12 @@ class RenderCamera {
     void setMode(int mode);
     Vec3 getPosition();
     void setPosition(float x, float y, float z);
+    float getPitch();
     void setPitch(float pitch);
+    float getYaw();
     void setYaw(float yaw);
     float getSize();
+    Mat4 getModelview();
   private:
     int render_mode;          // 0 = perspective, 1 = orthogonal
     Vec3 position;            // The camera's coordinates in 3D space