diff options
| -rw-r--r-- | src/mesa/main/ffvertex_prog.c | 44 |
1 files changed, 31 insertions, 13 deletions
diff --git a/src/mesa/main/ffvertex_prog.c b/src/mesa/main/ffvertex_prog.c index d71e0c00fdb..e6c7c1040fa 100644 --- a/src/mesa/main/ffvertex_prog.c +++ b/src/mesa/main/ffvertex_prog.c @@ -969,25 +969,29 @@ static struct ureg calculate_light_attenuation( struct tnl_program *p, } +/** + * Compute: + * lit.y = MAX(0, dots.x) + * lit.z = SLT(0, dots.x) + */ static void emit_degenerate_lit( struct tnl_program *p, struct ureg lit, struct ureg dots ) { - struct ureg id = get_identity_param(p); - - /* 1, 0, 0, 1 + struct ureg id = get_identity_param(p); /* id = {0,0,0,1} */ + + /* Note that lit.x & lit.w will not be examined. Note also that + * dots.xyzw == dots.xxxx. */ - emit_op1(p, OPCODE_MOV, lit, 0, swizzle(id, Z, X, X, Z)); - /* 1, MAX2(in[0], 0), 0, 1 + /* MAX lit, id, dots; */ - emit_op2(p, OPCODE_MAX, lit, WRITEMASK_Y, lit, swizzle1(dots, X)); + emit_op2(p, OPCODE_MAX, lit, WRITEMASK_XYZW, id, dots); - /* 1, MAX2(in[0], 0), (in[0] > 0 ? 1 : 0), 1 + /* result[2] = (in > 0 ? 1 : 0) + * SLT lit.z, id.z, dots; # lit.z = (0 < dots.z) ? 1 : 0 */ - emit_op2(p, OPCODE_SLT, lit, WRITEMASK_Z, - lit, /* 0 */ - swizzle1(dots, X)); /* in[0] */ + emit_op2(p, OPCODE_SLT, lit, WRITEMASK_Z, swizzle1(id,Z), dots); } @@ -1007,6 +1011,14 @@ static void build_lighting( struct tnl_program *p ) struct ureg _bfc0 = undef, _bfc1 = undef; GLuint i; + /* + * NOTE: + * dot.x = dot(normal, VPpli) + * dot.y = dot(normal, halfAngle) + * dot.z = back.shininess + * dot.w = front.shininess + */ + for (i = 0; i < MAX_LIGHTS; i++) if (p->state->unit[i].light_enabled) nr_lights++; @@ -1144,10 +1156,13 @@ static void build_lighting( struct tnl_program *p ) /* Calculate dot products: */ - emit_op2(p, OPCODE_DP3, dots, WRITEMASK_X, normal, VPpli); - - if (!p->state->material_shininess_is_zero) + if (p->state->material_shininess_is_zero) { + emit_op2(p, OPCODE_DP3, dots, 0, normal, VPpli); + } + else { + emit_op2(p, OPCODE_DP3, dots, WRITEMASK_X, normal, VPpli); emit_op2(p, OPCODE_DP3, dots, WRITEMASK_Y, normal, half); + } /* Front face lighting: */ @@ -1181,15 +1196,18 @@ static void build_lighting( struct tnl_program *p ) if (!is_undef(att)) { + /* light is attenuated by distance */ emit_op1(p, OPCODE_LIT, lit, 0, dots); emit_op2(p, OPCODE_MUL, lit, 0, lit, att); emit_op3(p, OPCODE_MAD, _col0, 0, swizzle1(lit,X), ambient, _col0); } else if (!p->state->material_shininess_is_zero) { + /* there's a non-zero specular term */ emit_op1(p, OPCODE_LIT, lit, 0, dots); emit_op2(p, OPCODE_ADD, _col0, 0, ambient, _col0); } else { + /* no attenutation, no specular */ emit_degenerate_lit(p, lit, dots); emit_op2(p, OPCODE_ADD, _col0, 0, ambient, _col0); } |