feat(glfw): remove glew dependency and use glad instead (#9319)

Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

docs/src/integration/embedded_linux/drivers/glfw.rst

@@ -19,14 +19,12 @@ Getting Started with GLFW
 Prerequisites
 ~~~~~~~~~~~~~
 
-The GLFW driver uses GLEW GLFW to access the OpenGL window manager.
-
-1. Install GLEW and GLFW: ``sudo apt-get install libglew-dev libglfw3-dev``
+1. Install GLFW: ``sudo apt-get install libglfw3-dev``
 
 Configure GLFW Driver
 ~~~~~~~~~~~~~~~~~~~~~
 
-1. Required linked libraries: -lGL -lGLEW -lglfw
+1. Required linked libraries: -lGL -lglfw
 2. Enable the OpenGL driver support in lv_conf.h, by cmake compiler define or by KConfig
 
     .. code-block:: c
@@ -92,7 +90,6 @@ used to add content to a texture and the driver will draw the texture in the win
 .. code-block:: c
 
     #include "lvgl/lvgl.h"
-    #include <GL/glew.h>
     #include <GLFW/glfw3.h>
 
     #define WIDTH 640

scripts/install-prerequisites.bat

@@ -1,4 +1,4 @@
-vcpkg install vcpkg-tool-ninja libpng freetype opengl glfw3 glew
+vcpkg install vcpkg-tool-ninja libpng freetype opengl glfw3
 if %errorlevel% neq 0 exit /b %errorlevel%
 pip install pypng lz4 kconfiglib
 if %errorlevel% neq 0 exit /b %errorlevel%

scripts/prerequisites-apt.txt

@@ -7,7 +7,6 @@ libpng-dev
 libjpeg-turbo8-dev
 libwebp-dev
 libfreetype-dev
-libglew-dev
 libglfw3-dev
 libsdl2-dev
 libpng-dev:i386

src/drivers/opengles/glad/README.md

@@ -1,5 +1,5 @@
-
 # glad
 
 GLAD source files are generated using GLAD's online generator. 
-[Permalink](https://gen.glad.sh/#generator=c&api=egl%3D1.5%2Cgles2%3D2.0&profile=gl%3Dcompatibility%2Cgles1%3Dcommon&extensions=EGL_EXT_image_dma_buf_import%2CEGL_EXT_image_dma_buf_import_modifiers%2CEGL_EXT_platform_base%2CEGL_EXT_platform_wayland%2CEGL_KHR_fence_sync%2CEGL_KHR_image_base%2CEGL_KHR_platform_gbm%2CEGL_KHR_platform_wayland%2CGL_APPLE_texture_max_level%2CGL_ARM_rgba8%2CGL_EXT_color_buffer_float%2CGL_EXT_color_buffer_half_float%2CGL_EXT_texture_format_BGRA8888%2CGL_EXT_texture_storage%2CGL_EXT_unpack_subimage%2CGL_OES_depth24%2CGL_OES_mapbuffer%2CGL_OES_rgb8_rgba8%2CGL_OES_texture_float%2CGL_OES_texture_half_float%2CGL_OES_texture_storage_multisample_2d_array%2CGL_OES_vertex_array_object&options=ALIAS)
+
+[Permalink](https://gen.glad.sh/#generator=c&api=egl%3D1.5%2Cgl%3D3.3%2Cgles2%3D2.0&profile=gl%3Dcompatibility%2Cgles1%3Dcommon&extensions=EGL_EXT_image_dma_buf_import%2CEGL_EXT_image_dma_buf_import_modifiers%2CEGL_EXT_platform_base%2CEGL_EXT_platform_wayland%2CEGL_KHR_fence_sync%2CEGL_KHR_image_base%2CEGL_KHR_platform_gbm%2CGL_APPLE_texture_max_level%2CGL_ARM_rgba8%2CGL_EXT_color_buffer_float%2CGL_EXT_color_buffer_half_float%2CGL_EXT_texture_format_BGRA8888%2CGL_EXT_texture_storage%2CGL_EXT_unpack_subimage%2CGL_OES_depth24%2CGL_OES_mapbuffer%2CGL_OES_rgb8_rgba8%2CGL_OES_texture_float%2CGL_OES_texture_half_float%2CGL_OES_texture_storage_multisample_2d_array%2CGL_OES_vertex_array_object&options=ALIAS%2CALIAS)

src/drivers/opengles/glad/include/EGL/eglplatform.h

@@ -1,9 +1,8 @@
 #ifndef __eglplatform_h_
 #define __eglplatform_h_
 
-#include "../../../lv_opengles_egl.h"
-
-#if LV_USE_EGL
+#include "../../../../../lv_conf_internal.h"
+#if LV_USE_OPENGLES
 
 /*
 ** Copyright 2007-2020 The Khronos Group Inc.
@@ -176,6 +175,5 @@ typedef khronos_int32_t EGLint;
 #define EGL_CAST(type, value) ((type) (value))
 #endif
 
-#endif /*LV_USE_EGL*/
-
+#endif /*LV_USE_OPENGLES*/
 #endif /* __eglplatform_h */

src/drivers/opengles/glad/include/KHR/khrplatform.h

@@ -1,10 +1,8 @@
 #ifndef __khrplatform_h_
 #define __khrplatform_h_
 
-#include "../../../lv_opengles_egl.h"
-
-#if LV_USE_EGL
-
+#include "../../../../../lv_conf_internal.h"
+#if LV_USE_OPENGLES
 /*
 ** Copyright (c) 2008-2018 The Khronos Group Inc.
 **
@@ -312,6 +310,5 @@ typedef enum {
     KHRONOS_BOOLEAN_ENUM_FORCE_SIZE = KHRONOS_MAX_ENUM
 } khronos_boolean_enum_t;
 
-#endif /* LV_USE_EGL */
-
+#endif /*LV_USE_OPENGLES*/
 #endif /* __khrplatform_h_ */

src/drivers/opengles/glad/include/glad/egl.h

@@ -1,11 +1,11 @@
 /**
- * Loader generated by glad 2.0.8 on Tue Sep 30 16:40:42 2025
+ * Loader generated by glad 2.0.8 on Fri Nov 28 10:05:15 2025
  *
  * SPDX-License-Identifier: (WTFPL OR CC0-1.0) AND Apache-2.0
  *
  * Generator: C/C++
  * Specification: egl
- * Extensions: 11
+ * Extensions: 10
  *
  * APIs:
  *  - egl=1.5
@@ -19,18 +19,18 @@
  *  - ON_DEMAND = False
  *
  * Commandline:
- *    --api='egl=1.5' --extensions='EGL_EXT_image_dma_buf_import,EGL_EXT_image_dma_buf_import_modifiers,EGL_EXT_platform_base,EGL_EXT_platform_wayland,EGL_KHR_cl_event2,EGL_KHR_fence_sync,EGL_KHR_image,EGL_KHR_image_base,EGL_KHR_platform_gbm,EGL_KHR_platform_wayland,EGL_KHR_reusable_sync' c --alias
+ *    --api='egl=1.5' --extensions='EGL_EXT_image_dma_buf_import,EGL_EXT_image_dma_buf_import_modifiers,EGL_EXT_platform_base,EGL_EXT_platform_wayland,EGL_KHR_cl_event2,EGL_KHR_fence_sync,EGL_KHR_image,EGL_KHR_image_base,EGL_KHR_platform_gbm,EGL_KHR_reusable_sync' c --alias
  *
  * Online:
- *    http://glad.sh/#api=egl%3D1.5&extensions=EGL_EXT_image_dma_buf_import%2CEGL_EXT_image_dma_buf_import_modifiers%2CEGL_EXT_platform_base%2CEGL_EXT_platform_wayland%2CEGL_KHR_cl_event2%2CEGL_KHR_fence_sync%2CEGL_KHR_image%2CEGL_KHR_image_base%2CEGL_KHR_platform_gbm%2CEGL_KHR_platform_wayland%2CEGL_KHR_reusable_sync&generator=c&options=ALIAS
+ *    http://glad.sh/#api=egl%3D1.5&extensions=EGL_EXT_image_dma_buf_import%2CEGL_EXT_image_dma_buf_import_modifiers%2CEGL_EXT_platform_base%2CEGL_EXT_platform_wayland%2CEGL_KHR_cl_event2%2CEGL_KHR_fence_sync%2CEGL_KHR_image%2CEGL_KHR_image_base%2CEGL_KHR_platform_gbm%2CEGL_KHR_reusable_sync&generator=c&options=ALIAS
  *
  */
 
 #ifndef GLAD_EGL_H_
 #define GLAD_EGL_H_
 
-#include "../../../lv_opengles_egl.h"
 
+#include "../../../../../lv_conf_internal.h"
 #if LV_USE_EGL
 
 #define GLAD_EGL
@@ -470,8 +470,6 @@ GLAD_API_CALL int GLAD_EGL_KHR_image;
 GLAD_API_CALL int GLAD_EGL_KHR_image_base;
 #define EGL_KHR_platform_gbm 1
 GLAD_API_CALL int GLAD_EGL_KHR_platform_gbm;
-#define EGL_KHR_platform_wayland 1
-GLAD_API_CALL int GLAD_EGL_KHR_platform_wayland;
 #define EGL_KHR_reusable_sync 1
 GLAD_API_CALL int GLAD_EGL_KHR_reusable_sync;
 
@@ -660,6 +658,6 @@ GLAD_API_CALL int gladLoadEGL(EGLDisplay display, GLADloadfunc load);
 #ifdef __cplusplus
 }
 #endif
-#endif /*LV_USE_EGL*/
 
+#endif /*LV_USE_EGL*/
 #endif

src/drivers/opengles/glad/include/glad/gles2.h

@@ -1,5 +1,5 @@
 /**
- * Loader generated by glad 2.0.8 on Tue Sep 30 16:40:43 2025
+ * Loader generated by glad 2.0.8 on Fri Nov 28 10:05:18 2025
  *
  * SPDX-License-Identifier: (WTFPL OR CC0-1.0) AND Apache-2.0
  *
@@ -29,8 +29,7 @@
 #ifndef GLAD_GLES2_H_
 #define GLAD_GLES2_H_
 
-#include "../../../lv_opengles_egl.h"
-
+#include "../../../../../lv_conf_internal.h"
 #if LV_USE_EGL
 
 #ifdef __clang__
@@ -1106,6 +1105,6 @@ GLAD_API_CALL int gladLoadGLES2( GLADloadfunc load);
 #ifdef __cplusplus
 }
 #endif
-#endif /*LV_USE_EGL*/
 
+#endif /*LV_USE_EGL*/
 #endif

src/drivers/opengles/glad/src/egl.c

@@ -2,10 +2,8 @@
  * SPDX-License-Identifier: (WTFPL OR CC0-1.0) AND Apache-2.0
  */
 
- #include "../../lv_opengles_egl.h"
-
+#include "../../lv_opengles_private.h"
 #if LV_USE_EGL
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -43,7 +41,6 @@ int GLAD_EGL_KHR_fence_sync = 0;
 int GLAD_EGL_KHR_image = 0;
 int GLAD_EGL_KHR_image_base = 0;
 int GLAD_EGL_KHR_platform_gbm = 0;
-int GLAD_EGL_KHR_platform_wayland = 0;
 int GLAD_EGL_KHR_reusable_sync = 0;
 
 
@@ -262,7 +259,6 @@ static int glad_egl_find_extensions_egl(EGLDisplay display) {
     GLAD_EGL_KHR_image = glad_egl_has_extension(extensions, "EGL_KHR_image");
     GLAD_EGL_KHR_image_base = glad_egl_has_extension(extensions, "EGL_KHR_image_base");
     GLAD_EGL_KHR_platform_gbm = glad_egl_has_extension(extensions, "EGL_KHR_platform_gbm");
-    GLAD_EGL_KHR_platform_wayland = glad_egl_has_extension(extensions, "EGL_KHR_platform_wayland");
     GLAD_EGL_KHR_reusable_sync = glad_egl_has_extension(extensions, "EGL_KHR_reusable_sync");
 
     return 1;

src/drivers/opengles/glad/src/gles2.c

@@ -1,7 +1,8 @@
 /**
  * SPDX-License-Identifier: (WTFPL OR CC0-1.0) AND Apache-2.0
  */
-#include "../../lv_opengles_egl.h"
+
+#include "../../lv_opengles_private.h"
 
 #if LV_USE_EGL
 

src/drivers/opengles/lv_opengles_glfw.c

@@ -68,7 +68,7 @@ static uint32_t lv_glfw_tick_count_callback(void);
 static lv_opengles_window_t * lv_glfw_get_lv_window_from_window(GLFWwindow * window);
 static void glfw_error_cb(int error, const char * description);
 static int lv_glfw_init(void);
-static int lv_glew_init(void);
+static lv_result_t lv_glad_init(void);
 static void lv_glfw_timer_init(void);
 static void lv_glfw_window_config(GLFWwindow * window, bool use_mouse_indev);
 static void lv_glfw_window_quit(void);
@@ -89,7 +89,7 @@ static void window_display_flush_cb(lv_display_t * disp, const lv_area_t * area,
  *  STATIC VARIABLES
  **********************/
 static bool glfw_inited;
-static bool glew_inited;
+static bool glad_inited;
 static lv_timer_t * update_handler_timer;
 static lv_ll_t glfw_window_ll;
 #if !LV_USE_DRAW_OPENGLES
@@ -149,7 +149,16 @@ lv_opengles_window_t * lv_opengles_glfw_window_create_ex(int32_t hor_res, int32_
     glfwSetWindowUserPointer(window->window, window);
     lv_glfw_timer_init();
     lv_glfw_window_config(window->window, use_mouse_indev);
-    lv_glew_init();
+
+    lv_result_t res = lv_glad_init();
+    if(res != LV_RESULT_OK) {
+        LV_LOG_ERROR("Failed to init glad");
+        glfwDestroyWindow(window->window);
+        lv_ll_remove(&glfw_window_ll, window);
+        lv_free(window);
+        return NULL;
+    }
+
     glfwMakeContextCurrent(window->window);
     lv_opengles_init();
 
@@ -384,24 +393,24 @@ static int lv_glfw_init(void)
     return 0;
 }
 
-static int lv_glew_init(void)
+static lv_result_t lv_glad_init(void)
 {
-    if(glew_inited) {
-        return 0;
+    if(glad_inited) {
+        return LV_RESULT_OK;
     }
 
-    GLenum ret = glewInit();
-    if(ret != GLEW_OK) {
-        LV_LOG_ERROR("glewInit fail: %d.", ret);
-        return ret;
+
+    if(!gladLoadGL((GLADloadfunc)glfwGetProcAddress)) {
+        LV_LOG_ERROR("Failed to load OpenGL functions");
+        return LV_RESULT_INVALID;
     }
 
     LV_LOG_INFO("GL version: %s", glGetString(GL_VERSION));
     LV_LOG_INFO("GLSL version: %s", glGetString(GL_SHADING_LANGUAGE_VERSION));
 
-    glew_inited = true;
+    glad_inited = true;
 
-    return 0;
+    return LV_RESULT_OK;
 }
 
 static void lv_glfw_timer_init(void)
@@ -513,7 +522,7 @@ static void window_update_handler(lv_timer_t * t)
                 GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, lv_area_get_width(&texture->area), lv_area_get_height(&texture->area), 0,
                                      GL_RED, GL_UNSIGNED_BYTE, texture->fb));
 #elif LV_COLOR_DEPTH == 16
-                GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB565, lv_area_get_width(&texture->area), lv_area_get_height(&texture->area),
+                GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, lv_area_get_width(&texture->area), lv_area_get_height(&texture->area),
                                      0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5,
                                      texture->fb));
 #elif LV_COLOR_DEPTH == 24

src/drivers/opengles/lv_opengles_private.h

@@ -15,6 +15,7 @@ extern "C" {
  *********************/
 
 #include "../../lv_conf_internal.h"
+
 #if LV_USE_OPENGLES
 
 #include "../../misc/lv_area.h"
@@ -24,12 +25,13 @@ extern "C" {
 #include "glad/include/glad/gles2.h"
 #include "glad/include/glad/egl.h"
 #else
-/* For now, by default we add glew and glfw.
-   In the future we need to consider adding a config for setting these includes*/
-#include <GL/glew.h>
-#include <GLFW/glfw3.h>
+#include "glad/include/glad/gl.h"
 #endif /*LV_USE_EGL*/
 
+#if LV_USE_GLFW
+#include <GLFW/glfw3.h>
+#endif
+
 /*********************
  *      DEFINES
  *********************/

src/drivers/opengles/lv_opengles_texture.c

@@ -205,7 +205,7 @@ static unsigned int create_texture(int32_t w, int32_t h)
     /* set the dimensions and format to complete the texture */
     /* Color depth: 16 (RGB565), 32 (XRGB8888) */
 #if LV_COLOR_DEPTH == 16
-    GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB565, w, h, 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5,
+    GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5,
                          NULL));
 #elif LV_COLOR_DEPTH == 32
     GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL));
@@ -248,7 +248,7 @@ static void flush_cb(lv_display_t * disp, const lv_area_t * area, uint8_t * px_m
         GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, stride / lv_color_format_get_size(cf)));
         /*Color depth: 16 (RGB565), 32 (XRGB8888)*/
 #if LV_COLOR_DEPTH == 16
-        GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB565, disp->hor_res, disp->ver_res, 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5,
+        GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, disp->hor_res, disp->ver_res, 0, GL_RGB, GL_UNSIGNED_SHORT_5_6_5,
                              dsc->fb1));
 #elif LV_COLOR_DEPTH == 32
         GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, disp->hor_res, disp->ver_res, 0, GL_RGBA, GL_UNSIGNED_BYTE, dsc->fb1));

tests/CMakeLists.txt

@@ -416,21 +416,19 @@ endif()
 
 # OpenGL ES is required for its driver
 if ($ENV{NON_AMD64_BUILD})
-    message("Disable OpenGL, GLEW or glfw3 for non-amd64 build")
+    message("Disable OpenGL, glfw3 for non-amd64 build")
     add_definitions(-DLV_USE_OPENGLES=0)
 else()
     find_package(OpenGL)
-    find_package(GLEW)
     find_package(glfw3)
 
-    if(OpenGL_FOUND AND GLEW_FOUND AND glfw3_FOUND)
+    if(OpenGL_FOUND AND glfw3_FOUND)
         # Include directories
         include_directories(${OPENGL_INCLUDE_DIR})
-        include_directories(${GLEW_INCLUDE_DIRS})
         include_directories(${GLFW_INCLUDE_DIRS})
         message("Enable LV_USE_OPENGLES")
     else()
-        message("OpenGL, GLEW or glfw3 not found, defaulting to 0")
+        message("OpenGL, glfw3 not found, defaulting to 0")
         add_definitions(-DLV_USE_OPENGLES=0)
     endif()
 endif()
@@ -534,7 +532,7 @@ foreach( test_case_fname ${TEST_CASE_FILES} )
 
 	if (NOT $ENV{NON_AMD64_BUILD})
 	    target_link_libraries(${test_name} PRIVATE
-    	        ${OPENGL_LIBRARIES} ${GLEW_LIBRARIES} glfw)
+    	        ${OPENGL_LIBRARIES} glfw)
 	endif()
 
     target_include_directories(${test_name} PUBLIC ${TEST_INCLUDE_DIRS})