/*
* Read R, G, B, A, RGB, L, or LA pixels.
*/
static void
read_rgba_pixels( struct gl_context *ctx,
GLint x, GLint y,
GLsizei width, GLsizei height,
GLenum format, GLenum type, GLvoid *pixels,
const struct gl_pixelstore_attrib *packing )
{
GLbitfield transferOps;
bool dst_is_integer, dst_is_luminance, needs_rebase;
int dst_stride, src_stride, rb_stride;
uint32_t dst_format, src_format;
GLubyte *dst, *map;
mesa_format rb_format;
bool needs_rgba;
void *rgba, *src;
bool src_is_uint = false;
uint8_t rebase_swizzle[4];
struct gl_framebuffer *fb = ctx->ReadBuffer;
struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
if (!rb)
return;
transferOps = get_readpixels_transfer_ops(ctx, rb->Format, format, type,
GL_FALSE);
/* Describe the dst format */
dst_is_integer = _mesa_is_enum_format_integer(format);
dst_stride = _mesa_image_row_stride(packing, width, format, type);
dst_format = _mesa_format_from_format_and_type(format, type);
dst_is_luminance = format == GL_LUMINANCE ||
format == GL_LUMINANCE_ALPHA ||
format == GL_LUMINANCE_INTEGER_EXT ||
format == GL_LUMINANCE_ALPHA_INTEGER_EXT;
dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
format, type, 0, 0);
/* Map the source render buffer */
ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
&map, &rb_stride);
if (!map) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
return;
}
rb_format = _mesa_get_srgb_format_linear(rb->Format);
/*
* Depending on the base formats involved in the conversion we might need to
* rebase some values, so for these formats we compute a rebase swizzle.
*/
if (rb->_BaseFormat == GL_LUMINANCE || rb->_BaseFormat == GL_INTENSITY) {
needs_rebase = true;
rebase_swizzle[0] = MESA_FORMAT_SWIZZLE_X;
rebase_swizzle[1] = MESA_FORMAT_SWIZZLE_ZERO;
rebase_swizzle[2] = MESA_FORMAT_SWIZZLE_ZERO;
rebase_swizzle[3] = MESA_FORMAT_SWIZZLE_ONE;
} else if (rb->_BaseFormat == GL_LUMINANCE_ALPHA) {
needs_rebase = true;
rebase_swizzle[0] = MESA_FORMAT_SWIZZLE_X;
rebase_swizzle[1] = MESA_FORMAT_SWIZZLE_ZERO;
rebase_swizzle[2] = MESA_FORMAT_SWIZZLE_ZERO;
rebase_swizzle[3] = MESA_FORMAT_SWIZZLE_W;
} else if (_mesa_get_format_base_format(rb_format) != rb->_BaseFormat) {
needs_rebase =
_mesa_compute_rgba2base2rgba_component_mapping(rb->_BaseFormat,
rebase_swizzle);
} else {
needs_rebase = false;
}
/* Since _mesa_format_convert does not handle transferOps we need to handle
* them before we call the function. This requires to convert to RGBA float
* first so we can call _mesa_apply_rgba_transfer_ops. If the dst format is
* integer transferOps do not apply.
*
* Converting to luminance also requires converting to RGBA first, so we can
* then compute luminance values as L=R+G+B. Notice that this is different
* from GetTexImage, where we compute L=R.
*/
assert(!transferOps || (transferOps && !dst_is_integer));
needs_rgba = transferOps || dst_is_luminance;
rgba = NULL;
if (needs_rgba) {
uint32_t rgba_format;
int rgba_stride;
bool need_convert;
/* Convert to RGBA float or int/uint depending on the type of the src */
if (dst_is_integer) {
src_is_uint = _mesa_is_format_unsigned(rb_format);
if (src_is_uint) {
rgba_format = RGBA32_UINT;
rgba_stride = width * 4 * sizeof(GLuint);
} else {
rgba_format = RGBA32_INT;
rgba_stride = width * 4 * sizeof(GLint);
}
} else {
rgba_format = RGBA32_FLOAT;
rgba_stride = width * 4 * sizeof(GLfloat);
}
/* If we are lucky and the dst format matches the RGBA format we need to
* convert to, then we can convert directly into the dst buffer and avoid
* the final conversion/copy from the rgba buffer to the dst buffer.
*/
if (dst_format == rgba_format) {
need_convert = false;
rgba = dst;
} else {
need_convert = true;
rgba = malloc(height * rgba_stride);
if (!rgba) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
goto done_unmap;
}
}
/* Convert to RGBA now */
_mesa_format_convert(rgba, rgba_format, rgba_stride,
map, rb_format, rb_stride,
width, height,
needs_rebase ? rebase_swizzle : NULL);
/* Handle transfer ops if necessary */
if (transferOps)
_mesa_apply_rgba_transfer_ops(ctx, transferOps, width * height, rgba);
/* If we had to rebase, we have already taken care of that */
needs_rebase = false;
/* If we were lucky and our RGBA conversion matches the dst format, then
* we are done.
*/
if (!need_convert)
goto done_swap;
/* Otherwise, we need to convert from RGBA to dst next */
src = rgba;
src_format = rgba_format;
src_stride = rgba_stride;
} else {
/* No RGBA conversion needed, convert directly to dst */
src = map;
src_format = rb_format;
src_stride = rb_stride;
}
/* Do the conversion.
*
* If the dst format is Luminance, we need to do the conversion by computing
* L=R+G+B values.
*/
if (!dst_is_luminance) {
_mesa_format_convert(dst, dst_format, dst_stride,
src, src_format, src_stride,
width, height,
needs_rebase ? rebase_swizzle : NULL);
} else if (!dst_is_integer) {
/* Compute float Luminance values from RGBA float */
int luminance_stride, luminance_bytes;
void *luminance;
uint32_t luminance_format;
luminance_stride = width * sizeof(GL_FLOAT);
if (format == GL_LUMINANCE_ALPHA)
luminance_stride *= 2;
luminance_bytes = height * luminance_stride;
luminance = malloc(luminance_bytes);
if (!luminance) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
free(rgba);
goto done_unmap;
}
_mesa_pack_luminance_from_rgba_float(width * height, src,
luminance, format, transferOps);
/* Convert from Luminance float to dst (this will hadle type conversion
* from float to the type of dst if necessary)
*/
luminance_format = _mesa_format_from_format_and_type(format, GL_FLOAT);
_mesa_format_convert(dst, dst_format, dst_stride,
luminance, luminance_format, luminance_stride,
width, height, NULL);
} else {
_mesa_pack_luminance_from_rgba_integer(width * height, src, !src_is_uint,
dst, format, type);
}
if (rgba)
free(rgba);
done_swap:
/* Handle byte swapping if required */
if (packing->SwapBytes) {
int components = _mesa_components_in_format(format);
GLint swapSize = _mesa_sizeof_packed_type(type);
if (swapSize == 2)
_mesa_swap2((GLushort *) dst, width * height * components);
else if (swapSize == 4)
_mesa_swap4((GLuint *) dst, width * height * components);
}
done_unmap:
ctx->Driver.UnmapRenderbuffer(ctx, rb);
}
static GLboolean
texstore_rgba(TEXSTORE_PARAMS)
{
void *tempImage = NULL, *tempRGBA = NULL;
int srcRowStride, img;
GLubyte *src, *dst;
uint32_t srcMesaFormat;
uint8_t rebaseSwizzle[4];
bool needRebase;
bool transferOpsDone = false;
/* We have to handle MESA_FORMAT_YCBCR manually because it is a special case
* and _mesa_format_convert does not support it. In this case the we only
* allow conversions between YCBCR formats and it is mostly a memcpy.
*/
if (dstFormat == MESA_FORMAT_YCBCR || dstFormat == MESA_FORMAT_YCBCR_REV) {
return _mesa_texstore_ycbcr(ctx, dims, baseInternalFormat,
dstFormat, dstRowStride, dstSlices,
srcWidth, srcHeight, srcDepth,
srcFormat, srcType, srcAddr,
srcPacking);
}
/* We have to deal with GL_COLOR_INDEX manually because
* _mesa_format_convert does not handle this format. So what we do here is
* convert it to RGBA ubyte first and then convert from that to dst as usual.
*/
if (srcFormat == GL_COLOR_INDEX) {
/* Notice that this will already handle byte swapping if necessary */
tempImage =
_mesa_unpack_color_index_to_rgba_ubyte(ctx, dims,
srcAddr, srcFormat, srcType,
srcWidth, srcHeight, srcDepth,
srcPacking,
ctx->_ImageTransferState);
if (!tempImage)
return GL_FALSE;
/* _mesa_unpack_color_index_to_rgba_ubyte has handled transferops
* if needed.
*/
transferOpsDone = true;
/* Now we only have to adjust our src info for a conversion from
* the RGBA ubyte and then we continue as usual.
*/
srcAddr = tempImage;
srcFormat = GL_RGBA;
srcType = GL_UNSIGNED_BYTE;
} else if (srcPacking->SwapBytes) {
/* We have to handle byte-swapping scenarios before calling
* _mesa_format_convert
*/
GLint swapSize = _mesa_sizeof_packed_type(srcType);
if (swapSize == 2 || swapSize == 4) {
int bytesPerPixel = _mesa_bytes_per_pixel(srcFormat, srcType);
int swapsPerPixel = bytesPerPixel / swapSize;
int elementCount = srcWidth * srcHeight * srcDepth;
assert(bytesPerPixel % swapSize == 0);
tempImage = malloc(elementCount * bytesPerPixel);
if (!tempImage)
return GL_FALSE;
if (swapSize == 2)
_mesa_swap2_copy(tempImage, (GLushort *) srcAddr,
elementCount * swapsPerPixel);
else
_mesa_swap4_copy(tempImage, (GLuint *) srcAddr,
elementCount * swapsPerPixel);
srcAddr = tempImage;
}
}
srcRowStride =
_mesa_image_row_stride(srcPacking, srcWidth, srcFormat, srcType);
srcMesaFormat = _mesa_format_from_format_and_type(srcFormat, srcType);
dstFormat = _mesa_get_srgb_format_linear(dstFormat);
/* If we have transferOps then we need to convert to RGBA float first,
then apply transferOps, then do the conversion to dst
*/
if (!transferOpsDone &&
_mesa_texstore_needs_transfer_ops(ctx, baseInternalFormat, dstFormat)) {
/* Allocate RGBA float image */
int elementCount = srcWidth * srcHeight * srcDepth;
tempRGBA = malloc(4 * elementCount * sizeof(float));
if (!tempRGBA) {
free(tempImage);
free(tempRGBA);
return GL_FALSE;
}
/* Convert from src to RGBA float */
src = (GLubyte *) srcAddr;
dst = (GLubyte *) tempRGBA;
for (img = 0; img < srcDepth; img++) {
_mesa_format_convert(dst, RGBA32_FLOAT, 4 * srcWidth * sizeof(float),
src, srcMesaFormat, srcRowStride,
srcWidth, srcHeight, NULL);
src += srcHeight * srcRowStride;
dst += srcHeight * 4 * srcWidth * sizeof(float);
}
/* Apply transferOps */
_mesa_apply_rgba_transfer_ops(ctx, ctx->_ImageTransferState, elementCount,
(float(*)[4]) tempRGBA);
/* Now we have to adjust our src info for a conversion from
* the RGBA float image and then we continue as usual.
*/
srcAddr = tempRGBA;
srcFormat = GL_RGBA;
srcType = GL_FLOAT;
srcRowStride = srcWidth * 4 * sizeof(float);
srcMesaFormat = RGBA32_FLOAT;
}
src = (GLubyte *)
_mesa_image_address(dims, srcPacking, srcAddr, srcWidth, srcHeight,
srcFormat, srcType, 0, 0, 0);
if (_mesa_get_format_base_format(dstFormat) != baseInternalFormat) {
needRebase =
_mesa_compute_rgba2base2rgba_component_mapping(baseInternalFormat,
rebaseSwizzle);
} else {
needRebase = false;
}
for (img = 0; img < srcDepth; img++) {
_mesa_format_convert(dstSlices[img], dstFormat, dstRowStride,
src, srcMesaFormat, srcRowStride,
srcWidth, srcHeight,
needRebase ? rebaseSwizzle : NULL);
src += srcHeight * srcRowStride;
}
free(tempImage);
free(tempRGBA);
return GL_TRUE;
}