diff options
Diffstat (limited to 'src/mesa/shader/slang/slang_assemble_typeinfo.c')
-rw-r--r-- | src/mesa/shader/slang/slang_assemble_typeinfo.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/src/mesa/shader/slang/slang_assemble_typeinfo.c b/src/mesa/shader/slang/slang_assemble_typeinfo.c index 21b31091ea..6a87ef3340 100644 --- a/src/mesa/shader/slang/slang_assemble_typeinfo.c +++ b/src/mesa/shader/slang/slang_assemble_typeinfo.c @@ -32,6 +32,123 @@ #include "slang_assemble.h" #include "slang_compile.h" #include "slang_error.h" +#include "prog_instruction.h" + + + + +/** + * Checks if a field selector is a general swizzle (an r-value swizzle + * with replicated components or an l-value swizzle mask) for a + * vector. Returns GL_TRUE if this is the case, <swz> is filled with + * swizzle information. Returns GL_FALSE otherwise. + */ +GLboolean +_slang_is_swizzle(const char *field, GLuint rows, slang_swizzle * swz) +{ + GLuint i; + GLboolean xyzw = GL_FALSE, rgba = GL_FALSE, stpq = GL_FALSE; + + /* init to undefined. + * We rely on undefined/nil values to distinguish between + * regular swizzles and writemasks. + * For example, the swizzle ".xNNN" is the writemask ".x". + * That's different than the swizzle ".xxxx". + */ + for (i = 0; i < 4; i++) + swz->swizzle[i] = SWIZZLE_NIL; + + /* the swizzle can be at most 4-component long */ + swz->num_components = slang_string_length(field); + if (swz->num_components > 4) + return GL_FALSE; + + for (i = 0; i < swz->num_components; i++) { + /* mark which swizzle group is used */ + switch (field[i]) { + case 'x': + case 'y': + case 'z': + case 'w': + xyzw = GL_TRUE; + break; + case 'r': + case 'g': + case 'b': + case 'a': + rgba = GL_TRUE; + break; + case 's': + case 't': + case 'p': + case 'q': + stpq = GL_TRUE; + break; + default: + return GL_FALSE; + } + + /* collect swizzle component */ + switch (field[i]) { + case 'x': + case 'r': + case 's': + swz->swizzle[i] = 0; + break; + case 'y': + case 'g': + case 't': + swz->swizzle[i] = 1; + break; + case 'z': + case 'b': + case 'p': + swz->swizzle[i] = 2; + break; + case 'w': + case 'a': + case 'q': + swz->swizzle[i] = 3; + break; + } + + /* check if the component is valid for given vector's row count */ + if (rows <= swz->swizzle[i]) + return GL_FALSE; + } + + /* only one swizzle group can be used */ + if ((xyzw && rgba) || (xyzw && stpq) || (rgba && stpq)) + return GL_FALSE; + + return GL_TRUE; +} + + + +/** + * Checks if a general swizzle is an l-value swizzle - these swizzles + * do not have duplicated fields. Returns GL_TRUE if this is a + * swizzle mask. Returns GL_FALSE otherwise + */ +GLboolean +_slang_is_swizzle_mask(const slang_swizzle * swz, GLuint rows) +{ + GLuint i, c = 0; + + /* the swizzle may not be longer than the vector dim */ + if (swz->num_components > rows) + return GL_FALSE; + + /* the swizzle components cannot be duplicated */ + for (i = 0; i < swz->num_components; i++) { + if ((c & (1 << swz->swizzle[i])) != 0) + return GL_FALSE; + c |= 1 << swz->swizzle[i]; + } + + return GL_TRUE; +} GLvoid |