Add content scale queries
This adds glfwGetWindowContentScale and glfwGetMonitorContentScale for
querying the recommended drawing scale factor for DPI-aware rendering.
Parts of this patch are based on code by @ferreiradaselva.
Fixes #235.
Fixes #439.
Fixes #677.
Fixes #845.
Fixes #898.
diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
index 8e6bc42..0ba409b 100644
--- a/include/GLFW/glfw3.h
+++ b/include/GLFW/glfw3.h
@@ -1926,6 +1926,36 @@
*/
GLFWAPI void glfwGetMonitorPhysicalSize(GLFWmonitor* monitor, int* widthMM, int* heightMM);
+/*! @brief Retrieves the content scale for the specified monitor.
+ *
+ * This function retrieves the content scale for the specified monitor. The
+ * content scale is the ratio between the current DPI and the platform's
+ * default DPI. If you scale all pixel dimensions by this scale then your
+ * content should appear at an appropriate size. This is especially important
+ * for text and any UI elements.
+ *
+ * The content scale may depend on both the monitor resolution and pixel
+ * density and on user settings. It may be very different from the raw DPI
+ * calculated from the physical size and current resolution.
+ *
+ * @param[in] monitor The monitor to query.
+ * @param[out] xscale Where to store the x-axis content scale, or `NULL`.
+ * @param[out] yscale Where to store the y-axis content scale, or `NULL`.
+ *
+ * @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ * GLFW_PLATFORM_ERROR.
+ *
+ * @thread_safety This function must only be called from the main thread.
+ *
+ * @sa @ref monitor_scale
+ * @sa @ref glfwGetWindowContentScale
+ *
+ * @since Added in version 3.3.
+ *
+ * @ingroup monitor
+ */
+GLFWAPI void glfwGetMonitorContentScale(GLFWmonitor* monitor, float* xscale, float* yscale);
+
/*! @brief Returns the name of the specified monitor.
*
* This function returns a human-readable name, encoded as UTF-8, of the
@@ -2774,6 +2804,36 @@
*/
GLFWAPI void glfwGetWindowFrameSize(GLFWwindow* window, int* left, int* top, int* right, int* bottom);
+/*! @brief Retrieves the content scale for the specified window.
+ *
+ * This function retrieves the content scale for the specified window. The
+ * content scale is the ratio between the current DPI and the platform's
+ * default DPI. If you scale all pixel dimensions by this scale then your
+ * content should appear at an appropriate size. This is especially important
+ * for text and any UI elements.
+ *
+ * On systems where each monitors can have its own content scale, the window
+ * content scale will depend on which monitor the system considers the window
+ * to be on.
+ *
+ * @param[in] window The window to query.
+ * @param[out] xscale Where to store the x-axis content scale, or `NULL`.
+ * @param[out] yscale Where to store the y-axis content scale, or `NULL`.
+ *
+ * @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ * GLFW_PLATFORM_ERROR.
+ *
+ * @thread_safety This function must only be called from the main thread.
+ *
+ * @sa @ref window_scale
+ * @sa @ref glfwGetMonitorContentScale
+ *
+ * @since Added in version 3.3.
+ *
+ * @ingroup window
+ */
+GLFWAPI void glfwGetWindowContentScale(GLFWwindow* window, float* xscale, float* yscale);
+
/*! @brief Iconifies the specified window.
*
* This function iconifies (minimizes) the specified window if it was
