[PSX] Xebra/Arbex 17/01/17

Xebra (2017/01/17) Changelog:

• Correspondence to incorrect display area setting

05 jan 2018

• Fix modification of drawing function by OpenGL

24 dec 2017

• Enhancement of disc image creation function and rendering function by OpenGL

07 dec 2017

• ???

02/11/17

• ???

17/07/11

1. Slightly reduce data volume. In GTE, division is performed by reciprocal integration, and its inverse value is inferior in accuracy. It was obvious that the common value for each group was refined.  However, the calculation formula for refinement was unknown (There is only the Newton's law or the Gold Schmidt method as the theoretical formula When dealing with integers, how to round numbers is arbitrary by the designer, It can not be theoretically derived). Although it was unknown, it is not a large amount of data for software on PC I wish I could prepare the whole number as an immediate value table (This is effective also in terms of reducing the amount of computation at the time of execution) 
   When checking the calculation formula of the refinement indicated by nocash this time, since we saw an agreement in total, I decided to adopt the calculation formula.
   As an actual utility, compressed data which was 4000 bytes in old algorithm, It is reduced to 257 bytes with the new algorithm. Although the normal distribution data used by the SPU was held for all the sections, Because it is bilaterally symmetrical, we deleted the half section.
2. Center display of screen at startup

Final Fantasy IX (Square Electronic Arts L.L.C., Nov 14, 2000)

17/06/10

• The default value of Stall Rate (GPU - in) from 0x14 to 0x8 at the above review. I tried to change it, so it was quite probable that this was an enemy case It returned to 0x14

17/06/08

• Transfer rate (GPU-chain) is unknown from when it is about. It was fixed because it was invalidated. Since the tag part and the data part are too different in the rate, We made them separately, and we used coefficients of GPU-in for the data part.

Xebra (2017/03/25) Changelog:

• CD: Correction of physical position information during reading In a recording medium having a large influence of mechanical elements such as thermal expansion, distortion, eccentricity and vibration Since it is impossible to move the header to the correct position with a single shot. After moving to the position it is estimated that you will wait for the target position to be encountered while leading. Then, for specifying the position, the Q channel of the subcode, that is, the physical position information It is inferred that it will be obtained in advance. Therefore, the physical position information during reading is 2 to 3 sectors It is considered to precede.

Xebra (2017/03/17) Changelog:

• Timer 1 has a mode to count up by the system clock And a mode to count up by HSYNC, Both of them can stop counting up during VBLANK, Because I did not think there was a situation to stop in the system clock mode, For the sake of simplicity, we have adopted a pseudo-reproduction that counts up slowly without stopping. Recently I found out that there is a problematic game. Even in the system clock mode, it stopped properly.

Xebra (2016/10/25) Changelog:

Fixed GPU.
MoveImage, it did not assume the priority bit processing in LoadImage Fixed.
While reading the copy source in MoveImage was always to be preceded, since it was found that a simple design which is reset for each block line fixed.
In line drawing, it did not assume an illegal drawing area (xmin> xmax)
A phenomenon in which the image is distorted to be due to the fact that the sprite is two dots at a time processing It was to reproduce.

Xebra (2016/06/04) Changelog:

That the partial derivative of the UV coordinates with precision 12-bit fixed decimal Was aware of ago, but was incorrect to take reference points for to suppress the error that did not reproduce the actual Street sare with high precision, which has been running.  Relative errors (decided by the convenience of the drawing was adopt unconsciously y point values minimum)  Recently finally realized as actual behavior and may be dropped precision.  Also what times or serif play a soft failure to come out it was a behavior of CD just a little bit back to the previous ones.

Xebra (2016/05/12) Changelog:

• FIX: because there was a piece in binary conversion data associated with self-modifying disabling more than necessary. Made in setting the coefficient of axial controller [Rate] 0, [Base], [Rate] to calculate.
• The base address is shown in the Show Values.