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Copy ObjAffineSet implementation from GBA.js

This commit is contained in:
Jeffrey Pfau 2013-05-03 01:43:39 -07:00
parent 2bc11c9aac
commit 6ef3e3b6a8
1 changed files with 34 additions and 0 deletions
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34
src/gba/gba-bios.c
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@ -78,6 +78,37 @@ static void _FastCpuSet(struct GBA* gba) {
}
}
static void _ObjAffineSet(struct GBA* gba) {
int i = gba->cpu.gprs[2];
float sx, sy;
float theta;
int offset = gba->cpu.gprs[0];
int destination = gba->cpu.gprs[1];
int diff = gba->cpu.gprs[3];
float a, b, c, d;
while (i--) {
// [ sx 0 ] [ cos(theta) -sin(theta) ] [ A B ]
// [ 0 sy ] * [ sin(theta) cos(theta) ] = [ C D ]
sx = GBALoad16(&gba->memory.d, offset) / 256.f;
sy = GBALoad16(&gba->memory.d, offset + 2) / 256.f;
theta = (GBALoadU16(&gba->memory.d, offset + 4) >> 8) / 128.f * M_PI;
offset += 6;
// Rotation
a = d = cosf(theta);
b = c = sinf(theta);
// Scale
a *= sx;
b *= -sx;
c *= sy;
d *= sy;
GBAStore16(&gba->memory.d, destination, a * 256);
GBAStore16(&gba->memory.d, destination + diff, b * 256);
GBAStore16(&gba->memory.d, destination + diff * 2, c * 256);
GBAStore16(&gba->memory.d, destination + diff * 3, d * 256);
destination += diff * 4;
}
}
static void _MidiKey2Freq(struct GBA* gba) {
uint32_t key = GBALoad32(&gba->memory.d, gba->cpu.gprs[0] + 4);
gba->cpu.gprs[0] = key / powf(2, (180.f - gba->cpu.gprs[1] - gba->cpu.gprs[2] / 256.f) / 12.f);
@ -131,6 +162,9 @@ void GBASwi16(struct ARMBoard* board, int immediate) {
case 0xC:
_FastCpuSet(gba);
break;
case 0xF:
_ObjAffineSet(gba);
break;
case 0x11:
case 0x12:
switch (gba->cpu.gprs[1] >> BASE_OFFSET) {