From c7228611128c17b7678379b636759cdbc5f58d80 Mon Sep 17 00:00:00 2001
From: kub <derkub@gmail.com>
Date: Fri, 16 Sep 2022 17:07:14 +0000
Subject: [PATCH] make gl layer reinitializable

---
 gl.c       | 30 ++++++++++++++++++++----------
 gl.h       |  4 ++--
 plat_sdl.c |  8 +++++---
 3 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/gl.c b/gl.c
index 0e18c45..3f72c77 100644
--- a/gl.c
+++ b/gl.c
@@ -10,10 +10,15 @@ static EGLDisplay edpy;
 static EGLSurface esfc;
 static EGLContext ectxt;
 
+static GLuint texture_name;
+
 /* for external flips */
 void *gl_es_display;
 void *gl_es_surface;
 
+static int tex_w, tex_h;
+static void *tex_mem;
+
 static int gl_have_error(const char *name)
 {
 	GLenum e = glGetError();
@@ -34,11 +39,9 @@ static int gles_have_error(const char *name)
 	return 0;
 }
 
-int gl_init(void *display, void *window, int *quirks)
+int gl_init(void *display, void *window, int *quirks, int w, int h)
 {
 	EGLConfig ecfg = NULL;
-	GLuint texture_name = 0;
-	void *tmp_texture_mem = NULL;
 	EGLint num_config;
 	int retval = -1;
 	int ret;
@@ -53,8 +56,10 @@ int gl_init(void *display, void *window, int *quirks)
 		goto out;
 	}
 
-	tmp_texture_mem = calloc(1, 1024 * 512 * 2);
-	if (tmp_texture_mem == NULL) {
+	for (tex_w = 1; tex_w < w; tex_w *= 2);
+	for (tex_h = 1; tex_h < h; tex_h *= 2);
+	tex_mem = realloc(tex_mem, tex_w * tex_h * 2);
+	if (tex_mem == NULL) {
 		fprintf(stderr, "OOM\n");
 		goto out;
 	}
@@ -99,12 +104,15 @@ int gl_init(void *display, void *window, int *quirks)
 
 	glEnable(GL_TEXTURE_2D);
 
+	if (texture_name)
+		glDeleteTextures(1, &texture_name);
+
 	glGenTextures(1, &texture_name);
 
 	glBindTexture(GL_TEXTURE_2D, texture_name);
 
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 1024, 512, 0, GL_RGB,
-		GL_UNSIGNED_SHORT_5_6_5, tmp_texture_mem);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, tex_w, tex_h, 0, GL_RGB,
+		GL_UNSIGNED_SHORT_5_6_5, tex_mem);
 	if (gl_have_error("glTexImage2D"))
 		goto out;
 
@@ -127,7 +135,6 @@ int gl_init(void *display, void *window, int *quirks)
 	gl_es_surface = (void *)esfc;
 	retval = 0;
 out:
-	free(tmp_texture_mem);
 	return retval;
 }
 
@@ -156,8 +163,8 @@ int gl_flip(const void *fb, int w, int h)
 
 	if (fb != NULL) {
 		if (w != old_w || h != old_h) {
-			float f_w = (float)w / 1024.0f;
-			float f_h = (float)h / 512.0f;
+			float f_w = (float)w / tex_w;
+			float f_h = (float)h / tex_h;
 			texture[1*2 + 0] = f_w;
 			texture[2*2 + 1] = f_h;
 			texture[3*2 + 0] = f_w;
@@ -199,5 +206,8 @@ void gl_finish(void)
 	gl_es_display = (void *)edpy;
 	gl_es_surface = (void *)esfc;
 
+	if (tex_mem) free(tex_mem);
+	tex_mem = NULL;
+
 	gl_platform_finish();
 }
diff --git a/gl.h b/gl.h
index ed1f977..bddacdc 100644
--- a/gl.h
+++ b/gl.h
@@ -3,7 +3,7 @@
 
 #ifdef HAVE_GLES
 
-int  gl_init(void *display, void *window, int *quirks);
+int  gl_init(void *display, void *window, int *quirks, int w, int h);
 void gl_announce(void);
 int  gl_flip(const void *fb, int w, int h);
 void gl_finish(void);
@@ -14,7 +14,7 @@ extern void *gl_es_surface;
 
 #else
 
-static __inline int gl_init(void *display, void *window, int *quirks)
+static __inline int gl_init(void *display, void *window, int *quirks, int w, int h)
 {
   return -1;
 }
diff --git a/plat_sdl.c b/plat_sdl.c
index cae9490..b5e2665 100644
--- a/plat_sdl.c
+++ b/plat_sdl.c
@@ -117,7 +117,8 @@ int plat_sdl_change_video_mode(int w, int h, int force)
     }
   }
   else if (plat_target.vout_method == vout_mode_gl) {
-    plat_sdl_gl_active = (gl_init(display, window, &gl_quirks) == 0);
+    int sw = plat_sdl_screen->w, sh = plat_sdl_screen->h;
+    plat_sdl_gl_active = (gl_init(display, window, &gl_quirks, sw, sh) == 0);
     if (!plat_sdl_gl_active) {
       fprintf(stderr, "warning: could not init GL.\n");
       plat_target.vout_method = 0;
@@ -185,8 +186,9 @@ void plat_sdl_event_handler(void *event_)
       }
       else if (plat_sdl_gl_active) {
         if (gl_quirks & GL_QUIRK_ACTIVATE_RECREATE) {
+          int sw = plat_sdl_screen->w, sh = plat_sdl_screen->h;
           gl_finish();
-          plat_sdl_gl_active = (gl_init(display, window, &gl_quirks) == 0);
+          plat_sdl_gl_active = (gl_init(display, window, &gl_quirks, sw, sh) == 0);
         }
         gl_flip(NULL, 0, 0);
       }
@@ -311,7 +313,7 @@ int plat_sdl_init(void)
   if (env)
     try_gl = atoi(env);
   if (try_gl)
-    ret = gl_init(display, window, &gl_quirks);
+    ret = gl_init(display, window, &gl_quirks, g_menuscreen_w, g_menuscreen_h);
   if (ret == 0) {
     gl_announce();
     gl_works = 1;
-- 
2.39.2