diff options
| -rw-r--r-- | src/glsl/lower_ubo_reference.cpp | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/src/glsl/lower_ubo_reference.cpp b/src/glsl/lower_ubo_reference.cpp index 247620e6148..c8ec5c19f41 100644 --- a/src/glsl/lower_ubo_reference.cpp +++ b/src/glsl/lower_ubo_reference.cpp @@ -744,7 +744,31 @@ lower_ubo_reference_visitor::emit_access(bool is_write, * or 32 depending on the number of columns. */ assert(matrix_columns <= 4); - unsigned matrix_stride = glsl_align(matrix_columns * N, 16); + unsigned matrix_stride = 0; + /* Matrix stride for std430 mat2xY matrices are not rounded up to + * vec4 size. From OpenGL 4.3 spec, section 7.6.2.2 "Standard Uniform + * Block Layout": + * + * "2. If the member is a two- or four-component vector with components + * consuming N basic machine units, the base alignment is 2N or 4N, + * respectively." [...] + * "4. If the member is an array of scalars or vectors, the base alignment + * and array stride are set to match the base alignment of a single array + * element, according to rules (1), (2), and (3), and rounded up to the + * base alignment of a vec4." [...] + * "7. If the member is a row-major matrix with C columns and R rows, the + * matrix is stored identically to an array of R row vectors with C + * components each, according to rule (4)." [...] + * "When using the std430 storage layout, shader storage blocks will be + * laid out in buffer storage identically to uniform and shader storage + * blocks using the std140 layout, except that the base alignment and + * stride of arrays of scalars and vectors in rule 4 and of structures in + * rule 9 are not rounded up a multiple of the base alignment of a vec4." + */ + if (packing == GLSL_INTERFACE_PACKING_STD430 && matrix_columns == 2) + matrix_stride = 2 * N; + else + matrix_stride = glsl_align(matrix_columns * N, 16); const glsl_type *deref_type = deref->type->base_type == GLSL_TYPE_FLOAT ? glsl_type::float_type : glsl_type::double_type; |