From 7f1035730ae71163859256a2dad51327d708581c Mon Sep 17 00:00:00 2001
From: Andrew Belt <andrewpbelt@gmail.com>
Date: Tue, 5 Dec 2017 23:04:54 -0500
Subject: [PATCH] Add gWindowRatio and set window size on each step

---
 include/gui.hpp |  6 ++++++
 src/gui.cpp     | 22 +++++++++++++---------
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/gui.hpp b/include/gui.hpp
index 9df01144..fd6c0e77 100644
--- a/include/gui.hpp
+++ b/include/gui.hpp
@@ -17,8 +17,14 @@ namespace rack {
 extern GLFWwindow *gWindow;
 extern NVGcontext *gVg;
 extern NVGcontext *gFramebufferVg;
+/** The default font to use for GUI elements */
 extern std::shared_ptr<Font> gGuiFont;
+/** The scaling ratio */
 extern float gPixelRatio;
+/* The ratio between the framebuffer size and the window size reported by the OS.
+This is not equal to gPixelRatio in general.
+*/
+extern float gWindowRatio;
 extern bool gAllowCursorLock;
 extern int gGuiFrame;
 extern Vec gMousePos;
diff --git a/src/gui.cpp b/src/gui.cpp
index b74a6988..fdb58ad3 100644
--- a/src/gui.cpp
+++ b/src/gui.cpp
@@ -33,7 +33,8 @@ GLFWwindow *gWindow = NULL;
 NVGcontext *gVg = NULL;
 NVGcontext *gFramebufferVg = NULL;
 std::shared_ptr<Font> gGuiFont;
-float gPixelRatio = 0.0;
+float gPixelRatio = 1.0;
+float gWindowRatio = 1.0;
 bool gAllowCursorLock = true;
 int gGuiFrame;
 Vec gMousePos;
@@ -42,7 +43,6 @@ std::string lastWindowTitle;
 
 
 void windowSizeCallback(GLFWwindow* window, int width, int height) {
-	gScene->box.size = Vec(width, height);
 }
 
 void mouseButtonCallback(GLFWwindow *window, int button, int action, int mods) {
@@ -145,7 +145,7 @@ void mouseButtonStickyCallback(GLFWwindow *window, int button, int action, int m
 }
 
 void cursorPosCallback(GLFWwindow* window, double xpos, double ypos) {
-	Vec mousePos = Vec(xpos, ypos).round();
+	Vec mousePos = Vec(xpos, ypos).div(gPixelRatio / gWindowRatio).round();
 	Vec mouseRel = mousePos.minus(gMousePos);
 
 #ifdef ARCH_MAC
@@ -411,11 +411,6 @@ void guiDestroy() {
 
 void guiRun() {
 	assert(gWindow);
-	{
-		int width, height;
-		glfwGetWindowSize(gWindow, &width, &height);
-		windowSizeCallback(gWindow, width, height);
-	}
 	gGuiFrame = 0;
 	while(!glfwWindowShouldClose(gWindow)) {
 		double startTime = glfwGetTime();
@@ -444,7 +439,7 @@ void guiRun() {
 			lastWindowTitle = windowTitle;
 		}
 
-		// Get framebuffer size
+		// Get desired scaling
 		float pixelRatio;
 		glfwGetWindowContentScale(gWindow, &pixelRatio, NULL);
 		pixelRatio = roundf(pixelRatio);
@@ -454,6 +449,15 @@ void guiRun() {
 			gPixelRatio = pixelRatio;
 		}
 
+		// Get framebuffer/window ratio
+		int width, height;
+		glfwGetFramebufferSize(gWindow, &width, &height);
+		int windowWidth, windowHeight;
+		glfwGetWindowSize(gWindow, &windowWidth, &windowHeight);
+		gWindowRatio = (float)width / windowWidth;
+
+		gScene->box.size = Vec(width, height).div(gPixelRatio / gWindowRatio);
+
 		// Step scene
 		gScene->step();