don't click here

Camera "lag" in Sonic 1

Discussion in 'Engineering & Reverse Engineering' started by Mercury, Jul 13, 2009.

Thread Status:
Not open for further replies.
Page 1 of 2
  1. Jul 13, 2009 #1
    Mercury

    Mercury

    His Name Is Sonic Tech Member
    1,740
    21
    18
    Location Location
    AeStHete
    I've searched but I can't seem to find any discussion of this.

    When Sonic jumps (in Sonic 1), the camera doesn't immediately follow him. It waits for a few steps. Then, after he reaches the apex of his jump, it waits again. Then, after he lands, it catches back up. I thought at first that it might have something to do with his speed, but it still isn't very clear to me.

    Furthermore, when Sonic moves left and right while on the ground, the camera lags behind a little, too.

    Does anyone know what controls the camera's behaviour? Presently in my engine, Sonic's physics feel correct, but without accurate camera "lag" they don't look correct.

    Thanks.
     
  2. Jul 13, 2009 #2
    nineko

    nineko

    I am the Holy Cat Tech Member
    6,308
    486
    63
    italy
  3. Jul 13, 2009 #3
    Mercury

    Mercury

    His Name Is Sonic Tech Member
    1,740
    21
    18
    Location Location
    AeStHete
  4. Jul 13, 2009 #4
    Sik

    Sik

    Sik is pronounced as "seek", not as "sick". Tech Member
    6,718
    1
    0
    being an asshole =P
    And now is when we kill Yuji Naka for making the camera behaviour so complicate :argh:

    I mean, seriously, what the hell?

    EDIT: you know, that post doesn't explain this:
    http://srb2town.sepwich.com/junk/Loophole.PNG

    Loophole aside, as you can see, Sonic is sightly shifted upwards - eventually, he's basically about one body shifted up when he reaches the peak of the loop. However, I assume that Sonic is considered to be on the floor, thereby he should be fixed at the center of the screen according to that explanation. How does this work then?
     
  5. Jul 13, 2009 #5
    saxman

    saxman

    Oldbie Tech Member
    3,297
    641
    93
    United States of America
    I'm not sure if you can read C code or not, but here is some code from my ProSonic engine that does the same thing:

    Code (Text):
    1. inline void PositionCamera(short x, short y){
    2.     int cam_offset_x = x - p->Camera_X_pos - (screen_resolution_x >> 1);
    3.     int cam_offset_y = y - p->Camera_Y_pos - (screen_resolution_y >> 1) - (p->Camera_Y_pos_bias - 0x60);
    4.     // obviously in your case, screen_resolution_x and screen_resolution_y are always going to be 320 and 224 respectively
    5.     
    6.     // IGNORE THESE TWO LINES
    7.     // if(fade_count != 0)
    8.     //     return;
    9.     
    10.     if(cam_offset_x > 0){
    11.         if(cam_offset_x > 0x10)
    12.             p->Camera_X_pos += 0x10;
    13.         else
    14.             p->Camera_X_pos += cam_offset_x;
    15.     }
    16.     
    17. &nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_x < -0x10){
    18. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_x < -0x20)
    19. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_X_pos -= 0x10;
    20. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    21. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_X_pos += (cam_offset_x + 0x10);
    22. &nbsp;&nbsp;&nbsp;&nbsp;}
    23. &nbsp;&nbsp;&nbsp;&nbsp;
    24. &nbsp;&nbsp;&nbsp;&nbsp;if(p->status & 4) // if player is rolling
    25. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cam_offset_y -= 5;
    26. &nbsp;&nbsp;&nbsp;&nbsp;
    27. &nbsp;&nbsp;&nbsp;&nbsp;if(p->status & 2){ // if player is in the air
    28. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->status & 3){ // if player is facing left
    29. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x15){
    30. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x25)
    31. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += 0x10;
    32. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    33. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y - 0x15);
    34. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    35. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    36. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x2B){
    37. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x3B)
    38. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos -= 0x10;
    39. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    40. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y + 0x2B);
    41. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    42. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    43. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else{ // if player is facing right
    44. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->y_vel > 0x600 || p->y_vel < -0x600){
    45. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x10){
    46. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x20)
    47. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += 0x10;
    48. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    49. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y - 0x10);
    50. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    51. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    52. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x30){
    53. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x40)
    54. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos -= 0x10;
    55. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    56. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += cam_offset_y + 0x30;
    57. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    58. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    59. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else{
    60. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x10){
    61. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x16)
    62. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += 0x6;
    63. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    64. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y - 0x10);
    65. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    66. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    67. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x30){
    68. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x36)
    69. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos -= 0x6;
    70. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    71. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += cam_offset_y + 0x30;
    72. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    73. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    74. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    75. &nbsp;&nbsp;&nbsp;&nbsp;}
    76. &nbsp;&nbsp;&nbsp;&nbsp;else{
    77. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->y_vel > 0x600 || p->y_vel < -0x600){
    78. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x10){
    79. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x20)
    80. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += 0x10;
    81. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    82. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y - 0x10);
    83. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    84. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    85. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else if(cam_offset_y < 0x10){
    86. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x20)
    87. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos -= 0x10;
    88. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    89. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y + 0x10);
    90. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    91. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    92. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else{
    93. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > -0x10){
    94. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > -0xA)
    95. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += 0x6;
    96. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    97. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y + 0x10);
    98. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    99. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    100. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else if(cam_offset_y < -0x10){
    101. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x16)
    102. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos -= 0x6;
    103. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    104. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y + 0x10);
    105. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    106. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    107. &nbsp;&nbsp;&nbsp;&nbsp;}
    108. &nbsp;&nbsp;&nbsp;&nbsp;
    109. &nbsp;&nbsp;&nbsp;&nbsp;
    110. &nbsp;&nbsp;&nbsp;&nbsp;////////////////////
    111. &nbsp;&nbsp;&nbsp;&nbsp;// Camera correction
    112. &nbsp;&nbsp;&nbsp;&nbsp;////////////////////
    113. &nbsp;&nbsp;&nbsp;&nbsp;
    114. &nbsp;&nbsp;&nbsp;&nbsp;// for the X axis
    115. &nbsp;&nbsp;&nbsp;&nbsp;// IGNORE THE LINE BELOW
    116. &nbsp;&nbsp;&nbsp;&nbsp;// if(!camera_mode){
    117. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->Camera_Max_X_pos - p->Camera_X_pos <= 0x100)
    118. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Min_X_pos = p->Camera_Max_X_pos - 0x100;
    119. &nbsp;&nbsp;&nbsp;&nbsp;// IGNORE THIS LINE TOO
    120. &nbsp;&nbsp;&nbsp;&nbsp;// }
    121. &nbsp;&nbsp;&nbsp;&nbsp;if(p->Camera_X_pos < p->Camera_Min_X_pos)
    122. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_X_pos = p->Camera_Min_X_pos;
    123. &nbsp;&nbsp;&nbsp;&nbsp;else if(p->Camera_X_pos > p->Camera_Max_X_pos - (screen_resolution_x-320))
    124. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_X_pos = p->Camera_Max_X_pos - (screen_resolution_x-320);
    125. &nbsp;&nbsp;&nbsp;&nbsp;
    126. &nbsp;&nbsp;&nbsp;&nbsp;// for the Y axis
    127. &nbsp;&nbsp;&nbsp;&nbsp;if(p->Camera_Y_pos <= p->Camera_Min_Y_pos){
    128. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->Camera_Min_Y_pos < 0){
    129. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos &= z.Act[act].Stage[stage].WrapPoint-1;
    130. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    131. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->Camera_Y_pos >= 0)
    132. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += ((p->Camera_Max_Y_pos - (screen_resolution_y-224)) << 8);
    133. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    134. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos &= ((z.Act[act].Stage[stage].WrapPoint-1 << 8) + 0xFF);
    135. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    136. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    137. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos = p->Camera_Min_Y_pos;
    138. &nbsp;&nbsp;&nbsp;&nbsp;}
    139. &nbsp;&nbsp;&nbsp;&nbsp;
    140. &nbsp;&nbsp;&nbsp;&nbsp;// IGNORE THIS LINE
    141. &nbsp;&nbsp;&nbsp;&nbsp;// if(screen_resolution_y-224 >= 0){
    142. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->Camera_Y_pos >= p->Camera_Max_Y_pos
    143. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; && p->Camera_Y_pos >= z.Act[act].Stage[stage].WrapPoint
    144. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; && p->Camera_Min_Y_pos < 0){
    145. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos &= z.Act[act].Stage[stage].WrapPoint-1;
    146. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->y_pos &= z.Act[act].Stage[stage].WrapPoint-1;
    147. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    148. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else if(p->Camera_Y_pos > p->Camera_Max_Y_pos + (screen_resolution_y-224))
    149. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos = p->Camera_Max_Y_pos + (screen_resolution_y-224);
    150. &nbsp;&nbsp;&nbsp;&nbsp;// IGNORE THESE LINES
    151. &nbsp;&nbsp;&nbsp;&nbsp;// }
    152. &nbsp;&nbsp;&nbsp;&nbsp;// else{
    153. &nbsp;&nbsp;&nbsp;&nbsp;// &nbsp;&nbsp;&nbsp;&nbsp;if(p->Camera_Y_pos >= p->Camera_Max_Y_pos
    154. &nbsp;&nbsp;&nbsp;&nbsp;// &nbsp;&nbsp;&nbsp;&nbsp; && p->Camera_Y_pos >= z.Act[act].Stage[stage].WrapPoint
    155. &nbsp;&nbsp;&nbsp;&nbsp;// &nbsp;&nbsp;&nbsp;&nbsp; && p->Camera_Min_Y_pos < 0){
    156. &nbsp;&nbsp;&nbsp;&nbsp;// &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos &= z.Act[act].Stage[stage].WrapPoint-1;
    157. &nbsp;&nbsp;&nbsp;&nbsp;// &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->y_pos &= z.Act[act].Stage[stage].WrapPoint-1;
    158. &nbsp;&nbsp;&nbsp;&nbsp;// &nbsp;&nbsp;&nbsp;&nbsp;}
    159. &nbsp;&nbsp;&nbsp;&nbsp;// &nbsp;&nbsp;&nbsp;&nbsp;else if(p->Camera_Y_pos > p->Camera_Max_Y_pos - (screen_resolution_y-224))
    160. &nbsp;&nbsp;&nbsp;&nbsp;// &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos = p->Camera_Max_Y_pos - (screen_resolution_y-224);
    161. &nbsp;&nbsp;&nbsp;&nbsp;// }
    162. &nbsp;&nbsp;&nbsp;&nbsp;
    163. &nbsp;&nbsp;&nbsp;&nbsp;
    164. &nbsp;&nbsp;&nbsp;&nbsp;
    165. &nbsp;&nbsp;&nbsp;&nbsp;p->Camera_X_pos_coarse = (p->Camera_X_pos - 128) / 256;
    166. }
    I commented-out some lines you don't need to pay any attention to. The function inputs x and y are the X and Y positions of the player. The only thing not taken into account above is the spindash lag, because I don't know how that works.

    Here are some descriptions for the variables used:

     
  6. Jul 14, 2009 #6
    Sik

    Sik

    Sik is pronounced as "seek", not as "sick". Tech Member
    6,718
    1
    0
    being an asshole =P
    I still don't see any code that would make Sonic look offseted upwards on the screen when going up a loop. Did I miss something, is it a side-effect or what?
     
  7. Jul 14, 2009 #7
    saxman

    saxman

    Oldbie Tech Member
    3,297
    641
    93
    United States of America
    I have no clue what you mean. Can you explain or show a screenshot? I just did a frame-by-frame comparison between Sonic 2 and my engine both running Chemical Plant act 1, and the camera is the same on every frame going all the way around the loop. Whatever it is that you're seeing, that code does it.
     
  8. Jul 14, 2009 #8
    Armada

    Armada

    Sometimes I do things Member
    338
    0
    0
    The only way I can see it from that image is that Sonic (although rotated) still has the same mask. It is then possible to assume he has not passed his borders for moving on the screen. Also, I didn't check the coordinates, but it also appears his spike is in the center of the screen.

    Of course I know nothing about how collisions and masks are checked on a rotated Sonic.
     
  9. Jul 14, 2009 #9
    JoseTB

    JoseTB

    Tech Member
    716
    59
    28
    I don't remember for sure, but there are chances the mappings of that animation were intentionally shifted from the origin, thus giving that effect even if the camera is still centered.
     
  10. Jul 15, 2009 #10
    Mercury

    Mercury

    His Name Is Sonic Tech Member
    1,740
    21
    18
    Location Location
    AeStHete
    Saxman: Yes, I can read C code, but I have a question. Why is there a difference in the vertical part of the code depending on whether or not the player is facing left or right? When I converted your code to my engine, things were alright when moving to the left, but Sonic went right out of the vertical boundaries when moving to the right. Now, I may have erred when making the conversion, but I still wonder why the difference in the first place. What does the horizontal direction have to do with it?
     
  11. Jul 15, 2009 #11
    saxman

    saxman

    Oldbie Tech Member
    3,297
    641
    93
    United States of America
    I tested the code to make sure it worked and commented out all the things I commented out in the version I posted, and it still works in my engine. I'd say it's likely an error in your conversion of the code. Horizontal direction should make no difference in the camera's behaviour.

    The only thing related to the horizontal movement is this: when the player is on the ground, there's a 16 pixel range where the camera doesn't move (from 144 to 160.) To the left of 144 or to the right of 160, the camera will move. It is only allowed to move 16 pixels per frame.
     
  12. Jul 15, 2009 #12
    Sik

    Sik

    Sik is pronounced as "seek", not as "sick". Tech Member
    6,718
    1
    0
    being an asshole =P
    Um, I just rechecked to be sure, and yeah, Sonic stays in the same place... though it looks like the bottommost part of the sprite of Sonic is aligned with the middle of the screen, which is probably what gave me the feeling that Sonic moved vertically =/
     
  13. Jul 15, 2009 #13
    saxman

    saxman

    Oldbie Tech Member
    3,297
    641
    93
    United States of America
    They did that on purpose to fool you. Damn them! :argh:
     
  14. Jul 15, 2009 #14
    Mercury

    Mercury

    His Name Is Sonic Tech Member
    1,740
    21
    18
    Location Location
    AeStHete
    So why does it say "if player is facing left" and "if player is facing right" ?

    Code (Text):
    1. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->status & 3){ // if player is facing left
    2. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x15){
    3. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x25)
    4. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += 0x10;
    5. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    6. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y - 0x15);
    7. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    8. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    9. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x2B){
    10. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x3B)
    11. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos -= 0x10;
    12. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    13. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y + 0x2B);
    14. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    15. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    16. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else{ // if player is facing right
    17. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(p->y_vel > 0x600 || p->y_vel < -0x600){
    18. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x10){
    19. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x20)
    20. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += 0x10;
    21. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    22. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y - 0x10);
    23. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    24. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    25. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x30){
    26. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x40)
    27. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos -= 0x10;
    28. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    29. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += cam_offset_y + 0x30;
    30. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    31. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    32. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else{
    33. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x10){
    34. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y > 0x16)
    35. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += 0x6;
    36. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    37. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += (cam_offset_y - 0x10);
    38. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    39. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    40. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x30){
    41. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(cam_offset_y < -0x36)
    42. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos -= 0x6;
    43. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else
    44. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p->Camera_Y_pos += cam_offset_y + 0x30;
    45. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    46. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
    47. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
     
  15. Jul 15, 2009 #15
    saxman

    saxman

    Oldbie Tech Member
    3,297
    641
    93
    United States of America
    That's the reason for it. It allows a little bit of a buffer where the player can move and the camera stays still.
     
  16. Jul 15, 2009 #16
    Mercury

    Mercury

    His Name Is Sonic Tech Member
    1,740
    21
    18
    Location Location
    AeStHete
    I understand that - that's the horizontal boundary, but the code I posted above is manipulating the vertical variables. The values are 0x15 and 0x2B, and so on, when facing left, but 0x10 and 0x30 when facing right. Also, it only bothers checking p->y_vel when moving right - you'd think it would need to do that in both cases. I still don't understand why the vertical boundary should behave differently based upon the direction facing.
     
  17. Jul 15, 2009 #17
    saxman

    saxman

    Oldbie Tech Member
    3,297
    641
    93
    United States of America
    Okay, I can't read my own code! You make a very good point, and I'm trying to read what I wrote, and honestly I don't even understand it. It works in my engine, but I'm starting to question why it works in ProSonic, because it looks strange to me. I remember when writing it that there was a very good reason for grouping the branches in the way that I did, but I didn't leave comments to remind me. So now I can't remember, and I don't know what's going on in that code.

    I'll give you a general summary of what the camera is supposed to do:


    - if player is in the air
    - - - - camera X is allowed to move 16 pixels at a time
    - - - - camera Y is allowed to move 16 pixels at a time
    - - - - camera scrolls if player X is less than -16 or greater than 0 (from center)
    - - - - camera scrolls if player Y is less than -43 or greater than 37 (from center)

    - else, player is on the ground
    - - - - camera X is allowed to move 16 pixels at a time
    - - - - camera Y is allowed to move 6 pixels at a time
    - - - - camera scrolls if player X is less than -16 or greater than 0 (from center)
    - - - - camera scrolls if player Y is not 0 (from center)

    - if player is rolling
    - - - - camera Y is moved up 5 pixels to account for player's center point being shifted


    I think that covers it all. And as I said, I don't know how the spindash lag works exactly. If anyone does know, let me know!
     
  18. Jul 15, 2009 #18
    Mercury

    Mercury

    His Name Is Sonic Tech Member
    1,740
    21
    18
    Location Location
    AeStHete
    I hope there's not a bug in your engine. :psyduck:

    Thanks for the info, by the way, I've got my camera system all coded now, and it's working great!

    I've been looking at the spindash lag myself, lately, but I can't make head nor tail of it, either. Fortunately I'm using a Sonic CD style spindash in my engine.
     
  19. Jul 15, 2009 #19
    JoseTB

    JoseTB

    Tech Member
    716
    59
    28
  20. Jul 16, 2009 #20
    saxman

    saxman

    Oldbie Tech Member
    3,297
    641
    93
    United States of America
    Aha, so the camera works on a log of past frames. My tests of the camera in action conclude that it goes back 16 positions in the past, and after holding there for 8 frames, it proceeds to move based on every other player X position for another 8 frames. After 16 frames are done in all, the camera reverts back to normal.
     
Page 1 of 2
Thread Status:
Not open for further replies.