X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmesa%2Fstate_tracker%2Fst_cb_readpixels.c;h=d95a608d32e47bf72d02e737350864c54b0fe02c;hb=18ebf9e251cac6a0f898f4b7e159382f3c96b2b7;hp=67c3b9adbb9b62fcb322653025e3acda678999ed;hpb=b4a191e351ff1ac1cd27cd7e02d169958a78ca86;p=mesa.git diff --git a/src/mesa/state_tracker/st_cb_readpixels.c b/src/mesa/state_tracker/st_cb_readpixels.c index 67c3b9adbb9..d95a608d32e 100644 --- a/src/mesa/state_tracker/st_cb_readpixels.c +++ b/src/mesa/state_tracker/st_cb_readpixels.c @@ -1,6 +1,6 @@ /************************************************************************** * - * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas. + * Copyright 2007 VMware, Inc. * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a @@ -18,522 +18,215 @@ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. - * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR + * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * **************************************************************************/ - -/** - * glReadPixels interface to pipe - * - * \author Brian Paul - */ - - -#include "main/imports.h" -#include "main/bufferobj.h" -#include "main/context.h" #include "main/image.h" - -#include "pipe/p_context.h" -#include "pipe/p_defines.h" +#include "main/pbo.h" +#include "main/imports.h" +#include "main/readpix.h" +#include "main/enums.h" +#include "main/framebuffer.h" #include "util/u_inlines.h" -#include "util/u_tile.h" +#include "util/u_format.h" -#include "st_debug.h" -#include "st_context.h" +#include "st_cb_fbo.h" #include "st_atom.h" +#include "st_context.h" +#include "st_cb_bitmap.h" #include "st_cb_readpixels.h" -#include "st_cb_fbo.h" -#include "st_texture.h" -#include "st_inlines.h" - -/** - * Special case for reading stencil buffer. - * For color/depth we use get_tile(). For stencil, map the stencil buffer. - */ -void -st_read_stencil_pixels(GLcontext *ctx, GLint x, GLint y, - GLsizei width, GLsizei height, - GLenum format, GLenum type, - const struct gl_pixelstore_attrib *packing, - GLvoid *pixels) -{ - struct gl_framebuffer *fb = ctx->ReadBuffer; - struct pipe_context *pipe = ctx->st->pipe; - struct st_renderbuffer *strb = st_renderbuffer(fb->_StencilBuffer); - struct pipe_transfer *pt; - ubyte *stmap; - GLint j; - - if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) { - y = ctx->DrawBuffer->Height - y - height; - } - - /* Create a read transfer from the renderbuffer's texture */ - - pt = st_cond_flush_get_tex_transfer(st_context(ctx), strb->texture, - 0, 0, 0, - PIPE_TRANSFER_READ, x, y, - width, height); - - /* map the stencil buffer */ - stmap = pipe_transfer_map(pipe, pt); - - /* width should never be > MAX_WIDTH since we did clipping earlier */ - ASSERT(width <= MAX_WIDTH); - - /* process image row by row */ - for (j = 0; j < height; j++) { - GLvoid *dest; - GLstencil sValues[MAX_WIDTH]; - GLfloat zValues[MAX_WIDTH]; - GLint srcY; - - if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) { - srcY = height - j - 1; - } - else { - srcY = j; - } - - /* get stencil (and Z) values */ - switch (pt->resource->format) { - case PIPE_FORMAT_S8_USCALED: - { - const ubyte *src = stmap + srcY * pt->stride; - memcpy(sValues, src, width); - } - break; - case PIPE_FORMAT_Z24_UNORM_S8_USCALED: - if (format == GL_DEPTH_STENCIL) { - const uint *src = (uint *) (stmap + srcY * pt->stride); - const GLfloat scale = 1.0f / (0xffffff); - GLint k; - for (k = 0; k < width; k++) { - sValues[k] = src[k] >> 24; - zValues[k] = (src[k] & 0xffffff) * scale; - } - } - else { - const uint *src = (uint *) (stmap + srcY * pt->stride); - GLint k; - for (k = 0; k < width; k++) { - sValues[k] = src[k] >> 24; - } - } - break; - case PIPE_FORMAT_S8_USCALED_Z24_UNORM: - if (format == GL_DEPTH_STENCIL) { - const uint *src = (uint *) (stmap + srcY * pt->stride); - const GLfloat scale = 1.0f / (0xffffff); - GLint k; - for (k = 0; k < width; k++) { - sValues[k] = src[k] & 0xff; - zValues[k] = (src[k] >> 8) * scale; - } - } - else { - const uint *src = (uint *) (stmap + srcY * pt->stride); - GLint k; - for (k = 0; k < width; k++) { - sValues[k] = src[k] & 0xff; - } - } - break; - default: - assert(0); - } - - /* store */ - dest = _mesa_image_address2d(packing, pixels, width, height, - format, type, j, 0); - if (format == GL_DEPTH_STENCIL) { - _mesa_pack_depth_stencil_span(ctx, width, dest, - zValues, sValues, packing); - } - else { - _mesa_pack_stencil_span(ctx, width, type, dest, sValues, packing); - } - } - - /* unmap the stencil buffer */ - pipe_transfer_unmap(pipe, pt); - pipe->transfer_destroy(pipe, pt); -} - - -/** - * Return renderbuffer to use for reading color pixels for glRead/CopyPixel - * commands. - */ -struct st_renderbuffer * -st_get_color_read_renderbuffer(GLcontext *ctx) -{ - struct gl_framebuffer *fb = ctx->ReadBuffer; - struct st_renderbuffer *strb = - st_renderbuffer(fb->_ColorReadBuffer); - - return strb; -} - - -/** - * Try to do glReadPixels in a fast manner for common cases. - * \return GL_TRUE for success, GL_FALSE for failure - */ -static GLboolean -st_fast_readpixels(GLcontext *ctx, struct st_renderbuffer *strb, - GLint x, GLint y, GLsizei width, GLsizei height, - GLenum format, GLenum type, - const struct gl_pixelstore_attrib *pack, - GLvoid *dest) -{ - enum combination { - A8R8G8B8_UNORM_TO_RGBA_UBYTE, - A8R8G8B8_UNORM_TO_RGB_UBYTE, - A8R8G8B8_UNORM_TO_BGRA_UINT - } combo; - - if (ctx->_ImageTransferState) - return GL_FALSE; - - if (strb->format == PIPE_FORMAT_B8G8R8A8_UNORM && - format == GL_RGBA && type == GL_UNSIGNED_BYTE) { - combo = A8R8G8B8_UNORM_TO_RGBA_UBYTE; - } - else if (strb->format == PIPE_FORMAT_B8G8R8A8_UNORM && - format == GL_RGB && type == GL_UNSIGNED_BYTE) { - combo = A8R8G8B8_UNORM_TO_RGB_UBYTE; - } - else if (strb->format == PIPE_FORMAT_B8G8R8A8_UNORM && - format == GL_BGRA && type == GL_UNSIGNED_INT_8_8_8_8_REV) { - combo = A8R8G8B8_UNORM_TO_BGRA_UINT; - } - else { - return GL_FALSE; - } - - /*printf("st_fast_readpixels combo %d\n", (GLint) combo);*/ - - { - struct pipe_context *pipe = ctx->st->pipe; - struct pipe_transfer *trans; - const GLubyte *map; - GLubyte *dst; - GLint row, col, dy, dstStride; - - if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) { - /* convert GL Y to Gallium Y */ - y = strb->texture->height0 - y - height; - } - - trans = st_cond_flush_get_tex_transfer(st_context(ctx), strb->texture, - 0, 0, 0, - PIPE_TRANSFER_READ, x, y, - width, height); - if (!trans) { - return GL_FALSE; - } - - map = pipe_transfer_map(pipe, trans); - if (!map) { - pipe->transfer_destroy(pipe, trans); - return GL_FALSE; - } - - /* We always write to the user/dest buffer from low addr to high addr - * but the read order depends on renderbuffer orientation - */ - if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) { - /* read source rows from bottom to top */ - y = height - 1; - dy = -1; - } - else { - /* read source rows from top to bottom */ - y = 0; - dy = 1; - } - - dst = _mesa_image_address2d(pack, dest, width, height, - format, type, 0, 0); - dstStride = _mesa_image_row_stride(pack, width, format, type); - - switch (combo) { - case A8R8G8B8_UNORM_TO_RGBA_UBYTE: - for (row = 0; row < height; row++) { - const GLubyte *src = map + y * trans->stride; - for (col = 0; col < width; col++) { - GLuint pixel = ((GLuint *) src)[col]; - dst[col*4+0] = (pixel >> 16) & 0xff; - dst[col*4+1] = (pixel >> 8) & 0xff; - dst[col*4+2] = (pixel >> 0) & 0xff; - dst[col*4+3] = (pixel >> 24) & 0xff; - } - dst += dstStride; - y += dy; - } - break; - case A8R8G8B8_UNORM_TO_RGB_UBYTE: - for (row = 0; row < height; row++) { - const GLubyte *src = map + y * trans->stride; - for (col = 0; col < width; col++) { - GLuint pixel = ((GLuint *) src)[col]; - dst[col*3+0] = (pixel >> 16) & 0xff; - dst[col*3+1] = (pixel >> 8) & 0xff; - dst[col*3+2] = (pixel >> 0) & 0xff; - } - dst += dstStride; - y += dy; - } - break; - case A8R8G8B8_UNORM_TO_BGRA_UINT: - for (row = 0; row < height; row++) { - const GLubyte *src = map + y * trans->stride; - memcpy(dst, src, 4 * width); - dst += dstStride; - y += dy; - } - break; - default: - ; /* nothing */ - } - - pipe_transfer_unmap(pipe, trans); - pipe->transfer_destroy(pipe, trans); - } - - return GL_TRUE; -} +#include "state_tracker/st_cb_texture.h" +#include "state_tracker/st_format.h" +#include "state_tracker/st_texture.h" /** - * Do glReadPixels by getting rows from the framebuffer transfer with - * get_tile(). Convert to requested format/type with Mesa image routines. - * Image transfer ops are done in software too. + * 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(GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, +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 *dest) + GLvoid *pixels) { - struct pipe_context *pipe = ctx->st->pipe; - GLfloat temp[MAX_WIDTH][4]; - const GLbitfield transferOps = ctx->_ImageTransferState; - GLsizei i, j; - GLint yStep, dfStride; - GLfloat *df; - struct st_renderbuffer *strb; - struct gl_pixelstore_attrib clippedPacking = *pack; - struct pipe_transfer *trans; - - assert(ctx->ReadBuffer->Width > 0); - - /* XXX convolution not done yet */ - assert((transferOps & IMAGE_CONVOLUTION_BIT) == 0); - - st_validate_state(ctx->st); - - /* Do all needed clipping here, so that we can forget about it later */ - if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) { - /* The ReadPixels transfer is totally outside the window bounds */ - return; - } - - dest = _mesa_map_pbo_dest(ctx, &clippedPacking, dest); - if (!dest) - return; - - st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL); - - if (format == GL_STENCIL_INDEX || - format == GL_DEPTH_STENCIL) { - st_read_stencil_pixels(ctx, x, y, width, height, - format, type, pack, dest); - return; - } - else if (format == GL_DEPTH_COMPONENT) { - strb = st_renderbuffer(ctx->ReadBuffer->_DepthBuffer); - } - else { - /* Read color buffer */ - strb = st_get_color_read_renderbuffer(ctx); - } - - if (!strb) - return; - - /* try a fast-path readpixels before anything else */ - if (st_fast_readpixels(ctx, strb, x, y, width, height, - format, type, pack, dest)) { - /* success! */ - _mesa_unmap_pbo_dest(ctx, &clippedPacking); - return; - } - - if (format == GL_RGBA && type == GL_FLOAT) { - /* write tile(row) directly into user's buffer */ - df = (GLfloat *) _mesa_image_address2d(&clippedPacking, dest, width, - height, format, type, 0, 0); - dfStride = width * 4; - } - else { - /* write tile(row) into temp row buffer */ - df = (GLfloat *) temp; - dfStride = 0; - } + 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(st, 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) { - /* convert GL Y to Gallium Y */ - y = strb->Base.Height - y - height; + blit.src.box.y = rb->Height - blit.src.box.y; + blit.src.box.height = -blit.src.box.height; } - /* Create a read transfer from the renderbuffer's texture */ - trans = st_cond_flush_get_tex_transfer(st_context(ctx), strb->texture, - 0, 0, 0, - PIPE_TRANSFER_READ, x, y, - width, height); + /* blit */ + st->pipe->blit(st->pipe, &blit); - /* determine bottom-to-top vs. top-to-bottom order */ - if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) { - y = height - 1; - yStep = -1; - } - else { - y = 0; - yStep = 1; - } + /* map resources */ + pixels = _mesa_map_pbo_dest(ctx, pack, pixels); - if (ST_DEBUG & DEBUG_FALLBACK) - debug_printf("%s: fallback processing\n", __FUNCTION__); + 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; + } - /* - * Copy pixels from pipe_transfer to user memory - */ + /* memcpy data into a user buffer */ { - /* dest of first pixel in client memory */ - GLubyte *dst = _mesa_image_address2d(&clippedPacking, dest, width, - height, format, type, 0, 0); - /* dest row stride */ - const GLint dstStride = _mesa_image_row_stride(&clippedPacking, width, - format, type); + const uint bytesPerRow = width * util_format_get_blocksize(dst_format); + GLuint row; - if (trans->resource->format == PIPE_FORMAT_Z24_UNORM_S8_USCALED || - trans->resource->format == PIPE_FORMAT_Z24X8_UNORM) { - if (format == GL_DEPTH_COMPONENT) { - for (i = 0; i < height; i++) { - GLuint ztemp[MAX_WIDTH]; - GLfloat zfloat[MAX_WIDTH]; - const double scale = 1.0 / ((1 << 24) - 1); - pipe_get_tile_raw(pipe, trans, 0, y, width, 1, ztemp, 0); - y += yStep; - for (j = 0; j < width; j++) { - zfloat[j] = (float) (scale * (ztemp[j] & 0xffffff)); - } - _mesa_pack_depth_span(ctx, width, dst, type, - zfloat, &clippedPacking); - dst += dstStride; - } - } - else { - /* XXX: unreachable code -- should be before st_read_stencil_pixels */ - assert(format == GL_DEPTH_STENCIL_EXT); - for (i = 0; i < height; i++) { - GLuint *zshort = (GLuint *)dst; - pipe_get_tile_raw(pipe, trans, 0, y, width, 1, dst, 0); - y += yStep; - /* Reverse into 24/8 */ - for (j = 0; j < width; j++) { - zshort[j] = (zshort[j] << 8) | (zshort[j] >> 24); - } - dst += dstStride; - } - } - } - else if (trans->resource->format == PIPE_FORMAT_S8_USCALED_Z24_UNORM || - trans->resource->format == PIPE_FORMAT_X8Z24_UNORM) { - if (format == GL_DEPTH_COMPONENT) { - for (i = 0; i < height; i++) { - GLuint ztemp[MAX_WIDTH]; - GLfloat zfloat[MAX_WIDTH]; - const double scale = 1.0 / ((1 << 24) - 1); - pipe_get_tile_raw(pipe, trans, 0, y, width, 1, ztemp, 0); - y += yStep; - for (j = 0; j < width; j++) { - zfloat[j] = (float) (scale * ((ztemp[j] >> 8) & 0xffffff)); - } - _mesa_pack_depth_span(ctx, width, dst, type, - zfloat, &clippedPacking); - dst += dstStride; - } - } - else { - /* XXX: unreachable code -- should be before st_read_stencil_pixels */ - assert(format == GL_DEPTH_STENCIL_EXT); - for (i = 0; i < height; i++) { - pipe_get_tile_raw(pipe, trans, 0, y, width, 1, dst, 0); - y += yStep; - dst += dstStride; - } - } - } - else if (trans->resource->format == PIPE_FORMAT_Z16_UNORM) { - for (i = 0; i < height; i++) { - GLushort ztemp[MAX_WIDTH]; - GLfloat zfloat[MAX_WIDTH]; - const double scale = 1.0 / 0xffff; - pipe_get_tile_raw(pipe, trans, 0, y, width, 1, ztemp, 0); - y += yStep; - for (j = 0; j < width; j++) { - zfloat[j] = (float) (scale * ztemp[j]); - } - _mesa_pack_depth_span(ctx, width, dst, type, - zfloat, &clippedPacking); - dst += dstStride; - } - } - else if (trans->resource->format == PIPE_FORMAT_Z32_UNORM) { - for (i = 0; i < height; i++) { - GLuint ztemp[MAX_WIDTH]; - GLfloat zfloat[MAX_WIDTH]; - const double scale = 1.0 / 0xffffffff; - pipe_get_tile_raw(pipe, trans, 0, y, width, 1, ztemp, 0); - y += yStep; - for (j = 0; j < width; j++) { - zfloat[j] = (float) (scale * ztemp[j]); - } - _mesa_pack_depth_span(ctx, width, dst, type, - zfloat, &clippedPacking); - dst += dstStride; - } - } - else { - /* RGBA format */ - /* Do a row at a time to flip image data vertically */ - for (i = 0; i < height; i++) { - pipe_get_tile_rgba(pipe, trans, 0, y, width, 1, df); - y += yStep; - df += dfStride; - if (!dfStride) { - _mesa_pack_rgba_span_float(ctx, width, temp, format, type, dst, - &clippedPacking, transferOps); - dst += dstStride; - } - } + 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_destroy(pipe, trans); + pipe_transfer_unmap(pipe, tex_xfer); + _mesa_unmap_pbo_dest(ctx, pack); + pipe_resource_reference(&dst, NULL); + return; - _mesa_unmap_pbo_dest(ctx, &clippedPacking); +fallback: + _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels); } - void st_init_readpixels_functions(struct dd_function_table *functions) { functions->ReadPixels = st_readpixels;