kc3-lang/kc3

diff --git a/libc3/window/cairo/quartz/window_cairo_quartz_view.m b/libc3/window/cairo/quartz/window_cairo_quartz_view.m
index 7383305..a98df3c 100644
--- a/libc3/window/cairo/quartz/window_cairo_quartz_view.m
+++ b/libc3/window/cairo/quartz/window_cairo_quartz_view.m
@@ -42,7 +42,7 @@
                                                  self.bounds.size.width,
                                                  self.bounds.size.height);
     cairo_t *cr = cairo_create(surface);
-    if (! self.window_cairo->render(self.window_cairo, cr)) {
+    if (! self.window_cairo->render(self.window_cairo)) {
       [self.window close];
       [self.window release];
       [[NSApplication sharedApplication] stop:nil];
diff --git a/libc3/window/sdl2/disabled/sdl2_sprite.c b/libc3/window/sdl2/disabled/sdl2_sprite.c
new file mode 100644
index 0000000..ba13ab0
--- /dev/null
+++ b/libc3/window/sdl2/disabled/sdl2_sprite.c
@@ -0,0 +1,369 @@
+/* c3
+ * Copyright 2022,2023 kmx.io <contact@kmx.io>
+ *
+ * Permission is hereby granted to use this software granted the above
+ * copyright notice and this permission paragraph are included in all
+ * copies and substantial portions of this software.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
+ * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
+ * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
+ * THIS SOFTWARE.
+ */
+#include <libc3/c3.h>
+#include "sdl2_sprite.h"
+
+void sdl2_sprite_bind (const s_sdl2_sprite *sprite, uw frame)
+{
+  assert(sprite);
+  assert(frame < sprite->frame_count);
+  frame %= sprite->frame_count;
+  assert(glGetError() == GL_NO_ERROR);
+  glBindTexture(GL_TEXTURE_2D, sprite->texture[frame]);
+  assert(glGetError() == GL_NO_ERROR);
+}
+
+void sdl2_sprite_clean (s_sdl2_sprite *sprite)
+{
+  assert(sprite);
+  str_clean(&sprite->path);
+  str_clean(&sprite->real_path);
+  glDeleteTextures(sprite->frame_count, sprite->texture);
+  free(sprite->texture);
+}
+
+static bool png_info_to_gl_info (s32 png_color_type,
+                                 s32 png_bit_depth,
+                                 GLenum *gl_format,
+                                 GLint  *gl_internal_format,
+                                 GLenum *gl_type,
+                                 u8 *components)
+{
+  switch (png_bit_depth) {
+  case 8:  *gl_type = GL_UNSIGNED_BYTE;  break;
+  case 16: *gl_type = GL_UNSIGNED_SHORT; break;
+  default: *gl_type = 0; return false;
+  }
+  switch (png_color_type) {
+  case PNG_COLOR_TYPE_GRAY:
+    *components = 1;
+    *gl_format = GL_RED;
+    switch (png_bit_depth) {
+    case 8:  *gl_internal_format = GL_RED;  break;
+    case 16: *gl_internal_format = GL_RED; break;
+    default: *gl_internal_format = 0; return false;
+    }
+    break;
+  case PNG_COLOR_TYPE_GRAY_ALPHA:
+    *components = 2;
+    *gl_format = GL_RG;
+    switch (png_bit_depth) {
+    case 8:  *gl_internal_format = GL_RG;  break;
+    case 16: *gl_internal_format = GL_RG; break;
+    default: *gl_internal_format = 0; return false;
+    }
+    break;
+  case PNG_COLOR_TYPE_RGB:
+    *components = 3;
+    *gl_format = GL_RGB;
+    switch (png_bit_depth) {
+    case 8:  *gl_internal_format = GL_RGB;  break;
+    case 16: *gl_internal_format = GL_RGB; break;
+    default: *gl_internal_format = 0; return false;
+    }
+    break;
+  case PNG_COLOR_TYPE_RGBA:
+    *components = 4;
+    *gl_format = GL_RGBA;
+    switch (png_bit_depth) {
+    case 8:  *gl_internal_format = GL_RGBA8;  break;
+    case 16: *gl_internal_format = GL_RGBA16; break;
+    default: *gl_internal_format = 0; return false;
+    }
+    break;
+  default:
+    *components = 0;
+    *gl_format = 0;
+    *gl_internal_format = 0;
+    return false;
+  }
+  return true;
+}
+
+s_sdl2_sprite * sdl2_sprite_init (s_sdl2_sprite *sprite,
+                                  const s8 *path,
+                                  uw dim_x, uw dim_y,
+                                  uw frame_count)
+{
+  u8 *data;
+  FILE *fp;
+  GLenum gl_format;
+  GLint  gl_internal_format;
+  GLenum gl_type;
+  uw i;
+  s32         png_bit_depth;
+  s32         png_color_type;
+  u8          png_components;
+  png_bytep   png_data;
+  u32         png_h;
+  u8          png_header[8]; // maximum size is 8
+  png_infop   png_info;
+  uw          png_pixel_size;
+  png_structp png_read;
+  png_bytep  *png_row;
+  u32         png_w;
+  u8 *sprite_data;
+  uw  sprite_stride;
+  uw x;
+  uw y;
+  uw v;
+  assert(sprite);
+  assert(path);
+  assert(dim_x);
+  assert(dim_y);
+  assert(glGetError() == GL_NO_ERROR);
+  sprite->frame_count = (frame_count > 0) ? frame_count :
+    (dim_x * dim_y);
+  str_init_copy_1(&sprite->path, path);
+  if (! file_search(&sprite->path, sym_1("r"), &sprite->real_path)) {
+    err_write_1("sdl2_sprite_init: file not found: ");
+    err_puts(path);
+    str_clean(&sprite->path);
+    return NULL;
+  }
+  fp = fopen(sprite->real_path.ptr.ps8, "rb");
+  if (! fp) {
+    err_write_1("sdl2_sprite_init: fopen: ");
+    err_puts(sprite->real_path.ptr.ps8);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  if (fread(png_header, 1, sizeof(png_header), fp) !=
+      sizeof(png_header)) {
+    err_write_1("sdl2_sprite_init: fread: ");
+    err_puts(sprite->real_path.ptr.ps8);
+    fclose(fp);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  if (png_sig_cmp(png_header, 0, sizeof(png_header))) {
+    err_write_1("sdl2_sprite_init: not a png: ");
+    err_puts(sprite->real_path.ptr.ps8);
+    fclose(fp);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  png_read = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL,
+				    NULL);
+  if (! png_read) {
+    err_write_1("sdl2_sprite_init: png_create_read_struct: ");
+    err_puts(sprite->real_path.ptr.ps8);
+    fclose(fp);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  png_info = png_create_info_struct(png_read);
+  if (! png_info) {
+    err_write_1("sdl2_sprite_init: png_create_info_struct: ");
+    err_puts(sprite->real_path.ptr.ps8);
+    png_destroy_read_struct(&png_read, NULL, NULL);
+    fclose(fp);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  gl_internal_format = 0;
+  gl_format = 0;
+  gl_type = 0;
+  png_components = 0;
+  if (setjmp(png_jmpbuf(png_read))) {
+    png_destroy_read_struct(&png_read, &png_info, NULL);
+    fclose(fp);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  png_set_sig_bytes(png_read, sizeof(png_header));
+  png_init_io(png_read, fp);
+  png_read_info(png_read, png_info);
+  png_get_IHDR(png_read, png_info, &png_w, &png_h,
+	       &png_bit_depth, &png_color_type,
+	       NULL, NULL, NULL);
+  if (png_color_type == PNG_COLOR_TYPE_PALETTE)
+    png_set_palette_to_rgb(png_read);
+  if (! png_info_to_gl_info(png_color_type, png_bit_depth, &gl_format,
+			    &gl_internal_format, &gl_type,
+			    &png_components)) {
+    if (! gl_format || ! png_components) {
+      err_write_1("sdl2_sprite_init: unknown PNG color type ");
+      err_inspect_s32(&png_color_type);
+      err_write_1(": ");
+      err_puts(sprite->real_path.ptr.ps8);
+    }
+    if (! gl_internal_format) {
+      err_write_1("sdl2_sprite_init: unknown OpenGL internal format: ");
+      err_puts(sprite->real_path.ptr.ps8);
+    }
+    if (! gl_type) {
+      err_write_1("sdl2_sprite_init: unknown OpenGL type: ");
+      err_puts(sprite->real_path.ptr.ps8);
+    }
+    png_destroy_read_struct(&png_read, &png_info, NULL);
+    fclose(fp);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  png_pixel_size = (png_bit_depth / 8) * png_components;
+  if (! png_pixel_size)
+    png_error(png_read, "unknown png pixel size");
+  if (png_h > PNG_SIZE_MAX / (png_w * png_pixel_size))
+    png_error(png_read, "image_data buffer would be too large");
+  png_data = png_malloc(png_read, png_h * png_w * png_pixel_size);
+  png_row = png_malloc(png_read, png_h * sizeof(png_bytep));
+  i = 0;
+  while (i < png_h) {
+    png_row[i] = png_data + i * png_w * png_pixel_size;
+    i++;
+  }
+  if (png_bit_depth < 8)
+    png_set_packing(png_read);
+  png_read_image(png_read, png_row);
+  png_destroy_read_struct(&png_read, &png_info, NULL);
+  fclose(fp);
+  sprite->total_w = png_w;
+  sprite->total_h = png_h;
+  sprite->dim_x = dim_x;
+  sprite->dim_y = dim_y;
+  sprite->w = sprite->total_w / dim_x;
+  sprite->h = sprite->total_h / dim_y;
+  sprite->texture = calloc(sprite->frame_count, sizeof(GLuint));
+  if (! sprite->texture) {
+    err_puts("sdl2_sprite_init: sprite->texture:"
+             " failed to allocate memory");
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  glGenTextures(sprite->frame_count, sprite->texture);
+  GLenum gl_error = glGetError();
+  if (gl_error != GL_NO_ERROR) {
+    err_write_1("sdl2_sprite_init: ");
+    err_inspect_str(&sprite->real_path);
+    err_write_1(": glGenTextures: ");
+    err_puts((const s8 *) gluErrorString(gl_error));
+    free(sprite->texture);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  sprite_stride = sprite->w * png_pixel_size;
+  data = malloc(sprite->h * sprite_stride);
+  if (! data) {
+    err_write_1("sdl2_sprite_init: failed to allocate memory: ");
+    err_puts(sprite->real_path.ptr.ps8);
+    free(sprite->texture);
+    str_clean(&sprite->path);
+    str_clean(&sprite->real_path);
+    return NULL;
+  }
+  i = 0;
+  y = 0;
+  while (i < sprite->frame_count && y < dim_y) {
+    x = 0;
+    while (i < sprite->frame_count && x < dim_x) {
+      sprite_data = data + sprite_stride * sprite->h;
+      v = 0;
+      while (v < sprite->h) {
+	sprite_data -= sprite_stride;
+	memcpy(sprite_data,
+	       png_row[y * sprite->h + v] + x * sprite_stride,
+	       sprite_stride);
+	v++;
+      }
+      glBindTexture(GL_TEXTURE_2D, sprite->texture[i]);
+      gl_error = glGetError();
+      if (gl_error != GL_NO_ERROR) {
+	err_write_1("sdl2_sprite_init: ");
+        err_inspect_str(&sprite->real_path);
+        err_write_1(": glBindTexture: ");
+        err_puts((const s8 *) gluErrorString(gl_error));
+	return NULL;
+      }
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
+                      GL_CLAMP_TO_EDGE);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,
+                      GL_CLAMP_TO_EDGE);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
+                      GL_LINEAR_MIPMAP_LINEAR);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+      gl_error = glGetError();
+      if (gl_error != GL_NO_ERROR) {
+	err_write_1("sdl2_sprite_init: ");
+        err_inspect_str(&sprite->real_path);
+        err_write_1(": glTexParameteri: ");
+        err_puts((const s8 *) gluErrorString(gl_error));
+	return NULL;
+      }
+      glTexImage2D(GL_TEXTURE_2D, 0, gl_format, sprite->w, sprite->h,
+                   0, gl_format, gl_type, data);
+      //glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, sprite->w, sprite->h,
+      //             0, GL_RGBA, GL_UNSIGNED_BYTE, data);
+      gl_error = glGetError();
+      if (gl_error != GL_NO_ERROR) {
+	err_write_1("sdl2_sprite_init: ");
+        err_inspect_str(&sprite->real_path);
+        err_write_1(": glTexImage2D: ");
+        err_puts((const s8 *) gluErrorString(gl_error));
+	return NULL;
+      }
+      glGenerateMipmap(GL_TEXTURE_2D);
+      assert(glGetError() == GL_NO_ERROR);
+      i++;
+      x++;
+    }
+    y++;
+  }
+  glBindTexture(GL_TEXTURE_2D, 0);
+  free(data);
+  free(png_data);
+  free(png_row);
+  return sprite;
+}
+
+void sdl2_sprite_render (const s_sdl2_sprite *sprite, uw frame)
+{
+  assert(sprite);
+  assert(frame < sprite->frame_count);
+  frame %= sprite->frame_count;
+  glColor4f(1, 1, 1, 1);
+  glEnable(GL_BLEND);
+  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+  glDisable(GL_CULL_FACE);
+  glEnable(GL_TEXTURE_2D);
+  glBindTexture(GL_TEXTURE_2D, sprite->texture[frame]);
+  glBegin(GL_QUADS); {
+    glTexCoord2f(0, 1);
+    glVertex2d(0, sprite->h);
+    glTexCoord2f(0, 0);
+    glVertex2i(0, 0);
+    glTexCoord2f(1, 0);
+    glVertex2i(sprite->w, 0);
+    glTexCoord2f(1, 1);
+    glVertex2d(sprite->w, sprite->h);  
+  } glEnd();
+  glBindTexture(GL_TEXTURE_2D, 0);
+  glDisable(GL_TEXTURE_2D);
+  /*
+  glBegin(GL_LINE_LOOP); {
+    glVertex2d(0, sprite->h);
+    glVertex2i(0, 0);
+    glVertex2i(sprite->w, 0);
+    glVertex2d(sprite->w, sprite->h);  
+  } glEnd();
+  */
+}
diff --git a/libc3/window/sdl2/disabled/sdl2_sprite.h b/libc3/window/sdl2/disabled/sdl2_sprite.h
new file mode 100644
index 0000000..675992d
--- /dev/null
+++ b/libc3/window/sdl2/disabled/sdl2_sprite.h
@@ -0,0 +1,29 @@
+/* c3
+ * Copyright 2022,2023 kmx.io <contact@kmx.io>
+ *
+ * Permission is hereby granted to use this software granted the above
+ * copyright notice and this permission paragraph are included in all
+ * copies and substantial portions of this software.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
+ * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
+ * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
+ * THIS SOFTWARE.
+ */
+#ifndef SDL2_SPRITE_H
+#define SDL2_SPRITE_H
+
+#include "types.h"
+
+/* stack allocation compatible functions */
+void            sdl2_sprite_clean (s_sdl2_sprite *sprite);
+s_sdl2_sprite * sdl2_sprite_init (s_sdl2_sprite *sprite,
+                                  const s8 *path,
+                                  uw dim_x, uw dim_y,
+                                  uw frame_count);
+
+/* operations */
+void sdl2_sprite_bind (const s_sdl2_sprite *sprite, uw frame);
+void sdl2_sprite_render (const s_sdl2_sprite *sprite, uw frame);
+
+#endif /* CAIRO_SPRITE_H */
diff --git a/libc3/window/sdl2/gl_deprecated.c b/libc3/window/sdl2/gl_deprecated.c
new file mode 100644
index 0000000..dd77e39
--- /dev/null
+++ b/libc3/window/sdl2/gl_deprecated.c
@@ -0,0 +1,19 @@
+/* c3
+ * Copyright 2022,2023 kmx.io <contact@kmx.io>
+ *
+ * Permission is hereby granted to use this software granted the above
+ * copyright notice and this permission paragraph are included in all
+ * copies and substantial portions of this software.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
+ * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
+ * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
+ * THIS SOFTWARE.
+ */
+#define GL_SILENCE_DEPRECATION 1
+#include "gl_deprecated.h"
+
+const s8 * gl_error_string (GLenum error)
+{
+  return (const s8 *) gluErrorString(error);
+}
diff --git a/libc3/window/sdl2/gl_deprecated.h b/libc3/window/sdl2/gl_deprecated.h
new file mode 100644
index 0000000..0699465
--- /dev/null
+++ b/libc3/window/sdl2/gl_deprecated.h
@@ -0,0 +1,20 @@
+/* c3
+ * Copyright 2022,2023 kmx.io <contact@kmx.io>
+ *
+ * Permission is hereby granted to use this software granted the above
+ * copyright notice and this permission paragraph are included in all
+ * copies and substantial portions of this software.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
+ * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
+ * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
+ * THIS SOFTWARE.
+ */
+#ifndef GL_DEPRECATED_H
+#define GL_DEPRECATED_H
+
+#include "types.h"
+
+const s8 * gl_error_string (GLenum error);
+
+#endif /* GL_DEPRECATED_H */
diff --git a/libc3/window/sdl2/gl_lines.h b/libc3/window/sdl2/gl_lines.h
index e0fbcce..1c958b5 100644
--- a/libc3/window/sdl2/gl_lines.h
+++ b/libc3/window/sdl2/gl_lines.h
@@ -22,7 +22,7 @@ s_gl_lines * gl_lines_init (s_gl_lines *lines);
 
 /* Heap-allocation functions, call gl_lines_delete after use. */
 void         gl_lines_delete (s_gl_lines *lines);
-s_gl_lines * gl_lines_new ();
+s_gl_lines * gl_lines_new (void);
 
 /* Operators. */
 s_gl_lines * gl_lines_allocate (s_gl_lines *lines, uw lines_count);
diff --git a/libc3/window/sdl2/gl_sprite.c b/libc3/window/sdl2/gl_sprite.c
index b87c764..fb1c54e 100644
--- a/libc3/window/sdl2/gl_sprite.c
+++ b/libc3/window/sdl2/gl_sprite.c
@@ -11,6 +11,7 @@
  * THIS SOFTWARE.
  */
 #include <libc3/c3.h>
+#include "gl_deprecated.h"
 #include "gl_object.h"
 #include "gl_point_2d.h"
 #include "gl_point_3d.h"
@@ -262,7 +263,7 @@ s_gl_sprite * gl_sprite_init (s_gl_sprite *sprite, const s8 *path,
     err_write_1("sdl2_sprite_init: ");
     err_inspect_str(&tmp.real_path);
     err_write_1(": glGenTextures: ");
-    err_puts((const s8 *) gluErrorString(gl_error));
+    err_puts(gl_error_string(gl_error));
     free(tmp.texture);
     str_clean(&tmp.path);
     str_clean(&tmp.real_path);
@@ -298,7 +299,7 @@ s_gl_sprite * gl_sprite_init (s_gl_sprite *sprite, const s8 *path,
 	err_write_1("sdl2_sprite_init: ");
         err_inspect_str(&tmp.real_path);
         err_write_1(": glBindTexture: ");
-        err_puts((const s8 *) gluErrorString(gl_error));
+        err_puts(gl_error_string(gl_error));
 	return NULL;
       }
       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
@@ -313,7 +314,7 @@ s_gl_sprite * gl_sprite_init (s_gl_sprite *sprite, const s8 *path,
 	err_write_1("sdl2_sprite_init: ");
         err_inspect_str(&tmp.real_path);
         err_write_1(": glTexParameteri: ");
-        err_puts((const s8 *) gluErrorString(gl_error));
+        err_puts(gl_error_string(gl_error));
 	return NULL;
       }
       glTexImage2D(GL_TEXTURE_2D, 0, gl_format, tmp.w, tmp.h,
@@ -325,7 +326,7 @@ s_gl_sprite * gl_sprite_init (s_gl_sprite *sprite, const s8 *path,
 	err_write_1("sdl2_sprite_init: ");
         err_inspect_str(&tmp.real_path);
         err_write_1(": glTexImage2D: ");
-        err_puts((const s8 *) gluErrorString(gl_error));
+        err_puts(gl_error_string(gl_error));
 	return NULL;
       }
       glGenerateMipmap(GL_TEXTURE_2D);
diff --git a/libc3/window/sdl2/sdl2_sprite.c b/libc3/window/sdl2/sdl2_sprite.c
deleted file mode 100644
index ba13ab0..0000000
--- a/libc3/window/sdl2/sdl2_sprite.c
+++ /dev/null
@@ -1,369 +0,0 @@
-/* c3
- * Copyright 2022,2023 kmx.io <contact@kmx.io>
- *
- * Permission is hereby granted to use this software granted the above
- * copyright notice and this permission paragraph are included in all
- * copies and substantial portions of this software.
- *
- * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
- * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
- * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
- * THIS SOFTWARE.
- */
-#include <libc3/c3.h>
-#include "sdl2_sprite.h"
-
-void sdl2_sprite_bind (const s_sdl2_sprite *sprite, uw frame)
-{
-  assert(sprite);
-  assert(frame < sprite->frame_count);
-  frame %= sprite->frame_count;
-  assert(glGetError() == GL_NO_ERROR);
-  glBindTexture(GL_TEXTURE_2D, sprite->texture[frame]);
-  assert(glGetError() == GL_NO_ERROR);
-}
-
-void sdl2_sprite_clean (s_sdl2_sprite *sprite)
-{
-  assert(sprite);
-  str_clean(&sprite->path);
-  str_clean(&sprite->real_path);
-  glDeleteTextures(sprite->frame_count, sprite->texture);
-  free(sprite->texture);
-}
-
-static bool png_info_to_gl_info (s32 png_color_type,
-                                 s32 png_bit_depth,
-                                 GLenum *gl_format,
-                                 GLint  *gl_internal_format,
-                                 GLenum *gl_type,
-                                 u8 *components)
-{
-  switch (png_bit_depth) {
-  case 8:  *gl_type = GL_UNSIGNED_BYTE;  break;
-  case 16: *gl_type = GL_UNSIGNED_SHORT; break;
-  default: *gl_type = 0; return false;
-  }
-  switch (png_color_type) {
-  case PNG_COLOR_TYPE_GRAY:
-    *components = 1;
-    *gl_format = GL_RED;
-    switch (png_bit_depth) {
-    case 8:  *gl_internal_format = GL_RED;  break;
-    case 16: *gl_internal_format = GL_RED; break;
-    default: *gl_internal_format = 0; return false;
-    }
-    break;
-  case PNG_COLOR_TYPE_GRAY_ALPHA:
-    *components = 2;
-    *gl_format = GL_RG;
-    switch (png_bit_depth) {
-    case 8:  *gl_internal_format = GL_RG;  break;
-    case 16: *gl_internal_format = GL_RG; break;
-    default: *gl_internal_format = 0; return false;
-    }
-    break;
-  case PNG_COLOR_TYPE_RGB:
-    *components = 3;
-    *gl_format = GL_RGB;
-    switch (png_bit_depth) {
-    case 8:  *gl_internal_format = GL_RGB;  break;
-    case 16: *gl_internal_format = GL_RGB; break;
-    default: *gl_internal_format = 0; return false;
-    }
-    break;
-  case PNG_COLOR_TYPE_RGBA:
-    *components = 4;
-    *gl_format = GL_RGBA;
-    switch (png_bit_depth) {
-    case 8:  *gl_internal_format = GL_RGBA8;  break;
-    case 16: *gl_internal_format = GL_RGBA16; break;
-    default: *gl_internal_format = 0; return false;
-    }
-    break;
-  default:
-    *components = 0;
-    *gl_format = 0;
-    *gl_internal_format = 0;
-    return false;
-  }
-  return true;
-}
-
-s_sdl2_sprite * sdl2_sprite_init (s_sdl2_sprite *sprite,
-                                  const s8 *path,
-                                  uw dim_x, uw dim_y,
-                                  uw frame_count)
-{
-  u8 *data;
-  FILE *fp;
-  GLenum gl_format;
-  GLint  gl_internal_format;
-  GLenum gl_type;
-  uw i;
-  s32         png_bit_depth;
-  s32         png_color_type;
-  u8          png_components;
-  png_bytep   png_data;
-  u32         png_h;
-  u8          png_header[8]; // maximum size is 8
-  png_infop   png_info;
-  uw          png_pixel_size;
-  png_structp png_read;
-  png_bytep  *png_row;
-  u32         png_w;
-  u8 *sprite_data;
-  uw  sprite_stride;
-  uw x;
-  uw y;
-  uw v;
-  assert(sprite);
-  assert(path);
-  assert(dim_x);
-  assert(dim_y);
-  assert(glGetError() == GL_NO_ERROR);
-  sprite->frame_count = (frame_count > 0) ? frame_count :
-    (dim_x * dim_y);
-  str_init_copy_1(&sprite->path, path);
-  if (! file_search(&sprite->path, sym_1("r"), &sprite->real_path)) {
-    err_write_1("sdl2_sprite_init: file not found: ");
-    err_puts(path);
-    str_clean(&sprite->path);
-    return NULL;
-  }
-  fp = fopen(sprite->real_path.ptr.ps8, "rb");
-  if (! fp) {
-    err_write_1("sdl2_sprite_init: fopen: ");
-    err_puts(sprite->real_path.ptr.ps8);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  if (fread(png_header, 1, sizeof(png_header), fp) !=
-      sizeof(png_header)) {
-    err_write_1("sdl2_sprite_init: fread: ");
-    err_puts(sprite->real_path.ptr.ps8);
-    fclose(fp);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  if (png_sig_cmp(png_header, 0, sizeof(png_header))) {
-    err_write_1("sdl2_sprite_init: not a png: ");
-    err_puts(sprite->real_path.ptr.ps8);
-    fclose(fp);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  png_read = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL,
-				    NULL);
-  if (! png_read) {
-    err_write_1("sdl2_sprite_init: png_create_read_struct: ");
-    err_puts(sprite->real_path.ptr.ps8);
-    fclose(fp);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  png_info = png_create_info_struct(png_read);
-  if (! png_info) {
-    err_write_1("sdl2_sprite_init: png_create_info_struct: ");
-    err_puts(sprite->real_path.ptr.ps8);
-    png_destroy_read_struct(&png_read, NULL, NULL);
-    fclose(fp);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  gl_internal_format = 0;
-  gl_format = 0;
-  gl_type = 0;
-  png_components = 0;
-  if (setjmp(png_jmpbuf(png_read))) {
-    png_destroy_read_struct(&png_read, &png_info, NULL);
-    fclose(fp);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  png_set_sig_bytes(png_read, sizeof(png_header));
-  png_init_io(png_read, fp);
-  png_read_info(png_read, png_info);
-  png_get_IHDR(png_read, png_info, &png_w, &png_h,
-	       &png_bit_depth, &png_color_type,
-	       NULL, NULL, NULL);
-  if (png_color_type == PNG_COLOR_TYPE_PALETTE)
-    png_set_palette_to_rgb(png_read);
-  if (! png_info_to_gl_info(png_color_type, png_bit_depth, &gl_format,
-			    &gl_internal_format, &gl_type,
-			    &png_components)) {
-    if (! gl_format || ! png_components) {
-      err_write_1("sdl2_sprite_init: unknown PNG color type ");
-      err_inspect_s32(&png_color_type);
-      err_write_1(": ");
-      err_puts(sprite->real_path.ptr.ps8);
-    }
-    if (! gl_internal_format) {
-      err_write_1("sdl2_sprite_init: unknown OpenGL internal format: ");
-      err_puts(sprite->real_path.ptr.ps8);
-    }
-    if (! gl_type) {
-      err_write_1("sdl2_sprite_init: unknown OpenGL type: ");
-      err_puts(sprite->real_path.ptr.ps8);
-    }
-    png_destroy_read_struct(&png_read, &png_info, NULL);
-    fclose(fp);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  png_pixel_size = (png_bit_depth / 8) * png_components;
-  if (! png_pixel_size)
-    png_error(png_read, "unknown png pixel size");
-  if (png_h > PNG_SIZE_MAX / (png_w * png_pixel_size))
-    png_error(png_read, "image_data buffer would be too large");
-  png_data = png_malloc(png_read, png_h * png_w * png_pixel_size);
-  png_row = png_malloc(png_read, png_h * sizeof(png_bytep));
-  i = 0;
-  while (i < png_h) {
-    png_row[i] = png_data + i * png_w * png_pixel_size;
-    i++;
-  }
-  if (png_bit_depth < 8)
-    png_set_packing(png_read);
-  png_read_image(png_read, png_row);
-  png_destroy_read_struct(&png_read, &png_info, NULL);
-  fclose(fp);
-  sprite->total_w = png_w;
-  sprite->total_h = png_h;
-  sprite->dim_x = dim_x;
-  sprite->dim_y = dim_y;
-  sprite->w = sprite->total_w / dim_x;
-  sprite->h = sprite->total_h / dim_y;
-  sprite->texture = calloc(sprite->frame_count, sizeof(GLuint));
-  if (! sprite->texture) {
-    err_puts("sdl2_sprite_init: sprite->texture:"
-             " failed to allocate memory");
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  glGenTextures(sprite->frame_count, sprite->texture);
-  GLenum gl_error = glGetError();
-  if (gl_error != GL_NO_ERROR) {
-    err_write_1("sdl2_sprite_init: ");
-    err_inspect_str(&sprite->real_path);
-    err_write_1(": glGenTextures: ");
-    err_puts((const s8 *) gluErrorString(gl_error));
-    free(sprite->texture);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  sprite_stride = sprite->w * png_pixel_size;
-  data = malloc(sprite->h * sprite_stride);
-  if (! data) {
-    err_write_1("sdl2_sprite_init: failed to allocate memory: ");
-    err_puts(sprite->real_path.ptr.ps8);
-    free(sprite->texture);
-    str_clean(&sprite->path);
-    str_clean(&sprite->real_path);
-    return NULL;
-  }
-  i = 0;
-  y = 0;
-  while (i < sprite->frame_count && y < dim_y) {
-    x = 0;
-    while (i < sprite->frame_count && x < dim_x) {
-      sprite_data = data + sprite_stride * sprite->h;
-      v = 0;
-      while (v < sprite->h) {
-	sprite_data -= sprite_stride;
-	memcpy(sprite_data,
-	       png_row[y * sprite->h + v] + x * sprite_stride,
-	       sprite_stride);
-	v++;
-      }
-      glBindTexture(GL_TEXTURE_2D, sprite->texture[i]);
-      gl_error = glGetError();
-      if (gl_error != GL_NO_ERROR) {
-	err_write_1("sdl2_sprite_init: ");
-        err_inspect_str(&sprite->real_path);
-        err_write_1(": glBindTexture: ");
-        err_puts((const s8 *) gluErrorString(gl_error));
-	return NULL;
-      }
-      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
-                      GL_CLAMP_TO_EDGE);
-      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,
-                      GL_CLAMP_TO_EDGE);
-      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
-                      GL_LINEAR_MIPMAP_LINEAR);
-      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-      gl_error = glGetError();
-      if (gl_error != GL_NO_ERROR) {
-	err_write_1("sdl2_sprite_init: ");
-        err_inspect_str(&sprite->real_path);
-        err_write_1(": glTexParameteri: ");
-        err_puts((const s8 *) gluErrorString(gl_error));
-	return NULL;
-      }
-      glTexImage2D(GL_TEXTURE_2D, 0, gl_format, sprite->w, sprite->h,
-                   0, gl_format, gl_type, data);
-      //glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, sprite->w, sprite->h,
-      //             0, GL_RGBA, GL_UNSIGNED_BYTE, data);
-      gl_error = glGetError();
-      if (gl_error != GL_NO_ERROR) {
-	err_write_1("sdl2_sprite_init: ");
-        err_inspect_str(&sprite->real_path);
-        err_write_1(": glTexImage2D: ");
-        err_puts((const s8 *) gluErrorString(gl_error));
-	return NULL;
-      }
-      glGenerateMipmap(GL_TEXTURE_2D);
-      assert(glGetError() == GL_NO_ERROR);
-      i++;
-      x++;
-    }
-    y++;
-  }
-  glBindTexture(GL_TEXTURE_2D, 0);
-  free(data);
-  free(png_data);
-  free(png_row);
-  return sprite;
-}
-
-void sdl2_sprite_render (const s_sdl2_sprite *sprite, uw frame)
-{
-  assert(sprite);
-  assert(frame < sprite->frame_count);
-  frame %= sprite->frame_count;
-  glColor4f(1, 1, 1, 1);
-  glEnable(GL_BLEND);
-  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-  glDisable(GL_CULL_FACE);
-  glEnable(GL_TEXTURE_2D);
-  glBindTexture(GL_TEXTURE_2D, sprite->texture[frame]);
-  glBegin(GL_QUADS); {
-    glTexCoord2f(0, 1);
-    glVertex2d(0, sprite->h);
-    glTexCoord2f(0, 0);
-    glVertex2i(0, 0);
-    glTexCoord2f(1, 0);
-    glVertex2i(sprite->w, 0);
-    glTexCoord2f(1, 1);
-    glVertex2d(sprite->w, sprite->h);  
-  } glEnd();
-  glBindTexture(GL_TEXTURE_2D, 0);
-  glDisable(GL_TEXTURE_2D);
-  /*
-  glBegin(GL_LINE_LOOP); {
-    glVertex2d(0, sprite->h);
-    glVertex2i(0, 0);
-    glVertex2i(sprite->w, 0);
-    glVertex2d(sprite->w, sprite->h);  
-  } glEnd();
-  */
-}
diff --git a/libc3/window/sdl2/sdl2_sprite.h b/libc3/window/sdl2/sdl2_sprite.h
deleted file mode 100644
index 675992d..0000000
--- a/libc3/window/sdl2/sdl2_sprite.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/* c3
- * Copyright 2022,2023 kmx.io <contact@kmx.io>
- *
- * Permission is hereby granted to use this software granted the above
- * copyright notice and this permission paragraph are included in all
- * copies and substantial portions of this software.
- *
- * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
- * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
- * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
- * THIS SOFTWARE.
- */
-#ifndef SDL2_SPRITE_H
-#define SDL2_SPRITE_H
-
-#include "types.h"
-
-/* stack allocation compatible functions */
-void            sdl2_sprite_clean (s_sdl2_sprite *sprite);
-s_sdl2_sprite * sdl2_sprite_init (s_sdl2_sprite *sprite,
-                                  const s8 *path,
-                                  uw dim_x, uw dim_y,
-                                  uw frame_count);
-
-/* operations */
-void sdl2_sprite_bind (const s_sdl2_sprite *sprite, uw frame);
-void sdl2_sprite_render (const s_sdl2_sprite *sprite, uw frame);
-
-#endif /* CAIRO_SPRITE_H */
diff --git a/libc3/window/sdl2/sources.mk b/libc3/window/sdl2/sources.mk
index 6589755..f4270ae 100644
--- a/libc3/window/sdl2/sources.mk
+++ b/libc3/window/sdl2/sources.mk
@@ -2,6 +2,7 @@
 HEADERS = \
 	"gl_camera.h" \
 	"gl_cylinder.h" \
+	"gl_deprecated.h" \
 	"gl_font.h" \
 	"gl_ft2.h" \
 	"gl_lines.h" \
@@ -17,13 +18,13 @@ HEADERS = \
 	"gl_text.h" \
 	"gl_triangle.h" \
 	"gl_vertex.h" \
-	"sdl2_sprite.h" \
 	"types.h" \
 	"window_sdl2.h" \
 
 SOURCES = \
 	"gl_camera.c" \
 	"gl_cylinder.c" \
+	"gl_deprecated.c" \
 	"gl_font.c" \
 	"gl_lines.c" \
 	"gl_matrix_4d.c" \
@@ -37,6 +38,5 @@ SOURCES = \
 	"gl_text.c" \
 	"gl_triangle.c" \
 	"gl_vertex.c" \
-	"sdl2_sprite.c" \
 	"window_sdl2.c" \
 
diff --git a/libc3/window/sdl2/sources.sh b/libc3/window/sdl2/sources.sh
index 490c35b..f4cb03a 100644
--- a/libc3/window/sdl2/sources.sh
+++ b/libc3/window/sdl2/sources.sh
@@ -1,3 +1,3 @@
 # sources.sh generated by update_sources
-HEADERS='gl_camera.h gl_cylinder.h gl_font.h gl_ft2.h gl_lines.h gl_matrix_3d.h gl_matrix_4d.h gl_object.h gl_ortho.h gl_point_2d.h gl_point_3d.h gl_sphere.h gl_sprite.h gl_square.h gl_text.h gl_triangle.h gl_vertex.h sdl2_sprite.h types.h window_sdl2.h '
-SOURCES='gl_camera.c gl_cylinder.c gl_font.c gl_lines.c gl_matrix_4d.c gl_object.c gl_ortho.c gl_point_2d.c gl_point_3d.c gl_sphere.c gl_sprite.c gl_square.c gl_text.c gl_triangle.c gl_vertex.c sdl2_sprite.c window_sdl2.c '
+HEADERS='gl_camera.h gl_cylinder.h gl_deprecated.h gl_font.h gl_ft2.h gl_lines.h gl_matrix_3d.h gl_matrix_4d.h gl_object.h gl_ortho.h gl_point_2d.h gl_point_3d.h gl_sphere.h gl_sprite.h gl_square.h gl_text.h gl_triangle.h gl_vertex.h types.h window_sdl2.h '
+SOURCES='gl_camera.c gl_cylinder.c gl_deprecated.c gl_font.c gl_lines.c gl_matrix_4d.c gl_object.c gl_ortho.c gl_point_2d.c gl_point_3d.c gl_sphere.c gl_sprite.c gl_square.c gl_text.c gl_triangle.c gl_vertex.c window_sdl2.c '
diff --git a/libc3/window/sdl2/window_sdl2.c b/libc3/window/sdl2/window_sdl2.c
index 48fa5db..83b9a98 100644
--- a/libc3/window/sdl2/window_sdl2.c
+++ b/libc3/window/sdl2/window_sdl2.c
@@ -15,10 +15,25 @@
 #include <xkbcommon/xkbcommon.h>
 #include <libc3/c3.h>
 #include "../window.h"
+#include "gl_deprecated.h"
 #include "window_sdl2.h"
 
 static bool g_window_sdl2_initialized = false;
 
+static void gl_debug (GLenum source, GLenum type, GLuint id,
+                      GLenum severity, GLsizei length,
+                      const GLchar* message, const void* user_param)
+{
+  (void) source;
+  (void) type;
+  (void) id;
+  (void) severity;
+  (void) length;
+  (void) user_param;
+  err_write_1("gl_debug_callback: ");
+  err_puts(message);
+}
+
 void window_sdl2_clean (s_window_sdl2 *window)
 {
   window_clean((s_window *) window);
@@ -166,9 +181,11 @@ bool window_sdl2_run (s_window_sdl2 *window)
   GLenum gl_error = glGetError();
   if (gl_error != GL_NO_ERROR) {
     warnx("OpenGL initialization error: %s\n",
-          gluErrorString(gl_error));
+          gl_error_string(gl_error));
     goto ko;
   }
+  glEnable(GL_DEBUG_OUTPUT);
+  glDebugMessageCallback(gl_debug, NULL);
   if (SDL_GL_MakeCurrent(sdl_window, context) < 0) {
     warnx("window_sdl2_run: failed to make OpenGL context current: %s",
           SDL_GetError());