diff options
Diffstat (limited to 'ir.cpp')
| -rw-r--r-- | ir.cpp | 104 |
1 files changed, 95 insertions, 9 deletions
@@ -97,9 +97,9 @@ ir_dereference::ir_dereference(ir_instruction *var, } -void -ir_dereference::set_swizzle(unsigned x, unsigned y, unsigned z, unsigned w, - unsigned count) +ir_swizzle::ir_swizzle(ir_rvalue *val, unsigned x, unsigned y, unsigned z, + unsigned w, unsigned count) + : val(val) { assert((count >= 1) && (count <= 4)); @@ -113,14 +113,100 @@ ir_dereference::set_swizzle(unsigned x, unsigned y, unsigned z, unsigned w, assert(z <= 3); assert(w <= 3); - selector.swizzle.x = x; - selector.swizzle.y = y; - selector.swizzle.z = z; - selector.swizzle.w = w; - selector.swizzle.num_components = count; - selector.swizzle.has_duplicates = dup_mask != 0; + mask.x = x; + mask.y = y; + mask.z = z; + mask.w = w; + mask.num_components = count; + mask.has_duplicates = dup_mask != 0; + + /* Based on the number of elements in the swizzle and the base type + * (i.e., float, int, unsigned, or bool) of the vector being swizzled, + * generate the type of the resulting value. + */ + type = glsl_type::get_instance(val->type->base_type, mask.num_components, 1); } +#define X 1 +#define R 5 +#define S 9 +#define I 13 + +ir_swizzle * +ir_swizzle::create(ir_rvalue *val, const char *str, unsigned vector_length) +{ + /* For each possible swizzle character, this table encodes the value in + * \c idx_map that represents the 0th element of the vector. For invalid + * swizzle characters (e.g., 'k'), a special value is used that will allow + * detection of errors. + */ + static const unsigned char base_idx[26] = { + /* a b c d e f g h i j k l m */ + R, R, I, I, I, I, R, I, I, I, I, I, I, + /* n o p q r s t u v w x y z */ + I, I, S, S, R, S, S, I, I, X, X, X, X + }; + + /* Each valid swizzle character has an entry in the previous table. This + * table encodes the base index encoded in the previous table plus the actual + * index of the swizzle character. When processing swizzles, the first + * character in the string is indexed in the previous table. Each character + * in the string is indexed in this table, and the value found there has the + * value form the first table subtracted. The result must be on the range + * [0,3]. + * + * For example, the string "wzyx" will get X from the first table. Each of + * the charcaters will get X+3, X+2, X+1, and X+0 from this table. After + * subtraction, the swizzle values are { 3, 2, 1, 0 }. + * + * The string "wzrg" will get X from the first table. Each of the characters + * will get X+3, X+2, R+0, and R+1 from this table. After subtraction, the + * swizzle values are { 3, 2, 4, 5 }. Since 4 and 5 are outside the range + * [0,3], the error is detected. + */ + static const unsigned char idx_map[26] = { + /* a b c d e f g h i j k l m */ + R+3, R+2, 0, 0, 0, 0, R+1, 0, 0, 0, 0, 0, 0, + /* n o p q r s t u v w x y z */ + 0, 0, S+2, S+3, R+0, S+0, S+1, 0, 0, X+3, X+0, X+1, X+2 + }; + + int swiz_idx[4] = { 0, 0, 0, 0 }; + unsigned i; + + + /* Validate the first character in the swizzle string and look up the base + * index value as described above. + */ + if ((str[0] < 'a') || (str[0] > 'z')) + return NULL; + + const unsigned base = base_idx[str[0] - 'a']; + + + for (i = 0; (i < 4) && (str[i] != '\0'); i++) { + /* Validate the next character, and, as described above, convert it to a + * swizzle index. + */ + if ((str[i] < 'a') || (str[i] > 'z')) + return NULL; + + swiz_idx[i] = idx_map[str[i] - 'a'] - base; + if ((swiz_idx[i] < 0) || (swiz_idx[i] >= (int) vector_length)) + return NULL; + } + + if (str[i] != '\0') + return NULL; + + return new ir_swizzle(val, swiz_idx[0], swiz_idx[1], swiz_idx[2], + swiz_idx[3], i); +} + +#undef X +#undef R +#undef S +#undef I ir_variable::ir_variable(const struct glsl_type *type, const char *name) |