Zack Buhman 511bfd1d0c remove duplicate start functions
This is now provided by default in saturn/common.mk.

Also updates moved header names, changed bit macro names, and changes
to the common.mk build process.
2023-07-30 18:03:19 +00:00

106 lines
3.7 KiB
C++

#include <stdint.h>
#include "vdp2.h"
#include "vdp1.h"
struct gimp_image {
uint8_t width;
uint8_t height;
uint8_t bytes_per_pixel; /* 2:RGB16, 3:RGB, 4:RGBA */
uint8_t pixel_data[48 * 48 * 3 + 1];
};
extern struct gimp_image chikorita;
inline uint16_t rgb15(const uint8_t * rgb24)
{
return ((rgb24[2] >> 3) << 10) // blue
| ((rgb24[1] >> 3) << 5) // green
| ((rgb24[0] >> 3) << 0); // red
}
uint32_t character_pattern_table(const uint32_t top)
{
const uint32_t image_size = chikorita.width * chikorita.height * 2; // in bytes of vdp1 vram
const uint32_t table_size = ((image_size) + 0x20 - 1) & (-0x20); // round up to the nearest multiple of 32
const uint32_t table_address = top - table_size;
uint16_t * table = &vdp1.vram.u16[(table_address / 2)];
for (int32_t y = 0; y < (int32_t)chikorita.height; y++) {
for (int32_t x = 0; x < (int32_t)chikorita.width; x++) {
int32_t pixel_index = (y * chikorita.width + x);
const uint8_t * rgb24 = &chikorita.pixel_data[pixel_index * 3];
table[pixel_index] = COLR__RGB | rgb15(rgb24);
}
}
return table_address;
}
void main()
{
uint32_t character_address;
uint32_t top = (sizeof (union vdp1_vram));
top = character_address = character_pattern_table(top);
// DISP: Please make sure to change this bit from 0 to 1 during V blank.
vdp2.reg.TVMD = ( TVMD__DISP | TVMD__LSMD__NON_INTERLACE
| TVMD__VRESO__240 | TVMD__HRESO__NORMAL_320);
// VDP2 User's Manual:
// "When sprite data is in an RGB format, sprite register 0 is selected"
// "When the value of a priority number is 0h, it is read as transparent"
//
// From a VDP2 perspective: in VDP1 16-color lookup table mode, VDP1 is still
// sending RGB data to VDP2. This sprite color data as configured in
// `color_lookup_table` from a VDP2 priority perspective uses sprite register 0.
//
// The power-on value of PRISA is zero. Set the priority for sprite register 0
// to some number greater than zero, so that the color data is not interpreted
// as "transparent".
vdp2.reg.PRISA = PRISA__S0PRIN(1); // Sprite register 0 PRIority Number
/* TVM settings must be performed from the second H-blank IN interrupt after the
V-blank IN interrupt to the H-blank IN interrupt immediately after the V-blank
OUT interrupt. */
// "normal" display resolution, 16 bits per pixel, 512x256 framebuffer
vdp1.reg.TVMR = TVMR__TVM__NORMAL;
// swap framebuffers every 1 cycle; non-interlace
vdp1.reg.FBCR = 0;
// during a framebuffer erase cycle, write the color "black" to each pixel
const uint16_t black = 0x0000;
vdp1.reg.EWDR = black;
// the EWLR/EWRR macros use somewhat nontrivial math for the X coordinates
// erase upper-left coordinate
vdp1.reg.EWLR = EWLR__16BPP_X1(0) | EWLR__Y1(0);
// erase lower-right coordinate
vdp1.reg.EWRR = EWRR__16BPP_X3(319) | EWRR__Y3(239);
vdp1.vram.cmd[0].CTRL = CTRL__JP__JUMP_NEXT | CTRL__COMM__SYSTEM_CLIP_COORDINATES;
vdp1.vram.cmd[0].LINK = 0;
vdp1.vram.cmd[0].XC = 319;
vdp1.vram.cmd[0].YC = 239;
vdp1.vram.cmd[1].CTRL = CTRL__JP__JUMP_NEXT | CTRL__COMM__LOCAL_COORDINATE;
vdp1.vram.cmd[1].LINK = 0;
vdp1.vram.cmd[1].XA = 0;
vdp1.vram.cmd[1].YA = 0;
vdp1.vram.cmd[2].CTRL = CTRL__JP__JUMP_NEXT | CTRL__COMM__NORMAL_SPRITE;
vdp1.vram.cmd[2].LINK = 0;
vdp1.vram.cmd[2].PMOD = PMOD__COLOR_MODE__RGB;
vdp1.vram.cmd[2].COLR = 0;
vdp1.vram.cmd[2].SRCA = character_address >> 3;
vdp1.vram.cmd[2].SIZE = SIZE__X(chikorita.width) | SIZE__Y(chikorita.height);
vdp1.vram.cmd[2].XA = 50;
vdp1.vram.cmd[2].YA = 50;
vdp1.vram.cmd[3].CTRL = CTRL__END;
// start drawing (execute the command list) on every frame
vdp1.reg.PTMR = PTMR__PTM__FRAME_CHANGE;
}