diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_wm_emit.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_wm_emit.c b/src/mesa/drivers/dri/i965/brw_wm_emit.c index 2d1d011e553..05e464d4b61 100644 --- a/src/mesa/drivers/dri/i965/brw_wm_emit.c +++ b/src/mesa/drivers/dri/i965/brw_wm_emit.c @@ -62,7 +62,13 @@ static INLINE struct brw_reg sechalf( struct brw_reg reg ) } -/* Payload R0: +/** + * Computes the screen-space x,y position of the pixels. + * + * This will be used by emit_delta_xy() or emit_wpos_xy() for + * interpolation of attributes.. + * + * Payload R0: * * R0.0 -- pixel mask, one bit for each of 4 pixels in 4 tiles, * corresponding to each of the 16 execution channels. @@ -77,7 +83,6 @@ static INLINE struct brw_reg sechalf( struct brw_reg reg ) * R1.7 -- ? * R1.8 -- ? */ - void emit_pixel_xy(struct brw_wm_compile *c, const struct brw_reg *dst, GLuint mask) @@ -117,7 +122,14 @@ void emit_pixel_xy(struct brw_wm_compile *c, brw_pop_insn_state(p); } - +/** + * Computes the screen-space x,y distance of the pixels from the start + * vertex. + * + * This will be used in linterp or pinterp with the start vertex value + * and the Cx, Cy, and C0 coefficients passed in from the setup engine + * to produce interpolated attribute values. + */ void emit_delta_xy(struct brw_compile *p, const struct brw_reg *dst, GLuint mask, @@ -131,7 +143,7 @@ void emit_delta_xy(struct brw_compile *p, assert(mask == WRITEMASK_XY); /* Calc delta X,Y by subtracting origin in r1 from the pixel - * centers. + * centers produced by emit_pixel_xy(). */ brw_ADD(p, dst[0], @@ -143,6 +155,9 @@ void emit_delta_xy(struct brw_compile *p, negate(suboffset(r1,1))); } +/** + * Computes the pixel offset from the window origin for gl_FragCoord(). + */ void emit_wpos_xy(struct brw_wm_compile *c, const struct brw_reg *dst, GLuint mask, @@ -150,9 +165,6 @@ void emit_wpos_xy(struct brw_wm_compile *c, { struct brw_compile *p = &c->func; - /* Calculate the pixel offset from window bottom left into destination - * X and Y channels. - */ if (mask & WRITEMASK_X) { if (c->fp->program.PixelCenterInteger) { /* X' = X */ |