The wavy background: scanline scroll offsets fed by HBlank DMA. More...
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Functions | |
| void | DisplayScroll_ArmHBlankDma (void) |
| Scheduler callback for the wavy background: restarts DMA 0 each frame to copy the current page's BG1 to BG3 scroll offsets into the scroll registers one scanline at a time. | |
| void | DisplayScroll_BuildAndSwapHBlankPage (void) |
| Scheduler callback for the wavy background: fills the hidden page with each scanline's BG3, BG2 and BG1 offsets, the scroll plus a sine wave for x and for y (an axis with no step stays flat), then shows that page. | |
| void | DisplayScroll_DisarmHBlankDma (void) |
| Stops the wavy background: removes its two callbacks and stops DMA 0. | |
The wavy background: scanline scroll offsets fed by HBlank DMA.
Part of psynergy_effects.c, compiled only through it.
Definition in file wave_scroll.c.
| void DisplayScroll_ArmHBlankDma | ( | void | ) |
Scheduler callback for the wavy background: restarts DMA 0 each frame to copy the current page's BG1 to BG3 scroll offsets into the scroll registers one scanline at a time.
The first line is written directly; the DMA writes three words at each HBlank from then on.
Definition at line 11 of file wave_scroll.c.
Referenced by DisplayScroll_ArmHBlankDma(), DisplayScroll_DisarmHBlankDma(), DisplayScroll_InitializeHBlankDma(), and Ripple_Stop().
| void DisplayScroll_BuildAndSwapHBlankPage | ( | void | ) |
Scheduler callback for the wavy background: fills the hidden page with each scanline's BG3, BG2 and BG1 offsets, the scroll plus a sine wave for x and for y (an axis with no step stays flat), then shows that page.
Definition at line 44 of file wave_scroll.c.
Referenced by DisplayScroll_BuildAndSwapHBlankPage(), DisplayScroll_DisarmHBlankDma(), DisplayScroll_InitializeHBlankDma(), and Ripple_Stop().
| void DisplayScroll_DisarmHBlankDma | ( | void | ) |
Stops the wavy background: removes its two callbacks and stops DMA 0.
Definition at line 123 of file wave_scroll.c.
Referenced by DisplayScroll_DisarmHBlankDma(), and Reveal_ShowSecrets().