Added g_PointerPositionLast

Improved delay calculation for parallax (should prevent backgrounds from flickering with big delays)
Fixed g_TexelSize having the wrong value and g_TexelSizeHalf not being defined

Signed-off-by: Alexis Maiquez <almamu@almamu.com>

main.cpp

@@ -23,6 +23,7 @@
 #include "WallpaperEngine/Assets/CPackageLoadException.h"
 
 float g_Time;
+float g_TimeLast;
 bool g_KeepRunning = true;
 int g_AudioVolume = 15;
 
@@ -84,7 +85,7 @@ int validatePath(const char* path, std::string& final)
     char finalPath [PATH_MAX];
     char* pointer = realpath (path, finalPath);
 
-    if (finalPath == nullptr)
+    if (pointer == nullptr)
         return errno;
 
     // ensure the path points to a folder
@@ -631,6 +632,8 @@ int main (int argc, char* argv[])
         glfwGetFramebufferSize (window, &windowWidth, &windowHeight);
         // set the default viewport
         context->setDefaultViewport ({0, 0, windowWidth, windowHeight});
+        // keep track of the previous frame's time
+        g_TimeLast = g_Time;
         // calculate the current time value
         g_Time = (float) glfwGetTime ();
         // get the start time of the frame

src/WallpaperEngine/Render/CScene.cpp

@@ -6,6 +6,9 @@
 
 #include "CScene.h"
 
+extern float g_Time;
+extern float g_TimeLast;
+
 using namespace WallpaperEngine;
 using namespace WallpaperEngine::Render;
 
@@ -239,10 +242,9 @@ void CScene::renderFrame (glm::ivec4 viewport)
     {
         float influence = this->getScene ()->getCameraParallaxMouseInfluence ();
         float amount = this->getScene ()->getCameraParallaxAmount ();
-        float delay = this->getScene ()->getCameraParallaxDelay ();
+        float delay = glm::min ((float) this->getScene ()->getCameraParallaxDelay (), g_Time - g_TimeLast);
 
-        this->m_parallaxDisplacement.x = glm::mix (this->m_parallaxDisplacement.x, (this->m_mousePosition.x * amount) * influence, delay);
-        this->m_parallaxDisplacement.y = glm::mix (this->m_parallaxDisplacement.y, (this->m_mousePosition.y * amount) * influence, delay);
+        this->m_parallaxDisplacement = glm::mix (this->m_parallaxDisplacement, (this->m_mousePosition * amount) * influence, delay);
     }
 
     // use the scene's framebuffer by default
@@ -262,6 +264,10 @@ void CScene::updateMouse (glm::ivec4 viewport)
     CMouseInput* mouse = this->getContext ()->getMouse ();
     // TODO: PROPERLY TRANSLATE THESE TO WHAT'S VISIBLE ON SCREEN (FOR BACKGROUNDS THAT DO NOT EXACTLY FIT ON SCREEN)
 
+    // rollover the position to the last
+    this->m_mousePositionLast = this->m_mousePosition;
+
+    // calculate the current position of the mouse
     this->m_mousePosition.x = glm::clamp ((mouse->position.x - viewport.x) / viewport.z, 0.0, 1.0);
     this->m_mousePosition.y = glm::clamp ((mouse->position.y - viewport.y) / viewport.w, 0.0, 1.0);
 
@@ -278,6 +284,10 @@ glm::vec2* CScene::getMousePosition ()
     return &this->m_mousePosition;
 }
 
+glm::vec2* CScene::getMousePositionLast ()
+{
+    return &this->m_mousePositionLast;
+}
 
 glm::vec2* CScene::getParallaxDisplacement ()
 {

src/WallpaperEngine/Render/CScene.h

@@ -22,6 +22,7 @@ namespace WallpaperEngine::Render
         Core::CScene* getScene ();
 
         glm::vec2* getMousePosition ();
+        glm::vec2* getMousePositionLast ();
         glm::vec2* getParallaxDisplacement ();
 
     protected:
@@ -40,6 +41,7 @@ namespace WallpaperEngine::Render
         std::map<int, CObject*> m_objects;
         std::vector<CObject*> m_objectsByRenderOrder;
         glm::vec2 m_mousePosition;
+        glm::vec2 m_mousePositionLast;
         glm::vec2 m_parallaxDisplacement;
         CFBO* _rt_4FrameBuffer;
         CFBO* _rt_8FrameBuffer;

src/WallpaperEngine/Render/Objects/Effects/CPass.cpp

@@ -628,10 +628,11 @@ void CPass::setupUniforms ()
     // add model-view-projection matrix
     this->addUniform ("g_ModelViewProjectionMatrix", &this->m_modelViewProjectionMatrix);
     this->addUniform ("g_PointerPosition", this->m_material->getImage ()->getScene ()->getMousePosition ());
+    this->addUniform ("g_PointerPositionLast", this->m_material->getImage ()->getScene ()->getMousePositionLast ());
     this->addUniform ("g_EffectTextureProjectionMatrix", glm::mat4(1.0));
     this->addUniform ("g_EffectTextureProjectionMatrixInverse", glm::mat4(1.0));
     this->addUniform ("g_TexelSize", glm::vec2 (1.0 / projection->getWidth (), 1.0 / projection->getHeight ()));
-    this->addUniform ("g_TexelSize", glm::vec2 (0.5 / projection->getWidth (), 0.5 / projection->getHeight ()));
+    this->addUniform ("g_TexelSizeHalf", glm::vec2 (0.5 / projection->getWidth (), 0.5 / projection->getHeight ()));
 }
 
 void CPass::addAttribute (const std::string& name, GLint type, GLint elements, const GLuint* value)