diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_meta_util.c | 224 |
1 files changed, 163 insertions, 61 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_meta_util.c b/src/mesa/drivers/dri/i965/brw_meta_util.c index a3b060413e5..b250d8a8146 100644 --- a/src/mesa/drivers/dri/i965/brw_meta_util.c +++ b/src/mesa/drivers/dri/i965/brw_meta_util.c @@ -41,65 +41,111 @@ fixup_mirroring(bool *mirror, float *coord0, float *coord1) } /** - * Adjust {src,dst}_x{0,1} to account for clipping and scissoring of - * destination coordinates. + * Compute the number of pixels to clip for each side of a rect * - * Return true if there is still blitting to do, false if all pixels got - * rejected by the clip and/or scissor. + * \param x0 The rect's left coordinate + * \param y0 The rect's bottom coordinate + * \param x1 The rect's right coordinate + * \param y1 The rect's top coordinate + * \param min_x The clipping region's left coordinate + * \param min_y The clipping region's bottom coordinate + * \param max_x The clipping region's right coordinate + * \param max_y The clipping region's top coordinate + * \param clipped_x0 The number of pixels to clip from the left side + * \param clipped_y0 The number of pixels to clip from the bottom side + * \param clipped_x1 The number of pixels to clip from the right side + * \param clipped_y1 The number of pixels to clip from the top side * - * For clarity, the nomenclature of this function assumes we are clipping and - * scissoring the X coordinate; the exact same logic applies for Y - * coordinates. - * - * Note: this function may also be used to account for clipping of source - * coordinates, by swapping the roles of src and dst. + * \return false if we clip everything away, true otherwise */ static inline bool -clip_or_scissor(bool mirror, - GLfloat *src_x0, GLfloat *src_x1, - GLfloat *dst_x0, GLfloat *dst_x1, - GLfloat fb_xmin, GLfloat fb_xmax) +compute_pixels_clipped(float x0, float y0, float x1, float y1, + float min_x, float min_y, float max_x, float max_y, + float *clipped_x0, float *clipped_y0, float *clipped_x1, float *clipped_y1) { - float scale = (float) (*src_x1 - *src_x0) / (*dst_x1 - *dst_x0); - /* If we are going to scissor everything away, stop. */ - if (!(fb_xmin < fb_xmax && - *dst_x0 < fb_xmax && - fb_xmin < *dst_x1 && - *dst_x0 < *dst_x1)) { + /* If we are going to clip everything away, stop. */ + if (!(min_x <= max_x && + min_y <= max_y && + x0 <= max_x && + y0 <= max_y && + min_x <= x1 && + min_y <= y1 && + x0 <= x1 && + y0 <= y1)) { return false; } - /* Clip the destination rectangle, and keep track of how many pixels we - * clipped off of the left and right sides of it. - */ - int pixels_clipped_left = 0; - int pixels_clipped_right = 0; - if (*dst_x0 < fb_xmin) { - pixels_clipped_left = fb_xmin - *dst_x0; - *dst_x0 = fb_xmin; - } - if (fb_xmax < *dst_x1) { - pixels_clipped_right = *dst_x1 - fb_xmax; - *dst_x1 = fb_xmax; - } + if (x0 < min_x) + *clipped_x0 = min_x - x0; + else + *clipped_x0 = 0; + if (max_x < x1) + *clipped_x1 = x1 - max_x; + else + *clipped_x1 = 0; - /* If we are mirrored, then before applying pixels_clipped_{left,right} to - * the source coordinates, we need to flip them to account for the - * mirroring. - */ - if (mirror) { - int tmp = pixels_clipped_left; - pixels_clipped_left = pixels_clipped_right; - pixels_clipped_right = tmp; - } + if (y0 < min_y) + *clipped_y0 = min_y - y0; + else + *clipped_y0 = 0; + if (max_y < y1) + *clipped_y1 = y1 - max_y; + else + *clipped_y1 = 0; + + return true; +} - /* Adjust the source rectangle to remove the pixels corresponding to those - * that were clipped/scissored out of the destination rectangle. +/** + * Clips a coordinate (left, right, top or bottom) for the src or dst rect + * (whichever requires the largest clip) and adjusts the coordinate + * for the other rect accordingly. + * + * \param mirror true if mirroring is required + * \param src the source rect coordinate (for example srcX0) + * \param dst0 the dst rect coordinate (for example dstX0) + * \param dst1 the opposite dst rect coordinate (for example dstX1) + * \param clipped_src0 number of pixels to clip from the src coordinate + * \param clipped_dst0 number of pixels to clip from the dst coordinate + * \param clipped_dst1 number of pixels to clip from the opposite dst coordinate + * \param scale the src vs dst scale involved for that coordinate + * \param isLeftOrBottom true if we are clipping the left or bottom sides + * of the rect. + */ +static inline void +clip_coordinates(bool mirror, + float *src, float *dst0, float *dst1, + float clipped_src0, + float clipped_dst0, + float clipped_dst1, + float scale, + bool isLeftOrBottom) +{ + /* When clipping we need to add or subtract pixels from the original + * coordinates depending on whether we are acting on the left/bottom + * or right/top sides of the rect respectively. We assume we have to + * add them in the code below, and multiply by -1 when we should + * subtract. */ - *src_x0 += pixels_clipped_left * scale; - *src_x1 -= pixels_clipped_right * scale; + int mult = isLeftOrBottom ? 1 : -1; - return true; + if (!mirror) { + if (clipped_src0 >= clipped_dst0 * scale) { + *src += clipped_src0 * mult; + *dst0 += clipped_src0 / scale * mult; + } else { + *dst0 += clipped_dst0 * mult; + *src += clipped_dst0 * scale * mult; + } + } else { + if (clipped_src0 >= clipped_dst1 * scale) { + *src += clipped_src0 * mult; + *dst1 -= clipped_src0 / scale * mult; + } else { + *dst1 -= clipped_dst1 * mult; + *src += clipped_dst1 * scale * mult; + } + } } bool @@ -121,23 +167,79 @@ brw_meta_mirror_clip_and_scissor(const struct gl_context *ctx, fixup_mirroring(mirror_y, srcY0, srcY1); fixup_mirroring(mirror_y, dstY0, dstY1); - /* If the destination rectangle needs to be clipped or scissored, do so. */ - if (!(clip_or_scissor(*mirror_x, srcX0, srcX1, dstX0, dstX1, - draw_fb->_Xmin, draw_fb->_Xmax) && - clip_or_scissor(*mirror_y, srcY0, srcY1, dstY0, dstY1, - draw_fb->_Ymin, draw_fb->_Ymax))) { - /* Everything got clipped/scissored away, so the blit was successful. */ + /* Compute number of pixels to clip for each side of both rects. Return + * early if we are going to clip everything away. + */ + float clip_src_x0; + float clip_src_x1; + float clip_src_y0; + float clip_src_y1; + float clip_dst_x0; + float clip_dst_x1; + float clip_dst_y0; + float clip_dst_y1; + + if (!compute_pixels_clipped(*srcX0, *srcY0, *srcX1, *srcY1, + 0, 0, read_fb->Width, read_fb->Height, + &clip_src_x0, &clip_src_y0, &clip_src_x1, &clip_src_y1)) return true; - } - /* If the source rectangle needs to be clipped or scissored, do so. */ - if (!(clip_or_scissor(*mirror_x, dstX0, dstX1, srcX0, srcX1, - 0, read_fb->Width) && - clip_or_scissor(*mirror_y, dstY0, dstY1, srcY0, srcY1, - 0, read_fb->Height))) { - /* Everything got clipped/scissored away, so the blit was successful. */ + if (!compute_pixels_clipped(*dstX0, *dstY0, *dstX1, *dstY1, + draw_fb->_Xmin, draw_fb->_Ymin, draw_fb->_Xmax, draw_fb->_Ymax, + &clip_dst_x0, &clip_dst_y0, &clip_dst_x1, &clip_dst_y1)) return true; - } + + /* When clipping any of the two rects we need to adjust the coordinates in + * the other rect considering the scaling factor involved. To obtain the best + * precision we want to make sure that we only clip once per side to avoid + * accumulating errors due to the scaling adjustment. + * + * For example, if srcX0 and dstX0 need both to be clipped we want to avoid + * the situation where we clip srcX0 first, then adjust dstX0 accordingly + * but then we realize that the resulting dstX0 still needs to be clipped, + * so we clip dstX0 and adjust srcX0 again. Because we are applying scaling + * factors to adjust the coordinates in each clipping pass we lose some + * precision and that can affect the results of the blorp blit operation + * slightly. What we want to do here is detect the rect that we should + * clip first for each side so that when we adjust the other rect we ensure + * the resulting coordinate does not need to be clipped again. + * + * The code below implements this by comparing the number of pixels that + * we need to clip for each side of both rects considering the scales + * involved. For example, clip_src_x0 represents the number of pixels to be + * clipped for the src rect's left side, so if clip_src_x0 = 5, + * clip_dst_x0 = 4 and scaleX = 2 it means that we are clipping more from + * the dst rect so we should clip dstX0 only and adjust srcX0. This is + * because clipping 4 pixels in the dst is equivalent to clipping + * 4 * 2 = 8 > 5 in the src. + */ + + float scaleX = (float) (*srcX1 - *srcX0) / (*dstX1 - *dstX0); + float scaleY = (float) (*srcY1 - *srcY0) / (*dstY1 - *dstY0); + + /* Clip left side */ + clip_coordinates(*mirror_x, + srcX0, dstX0, dstX1, + clip_src_x0, clip_dst_x0, clip_dst_x1, + scaleX, true); + + /* Clip right side */ + clip_coordinates(*mirror_x, + srcX1, dstX1, dstX0, + clip_src_x1, clip_dst_x1, clip_dst_x0, + scaleX, false); + + /* Clip bottom side */ + clip_coordinates(*mirror_y, + srcY0, dstY0, dstY1, + clip_src_y0, clip_dst_y0, clip_dst_y1, + scaleY, true); + + /* Clip top side */ + clip_coordinates(*mirror_y, + srcY1, dstY1, dstY0, + clip_src_y1, clip_dst_y1, clip_dst_y0, + scaleY, false); /* Account for the fact that in the system framebuffer, the origin is at * the lower left. |