static GLboolean
readpixels_can_use_memcpy(const struct gl_context *ctx, GLenum format, GLenum type,
const struct gl_pixelstore_attrib *packing)
{
struct gl_renderbuffer *rb =
_mesa_get_read_renderbuffer_for_format(ctx, format);
ASSERT(rb);
if (_mesa_readpixels_needs_slow_path(ctx, format, type, GL_FALSE)) {
return GL_FALSE;
}
/* The base internal format and the base Mesa format must match. */
if (rb->_BaseFormat != _mesa_get_format_base_format(rb->Format)) {
return GL_FALSE;
}
/* The Mesa format must match the input format and type. */
if (!_mesa_format_matches_format_and_type(rb->Format, format, type,
packing->SwapBytes)) {
return GL_FALSE;
}
return GL_TRUE;
}
/**
* Return true if memcpy cannot be used for ReadPixels.
*
* If uses_blit is true, the function returns true if a simple 3D engine blit
* cannot be used for ReadPixels packing.
*
* NOTE: This doesn't take swizzling and format conversions between
* the readbuffer and the pixel pack buffer into account.
*/
GLboolean
_mesa_readpixels_needs_slow_path(const struct gl_context *ctx, GLenum format,
GLenum type, GLboolean uses_blit)
{
struct gl_renderbuffer *rb =
_mesa_get_read_renderbuffer_for_format(ctx, format);
GLenum srcType;
ASSERT(rb);
/* There are different rules depending on the base format. */
switch (format) {
case GL_DEPTH_STENCIL:
return !_mesa_has_depthstencil_combined(ctx->ReadBuffer) ||
ctx->Pixel.DepthScale != 1.0f || ctx->Pixel.DepthBias != 0.0f ||
ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset ||
ctx->Pixel.MapStencilFlag;
case GL_DEPTH_COMPONENT:
return ctx->Pixel.DepthScale != 1.0f || ctx->Pixel.DepthBias != 0.0f;
case GL_STENCIL_INDEX:
return ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset ||
ctx->Pixel.MapStencilFlag;
default:
/* Color formats. */
if (need_rgb_to_luminance_conversion(rb->Format, format)) {
return GL_TRUE;
}
/* Conversion between signed and unsigned integers needs masking
* (it isn't just memcpy). */
srcType = _mesa_get_format_datatype(rb->Format);
if ((srcType == GL_INT &&
(type == GL_UNSIGNED_INT ||
type == GL_UNSIGNED_SHORT ||
type == GL_UNSIGNED_BYTE)) ||
(srcType == GL_UNSIGNED_INT &&
(type == GL_INT ||
type == GL_SHORT ||
type == GL_BYTE))) {
return GL_TRUE;
}
/* And finally, see if there are any transfer ops. */
return get_readpixels_transfer_ops(ctx, rb->Format, format, type,
uses_blit) != 0;
}
return GL_FALSE;
}
static GLboolean
readpixels_memcpy(struct gl_context *ctx,
GLint x, GLint y,
GLsizei width, GLsizei height,
GLenum format, GLenum type,
GLvoid *pixels,
const struct gl_pixelstore_attrib *packing)
{
struct gl_renderbuffer *rb =
_mesa_get_read_renderbuffer_for_format(ctx, format);
GLubyte *dst, *map;
int dstStride, stride, j, texelBytes;
/* Fail if memcpy cannot be used. */
if (!readpixels_can_use_memcpy(ctx, format, type, packing)) {
return GL_FALSE;
}
dstStride = _mesa_image_row_stride(packing, width, format, type);
dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
format, type, 0, 0);
ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
&map, &stride);
if (!map) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
return GL_TRUE; /* don't bother trying the slow path */
}
texelBytes = _mesa_get_format_bytes(rb->Format);
/* memcpy*/
for (j = 0; j < height; j++) {
memcpy(dst, map, width * texelBytes);
dst += dstStride;
map += stride;
}
ctx->Driver.UnmapRenderbuffer(ctx, rb);
return GL_TRUE;
}
/**
* Return true if memcpy cannot be used for ReadPixels.
*
* If uses_blit is true, the function returns true if a simple 3D engine blit
* cannot be used for ReadPixels packing.
*
* NOTE: This doesn't take swizzling and format conversions between
* the readbuffer and the pixel pack buffer into account.
*/
GLboolean
_mesa_readpixels_needs_slow_path(const struct gl_context *ctx, GLenum format,
GLenum type, GLboolean uses_blit)
{
struct gl_renderbuffer *rb =
_mesa_get_read_renderbuffer_for_format(ctx, format);
GLenum dstBaseFormat = _mesa_unpack_format_to_base_format(format);
assert(rb);
/* There are different rules depending on the base format. */
switch (format) {
case GL_DEPTH_STENCIL:
return !_mesa_has_depthstencil_combined(ctx->ReadBuffer) ||
ctx->Pixel.DepthScale != 1.0f || ctx->Pixel.DepthBias != 0.0f ||
ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset ||
ctx->Pixel.MapStencilFlag;
case GL_DEPTH_COMPONENT:
return ctx->Pixel.DepthScale != 1.0f || ctx->Pixel.DepthBias != 0.0f;
case GL_STENCIL_INDEX:
return ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset ||
ctx->Pixel.MapStencilFlag;
default:
/* Color formats. */
if (_mesa_need_rgb_to_luminance_conversion(rb->_BaseFormat,
dstBaseFormat)) {
return GL_TRUE;
}
/* And finally, see if there are any transfer ops. */
return _mesa_get_readpixels_transfer_ops(ctx, rb->Format, format, type,
uses_blit) != 0;
}
return GL_FALSE;
}
static boolean
needs_integer_signed_unsigned_conversion(const struct gl_context *ctx,
GLenum format, GLenum type)
{
struct gl_renderbuffer *rb =
_mesa_get_read_renderbuffer_for_format(ctx, format);
assert(rb);
GLenum srcType = _mesa_get_format_datatype(rb->Format);
if ((srcType == GL_INT &&
(type == GL_UNSIGNED_INT ||
type == GL_UNSIGNED_SHORT ||
type == GL_UNSIGNED_BYTE)) ||
(srcType == GL_UNSIGNED_INT &&
(type == GL_INT ||
type == GL_SHORT ||
type == GL_BYTE))) {
return TRUE;
}
return FALSE;
}
/**
* This uses a blit to copy the read buffer to a texture format which matches
* the format and type combo and then a fast read-back is done using memcpy.
* We can do arbitrary X/Y/Z/W/0/1 swizzling here as long as there is
* a format which matches the swizzling.
*
* If such a format isn't available, we fall back to _mesa_readpixels.
*
* NOTE: Some drivers use a blit to convert between tiled and linear
* texture layouts during texture uploads/downloads, so the blit
* we do here should be free in such cases.
*/
static void
st_readpixels(struct gl_context *ctx, GLint x, GLint y,
GLsizei width, GLsizei height,
GLenum format, GLenum type,
const struct gl_pixelstore_attrib *pack,
GLvoid *pixels)
{
struct st_context *st = st_context(ctx);
struct gl_renderbuffer *rb =
_mesa_get_read_renderbuffer_for_format(ctx, format);
struct st_renderbuffer *strb = st_renderbuffer(rb);
struct pipe_context *pipe = st->pipe;
struct pipe_screen *screen = pipe->screen;
struct pipe_resource *src;
struct pipe_resource *dst = NULL;
struct pipe_resource dst_templ;
enum pipe_format dst_format, src_format;
struct pipe_blit_info blit;
unsigned bind = PIPE_BIND_TRANSFER_READ;
struct pipe_transfer *tex_xfer;
ubyte *map = NULL;
/* Validate state (to be sure we have up-to-date framebuffer surfaces)
* and flush the bitmap cache prior to reading. */
st_validate_state(st);
st_flush_bitmap_cache(st);
if (!st->prefer_blit_based_texture_transfer) {
goto fallback;
}
/* This must be done after state validation. */
src = strb->texture;
/* XXX Fallback for depth-stencil formats due to an incomplete
* stencil blit implementation in some drivers. */
if (format == GL_DEPTH_STENCIL) {
goto fallback;
}
/* We are creating a texture of the size of the region being read back.
* Need to check for NPOT texture support. */
if (!screen->get_param(screen, PIPE_CAP_NPOT_TEXTURES) &&
(!util_is_power_of_two(width) ||
!util_is_power_of_two(height))) {
goto fallback;
}
/* If the base internal format and the texture format don't match, we have
* to use the slow path. */
if (rb->_BaseFormat !=
_mesa_get_format_base_format(rb->Format)) {
goto fallback;
}
/* See if the texture format already matches the format and type,
* in which case the memcpy-based fast path will likely be used and
* we don't have to blit. */
if (_mesa_format_matches_format_and_type(rb->Format, format,
type, pack->SwapBytes)) {
goto fallback;
}
if (_mesa_readpixels_needs_slow_path(ctx, format, type, GL_TRUE)) {
goto fallback;
}
/* Convert the source format to what is expected by ReadPixels
* and see if it's supported. */
src_format = util_format_linear(src->format);
src_format = util_format_luminance_to_red(src_format);
src_format = util_format_intensity_to_red(src_format);
if (!src_format ||
!screen->is_format_supported(screen, src_format, src->target,
src->nr_samples,
PIPE_BIND_SAMPLER_VIEW)) {
goto fallback;
}
if (format == GL_DEPTH_COMPONENT || format == GL_DEPTH_STENCIL)
bind |= PIPE_BIND_DEPTH_STENCIL;
else
bind |= PIPE_BIND_RENDER_TARGET;
/* Choose the destination format by finding the best match
* for the format+type combo. */
dst_format = st_choose_matching_format(screen, bind, format, type,
pack->SwapBytes);
if (dst_format == PIPE_FORMAT_NONE) {
goto fallback;
}
/* create the destination texture */
memset(&dst_templ, 0, sizeof(dst_templ));
dst_templ.target = PIPE_TEXTURE_2D;
dst_templ.format = dst_format;
dst_templ.bind = bind;
dst_templ.usage = PIPE_USAGE_STAGING;
st_gl_texture_dims_to_pipe_dims(GL_TEXTURE_2D, width, height, 1,
&dst_templ.width0, &dst_templ.height0,
&dst_templ.depth0, &dst_templ.array_size);
dst = screen->resource_create(screen, &dst_templ);
if (!dst) {
goto fallback;
}
memset(&blit, 0, sizeof(blit));
blit.src.resource = src;
blit.src.level = strb->surface->u.tex.level;
blit.src.format = src_format;
blit.dst.resource = dst;
blit.dst.level = 0;
blit.dst.format = dst->format;
blit.src.box.x = x;
blit.dst.box.x = 0;
blit.src.box.y = y;
blit.dst.box.y = 0;
blit.src.box.z = strb->surface->u.tex.first_layer;
blit.dst.box.z = 0;
blit.src.box.width = blit.dst.box.width = width;
blit.src.box.height = blit.dst.box.height = height;
blit.src.box.depth = blit.dst.box.depth = 1;
blit.mask = st_get_blit_mask(rb->_BaseFormat, format);
blit.filter = PIPE_TEX_FILTER_NEAREST;
blit.scissor_enable = FALSE;
if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
blit.src.box.y = rb->Height - blit.src.box.y;
blit.src.box.height = -blit.src.box.height;
}
/* blit */
st->pipe->blit(st->pipe, &blit);
/* map resources */
pixels = _mesa_map_pbo_dest(ctx, pack, pixels);
map = pipe_transfer_map_3d(pipe, dst, 0, PIPE_TRANSFER_READ,
0, 0, 0, width, height, 1, &tex_xfer);
if (!map) {
_mesa_unmap_pbo_dest(ctx, pack);
pipe_resource_reference(&dst, NULL);
goto fallback;
}
/* memcpy data into a user buffer */
{
const uint bytesPerRow = width * util_format_get_blocksize(dst_format);
GLuint row;
for (row = 0; row < (unsigned) height; row++) {
GLvoid *dest = _mesa_image_address3d(pack, pixels,
width, height, format,
type, 0, row, 0);
memcpy(dest, map, bytesPerRow);
map += tex_xfer->stride;
}
}
pipe_transfer_unmap(pipe, tex_xfer);
_mesa_unmap_pbo_dest(ctx, pack);
pipe_resource_reference(&dst, NULL);
return;
fallback:
_mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
}
void GLAPIENTRY
_mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
GLenum format, GLenum type, GLsizei bufSize,
GLvoid *pixels )
{
GLenum err = GL_NO_ERROR;
struct gl_renderbuffer *rb;
GET_CURRENT_CONTEXT(ctx);
FLUSH_VERTICES(ctx, 0);
FLUSH_CURRENT(ctx, 0);
if (MESA_VERBOSE & VERBOSE_API)
_mesa_debug(ctx, "glReadPixels(%d, %d, %s, %s, %p)\n",
width, height,
_mesa_lookup_enum_by_nr(format),
_mesa_lookup_enum_by_nr(type),
pixels);
if (width < 0 || height < 0) {
_mesa_error( ctx, GL_INVALID_VALUE,
"glReadPixels(width=%d height=%d)", width, height );
return;
}
if (ctx->NewState)
_mesa_update_state(ctx);
if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
_mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
"glReadPixels(incomplete framebuffer)" );
return;
}
rb = _mesa_get_read_renderbuffer_for_format(ctx, format);
if (rb == NULL) {
_mesa_error(ctx, GL_INVALID_OPERATION,
"glReadPixels(read buffer)");
return;
}
/* OpenGL ES 1.x and OpenGL ES 2.0 impose additional restrictions on the
* combinations of format and type that can be used.
*
* Technically, only two combinations are actually allowed:
* GL_RGBA/GL_UNSIGNED_BYTE, and some implementation-specific internal
* preferred combination. This code doesn't know what that preferred
* combination is, and Mesa can handle anything valid. Just work instead.
*/
if (_mesa_is_gles(ctx)) {
if (ctx->API == API_OPENGLES2 &&
_mesa_is_color_format(format) &&
_mesa_get_color_read_format(ctx) == format &&
_mesa_get_color_read_type(ctx) == type) {
err = GL_NO_ERROR;
} else if (ctx->Version < 30) {
err = _mesa_es_error_check_format_and_type(format, type, 2);
if (err == GL_NO_ERROR) {
if (type == GL_FLOAT || type == GL_HALF_FLOAT_OES) {
err = GL_INVALID_OPERATION;
}
}
} else {
err = read_pixels_es3_error_check(format, type, rb);
}
if (err == GL_NO_ERROR && (format == GL_DEPTH_COMPONENT
|| format == GL_DEPTH_STENCIL)) {
err = GL_INVALID_ENUM;
}
if (err != GL_NO_ERROR) {
_mesa_error(ctx, err, "glReadPixels(invalid format %s and/or type %s)",
_mesa_lookup_enum_by_nr(format),
_mesa_lookup_enum_by_nr(type));
return;
}
}
err = _mesa_error_check_format_and_type(ctx, format, type);
if (err != GL_NO_ERROR) {
_mesa_error(ctx, err, "glReadPixels(invalid format %s and/or type %s)",
_mesa_lookup_enum_by_nr(format),
_mesa_lookup_enum_by_nr(type));
return;
}
if (_mesa_is_user_fbo(ctx->ReadBuffer) &&
ctx->ReadBuffer->Visual.samples > 0) {
_mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(multisample FBO)");
return;
}
if (!_mesa_source_buffer_exists(ctx, format)) {
_mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(no readbuffer)");
return;
}
/* Check that the destination format and source buffer are both
* integer-valued or both non-integer-valued.
*/
if (ctx->Extensions.EXT_texture_integer && _mesa_is_color_format(format)) {
const struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
const GLboolean srcInteger = _mesa_is_format_integer_color(rb->Format);
const GLboolean dstInteger = _mesa_is_enum_format_integer(format);
if (dstInteger != srcInteger) {
_mesa_error(ctx, GL_INVALID_OPERATION,
"glReadPixels(integer / non-integer format mismatch");
return;
}
}
if (width == 0 || height == 0)
return; /* nothing to do */
if (!_mesa_validate_pbo_access(2, &ctx->Pack, width, height, 1,
format, type, bufSize, pixels)) {
if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {
_mesa_error(ctx, GL_INVALID_OPERATION,
"glReadPixels(out of bounds PBO access)");
} else {
_mesa_error(ctx, GL_INVALID_OPERATION,
"glReadnPixelsARB(out of bounds access:"
" bufSize (%d) is too small)", bufSize);
}
return;
}
if (_mesa_is_bufferobj(ctx->Pack.BufferObj) &&
_mesa_check_disallowed_mapping(ctx->Pack.BufferObj)) {
/* buffer is mapped - that's an error */
_mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(PBO is mapped)");
return;
}
ctx->Driver.ReadPixels(ctx, x, y, width, height,
format, type, &ctx->Pack, pixels);
}
