static inline size_t
_glClearBufferData_size(GLenum format, GLenum type) {
unsigned bits_per_element;
unsigned bits_per_pixel;
_gl_format_size(format, type, bits_per_element, bits_per_pixel);
return (bits_per_pixel + 7)/8;
}
static inline size_t
_gl_image_size(GLenum format, GLenum type, GLsizei width, GLsizei height, GLsizei depth, GLboolean has_unpack_subimage) {
unsigned bits_per_element;
unsigned bits_per_pixel;
_gl_format_size(format, type, bits_per_element, bits_per_pixel);
GLint alignment = 4;
GLint row_length = 0;
GLint image_height = 0;
GLint skip_rows = 0;
GLint skip_pixels = 0;
GLint skip_images = 0;
_glGetIntegerv(GL_UNPACK_ALIGNMENT, &alignment);
if (has_unpack_subimage) {
_glGetIntegerv(GL_UNPACK_ROW_LENGTH, &row_length);
_glGetIntegerv(GL_UNPACK_IMAGE_HEIGHT, &image_height);
_glGetIntegerv(GL_UNPACK_SKIP_ROWS, &skip_rows);
_glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &skip_pixels);
_glGetIntegerv(GL_UNPACK_SKIP_IMAGES, &skip_images);
}
if (row_length <= 0) {
row_length = width;
}
size_t row_stride = (row_length*bits_per_pixel + 7)/8;
if ((bits_per_element == 1*8 ||
bits_per_element == 2*8 ||
bits_per_element == 4*8 ||
bits_per_element == 8*8) &&
(GLint)bits_per_element < alignment*8) {
row_stride = _align(row_stride, alignment);
}
if (image_height <= 0) {
image_height = height;
}
/* XXX: GL_UNPACK_IMAGE_HEIGHT and GL_UNPACK_SKIP_IMAGES should probably
* not be considered for pixel rectangles. */
size_t image_stride = image_height*row_stride;
size_t size = depth*image_stride;
size += (skip_pixels*bits_per_pixel + 7)/8;
size += skip_rows*row_stride;
size += skip_images*image_stride;
return size;
}
static inline size_t
_gl_image_size(GLenum format, GLenum type, GLsizei width, GLsizei height, GLsizei depth, GLboolean has_unpack_subimage)
{
unsigned bits_per_pixel = _gl_format_size(format, type);
GLint alignment = 4;
GLint row_length = 0;
GLint image_height = 0;
GLint skip_rows = 0;
GLint skip_pixels = 0;
GLint skip_images = 0;
_glGetIntegerv(GL_UNPACK_ALIGNMENT, &alignment);
if (has_unpack_subimage) {
_glGetIntegerv(GL_UNPACK_ROW_LENGTH, &row_length);
_glGetIntegerv(GL_UNPACK_IMAGE_HEIGHT, &image_height);
_glGetIntegerv(GL_UNPACK_SKIP_ROWS, &skip_rows);
_glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &skip_pixels);
_glGetIntegerv(GL_UNPACK_SKIP_IMAGES, &skip_images);
}
if (row_length <= 0) {
row_length = width;
}
size_t row_stride = (row_length*bits_per_pixel + 7)/8;
/*
* The OpenGL specification states that the unpack alignment should be
* ignored if the number of bits per element is not 1, 2, 4, or 8 times the
* number of bits in a GL ubyte, but the matter of fact is that the number
* of bits per element is always one of those.
*/
if (_is_pot(alignment)) {
row_stride = _align(row_stride, alignment);
}
if (image_height <= 0) {
image_height = height;
}
size_t image_stride = image_height*row_stride;
/*
* We can't just do
*
* size = depth*image_stride
*
* here as that could result in reading beyond the end of the buffer when
* selecting sub-rectangles via GL_UNPACK_SKIP_*.
*/
size_t size = (width*bits_per_pixel + 7)/8;
if (height > 1) {
size += (height - 1)*row_stride;
}
if (depth > 1) {
size += (depth - 1)*image_stride;
}
/* XXX: GL_UNPACK_IMAGE_HEIGHT and GL_UNPACK_SKIP_IMAGES should probably
* not be considered for pixel rectangles. */
size += (skip_pixels*bits_per_pixel + 7)/8;
size += skip_rows*row_stride;
size += skip_images*image_stride;
return size;
}
