| 1,15 → 1,52 |
|---|
| |
| |
| Implementation detail differences |
| ================================= |
| |
| FilterFoundry tries to be as compatible with Filter Factory as possible. |
| However, results are usually not 100% equal because functions like |
| cos, sin, sqr, etc., have different accuracy due to the underlying |
| implementation. |
| However, there are some differences which are explained in this documentation. |
| |
| Furthermore, there are the following known differences between |
| Filter Foundry and Filter Factory: |
| Various implementations |
| ----------------------- |
| |
| In the source-code file funcs.c, some functions are implemented twice: |
| One instance is the default implementation (older Filter Foundry versions used), |
| and one instance is a 100% replica of the Filter Factory code, obtained |
| from the "OPER" resource. |
| (More information at https://misc.daniel-marschall.de/projects/filter_factory/res_oper.html ) |
| If required, the compiler-definitions "use_filterfactory_implementation_*" |
| can be set or unset to select the implementation. |
| |
| In Filter Foundry 1.7.0.8, following functions have been updated to the |
| Filter Factory replica: |
| - rnd |
| - cos |
| - sin |
| - tan |
| - r2x |
| - r2y |
| - rad |
| - c2d |
| - c2m |
| - sqr |
| |
| TODO: |
| - d |
| - m |
| - M |
| |
| |
| sqr(x) |
| ------ |
| |
| Filter Factory: |
| |
| sqr(x)=x for x < 0 |
| |
| Filter Foundry (prior to 1.7.0.8): |
| |
| sqr(x)=0 for x < 0 |
| |
| i, u, v (Testcase iuv.afs) |
| ------- |
| |
| 50,7 → 87,7 |
|---|
| Filter Foundry initializes it as `r=g=b=255` |
| |
| |
| rnd(a,b) (Testcases rnd_*) |
| rnd(a,b) (Testcases rnd*) |
| -------- |
| |
| Filter Factory uses Donald E. Knuth's subtractive random number generator algorithm, |
| 61,8 → 98,8 |
|---|
| so that the output of rnd(a,b) is exactly the same now. |
| |
| |
| rnd(a,b) and rst(i) (Testcases rnd*.afs and rst_*.afs) |
| ------------------- |
| rst(i) (Testcases rnd*.afs and rst_*.afs) |
| ------ |
| |
| Filter Factory contains an undocumented function that sets the seed for the random number generator. |
| |