/*
* 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);
}
/**
* Get an uncompressed color texture image.
*/
static void
get_tex_rgba_uncompressed(struct gl_context *ctx, GLuint dimensions,
GLenum format, GLenum type, GLvoid *pixels,
struct gl_texture_image *texImage,
GLbitfield transferOps)
{
/* don't want to apply sRGB -> RGB conversion here so override the format */
const gl_format texFormat =
_mesa_get_srgb_format_linear(texImage->TexFormat);
const GLuint width = texImage->Width;
const GLenum destBaseFormat = _mesa_base_tex_format(ctx, format);
GLenum rebaseFormat = GL_NONE;
GLuint height = texImage->Height;
GLuint depth = texImage->Depth;
GLuint img, row;
GLfloat (*rgba)[4];
GLuint (*rgba_uint)[4];
GLboolean tex_is_integer = _mesa_is_format_integer_color(texImage->TexFormat);
GLboolean tex_is_uint = _mesa_is_format_unsigned(texImage->TexFormat);
/* Allocate buffer for one row of texels */
rgba = (GLfloat (*)[4]) malloc(4 * width * sizeof(GLfloat));
rgba_uint = (GLuint (*)[4]) rgba;
if (!rgba) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glGetTexImage()");
return;
}
if (texImage->TexObject->Target == GL_TEXTURE_1D_ARRAY) {
depth = height;
height = 1;
}
if (texImage->_BaseFormat == GL_LUMINANCE ||
texImage->_BaseFormat == GL_INTENSITY ||
texImage->_BaseFormat == GL_LUMINANCE_ALPHA) {
/* If a luminance (or intensity) texture is read back as RGB(A), the
* returned value should be (L,0,0,1), not (L,L,L,1). Set rebaseFormat
* here to get G=B=0.
*/
rebaseFormat = texImage->_BaseFormat;
}
else if ((texImage->_BaseFormat == GL_RGBA ||
texImage->_BaseFormat == GL_RGB ||
texImage->_BaseFormat == GL_RG) &&
(destBaseFormat == GL_LUMINANCE ||
destBaseFormat == GL_LUMINANCE_ALPHA ||
destBaseFormat == GL_LUMINANCE_INTEGER_EXT ||
destBaseFormat == GL_LUMINANCE_ALPHA_INTEGER_EXT)) {
/* If we're reading back an RGB(A) texture as luminance then we need
* to return L=tex(R). Note, that's different from glReadPixels which
* returns L=R+G+B.
*/
rebaseFormat = GL_LUMINANCE_ALPHA; /* this covers GL_LUMINANCE too */
}
for (img = 0; img < depth; img++) {
GLubyte *srcMap;
GLint rowstride;
/* map src texture buffer */
ctx->Driver.MapTextureImage(ctx, texImage, img,
0, 0, width, height, GL_MAP_READ_BIT,
&srcMap, &rowstride);
if (srcMap) {
for (row = 0; row < height; row++) {
const GLubyte *src = srcMap + row * rowstride;
void *dest = _mesa_image_address(dimensions, &ctx->Pack, pixels,
width, height, format, type,
img, row, 0);
if (tex_is_integer) {
_mesa_unpack_uint_rgba_row(texFormat, width, src, rgba_uint);
if (rebaseFormat)
_mesa_rebase_rgba_uint(width, rgba_uint, rebaseFormat);
if (tex_is_uint) {
_mesa_pack_rgba_span_from_uints(ctx, width,
(GLuint (*)[4]) rgba_uint,
format, type, dest);
} else {
_mesa_pack_rgba_span_from_ints(ctx, width,
(GLint (*)[4]) rgba_uint,
format, type, dest);
}
} else {
_mesa_unpack_rgba_row(texFormat, width, src, rgba);
if (rebaseFormat)
_mesa_rebase_rgba_float(width, rgba, rebaseFormat);
_mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba,
format, type, dest,
&ctx->Pack, transferOps);
}
}
/* Unmap the src texture buffer */
ctx->Driver.UnmapTextureImage(ctx, texImage, img);
}
else {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glGetTexImage");
break;
}
}
free(rgba);
}
