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-rw-r--r--GPU.cpp773
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+/*
+ Copyright 2016-2017 StapleButter
+
+ This file is part of melonDS.
+
+ melonDS is free software: you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation, either version 3 of the License, or (at your option)
+ any later version.
+
+ melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#include <stdio.h>
+#include <string.h>
+#include "NDS.h"
+#include "GPU.h"
+
+
+namespace GPU
+{
+
+#define LINE_CYCLES (355*6 * 2)
+#define FRAME_CYCLES (LINE_CYCLES * 263)
+
+u16 VCount;
+
+u16 DispStat[2], VMatch[2];
+
+u8 Palette[2*1024];
+u8 OAM[2*1024];
+
+u8 VRAM_A[128*1024];
+u8 VRAM_B[128*1024];
+u8 VRAM_C[128*1024];
+u8 VRAM_D[128*1024];
+u8 VRAM_E[ 64*1024];
+u8 VRAM_F[ 16*1024];
+u8 VRAM_G[ 16*1024];
+u8 VRAM_H[ 32*1024];
+u8 VRAM_I[ 16*1024];
+u8* VRAM[9] = {VRAM_A, VRAM_B, VRAM_C, VRAM_D, VRAM_E, VRAM_F, VRAM_G, VRAM_H, VRAM_I};
+
+u8 VRAMCNT[9];
+u8 VRAMSTAT;
+
+u8* VRAM_ABG[128];
+u8* VRAM_AOBJ[128];
+u8* VRAM_BBG[128];
+u8* VRAM_BOBJ[128];
+u8* VRAM_LCD[128];
+u8* VRAM_ARM7[2];
+
+u16 Framebuffer[256*192*2];
+
+GPU2D* GPU2D_A;
+GPU2D* GPU2D_B;
+
+
+void Init()
+{
+ GPU2D_A = new GPU2D(0);
+ GPU2D_B = new GPU2D(1);
+}
+
+void Reset()
+{
+ VCount = 0;
+
+ DispStat[0] = 0;
+ DispStat[1] = 0;
+ VMatch[0] = 0;
+ VMatch[1] = 0;
+
+ memset(Palette, 0, 2*1024);
+ memset(OAM, 0, 2*1024);
+
+ memset(VRAM_A, 0, 128*1024);
+ memset(VRAM_B, 0, 128*1024);
+ memset(VRAM_C, 0, 128*1024);
+ memset(VRAM_D, 0, 128*1024);
+ memset(VRAM_E, 0, 64*1024);
+ memset(VRAM_F, 0, 16*1024);
+ memset(VRAM_G, 0, 16*1024);
+ memset(VRAM_H, 0, 32*1024);
+ memset(VRAM_I, 0, 16*1024);
+
+ memset(VRAMCNT, 0, 9);
+ VRAMSTAT = 0;
+
+ memset(VRAM_ABG, 0, sizeof(u8*)*128);
+ memset(VRAM_AOBJ, 0, sizeof(u8*)*128);
+ memset(VRAM_BBG, 0, sizeof(u8*)*128);
+ memset(VRAM_BOBJ, 0, sizeof(u8*)*128);
+ memset(VRAM_LCD, 0, sizeof(u8*)*128);
+ memset(VRAM_ARM7, 0, sizeof(u8*)*2);
+
+ for (int i = 0; i < 256*192*2; i++)
+ {
+ Framebuffer[i] = 0x7FFF;
+ }
+
+ GPU2D_A->Reset();
+ GPU2D_B->Reset();
+
+ GPU2D_A->SetFramebuffer(&Framebuffer[0*192]);
+ GPU2D_B->SetFramebuffer(&Framebuffer[256*192]);
+}
+
+
+// VRAM mapping shit.
+// TODO eventually: work out priority orders in case of overlaps. there _are_ games that map overlapping banks.
+
+void MapVRAM_AB(u32 bank, u8 cnt)
+{
+ u8 oldcnt = VRAMCNT[bank];
+ VRAMCNT[bank] = cnt;
+
+ if (oldcnt == cnt) return;
+
+ u8 oldofs = (oldcnt >> 3) & 0x3;
+ u8 ofs = (cnt >> 3) & 0x3;
+
+ u8* vram = VRAM[bank];
+
+ if (oldcnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (oldcnt & 0x3)
+ {
+ case 0:
+ vrammap = &VRAM_LCD[bank<<3];
+ break;
+
+ case 1:
+ vrammap = &VRAM_ABG[oldofs<<3];
+ break;
+
+ case 2:
+ oldofs &= 0x1;
+ vrammap = &VRAM_AOBJ[oldofs<<3];
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap = NULL;
+ }
+ }
+
+ if (cnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (cnt & 0x3)
+ {
+ case 0:
+ vrammap = &VRAM_LCD[bank<<3];
+ break;
+
+ case 1:
+ vrammap = &VRAM_ABG[ofs<<3];
+ break;
+
+ case 2:
+ ofs &= 0x1;
+ vrammap = &VRAM_AOBJ[ofs<<3];
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap = vram;
+ }
+ }
+}
+
+void MapVRAM_CD(u32 bank, u8 cnt)
+{
+ u8 oldcnt = VRAMCNT[bank];
+ VRAMCNT[bank] = cnt;
+
+ VRAMSTAT &= ~(1 << (bank-2));
+
+ if (oldcnt == cnt) return;
+
+ u8 oldofs = (oldcnt >> 3) & 0x7;
+ u8 ofs = (cnt >> 3) & 0x7;
+
+ u8* vram = VRAM[bank];
+
+ if (oldcnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (oldcnt & 0x7)
+ {
+ case 0:
+ vrammap = &VRAM_LCD[bank<<3];
+ break;
+
+ case 1:
+ vrammap = &VRAM_ABG[oldofs<<3];
+ break;
+
+ case 2:
+ oldofs &= 0x1;
+ VRAM_ARM7[oldofs] = NULL;
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+
+ case 4:
+ if (bank == 2)
+ vrammap = &VRAM_BBG[0];
+ else
+ vrammap = &VRAM_BOBJ[0];
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap = NULL;
+ }
+ }
+
+ if (cnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (cnt & 0x7)
+ {
+ case 0:
+ vrammap = &VRAM_LCD[bank<<3];
+ break;
+
+ case 1:
+ vrammap = &VRAM_ABG[ofs<<3];
+ break;
+
+ case 2:
+ ofs &= 0x1;
+ VRAM_ARM7[ofs] = vram;
+ VRAMSTAT |= (1 << (bank-2));
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+
+ case 4:
+ if (bank == 2)
+ vrammap = &VRAM_BBG[0];
+ else
+ vrammap = &VRAM_BOBJ[0];
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap++ = vram; vram += 0x4000;
+ *vrammap = vram;
+ }
+ }
+}
+
+void MapVRAM_E(u32 bank, u8 cnt)
+{
+ u8 oldcnt = VRAMCNT[bank];
+ VRAMCNT[bank] = cnt;
+
+ if (oldcnt == cnt) return;
+
+ u8 oldofs = (oldcnt >> 3) & 0x7;
+ u8 ofs = (cnt >> 3) & 0x7;
+
+ u8* vram = VRAM[bank];
+
+ if (oldcnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (oldcnt & 0x7)
+ {
+ case 0:
+ VRAM_LCD[0x20] = NULL;
+ VRAM_LCD[0x21] = NULL;
+ VRAM_LCD[0x22] = NULL;
+ VRAM_LCD[0x23] = NULL;
+ break;
+
+ case 1:
+ vrammap = &VRAM_ABG[0];
+ break;
+
+ case 2:
+ vrammap = &VRAM_AOBJ[0];
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+
+ case 4:
+ // BG EXTPAL -- TODO
+ break;
+
+ case 5:
+ // OBJ EXTPAL -- TODO
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap = NULL;
+ }
+ }
+
+ if (cnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (cnt & 0x7)
+ {
+ case 0:
+ VRAM_LCD[0x20] = &vram[0x0000];
+ VRAM_LCD[0x21] = &vram[0x4000];
+ VRAM_LCD[0x22] = &vram[0x8000];
+ VRAM_LCD[0x23] = &vram[0xC000];
+ break;
+
+ case 1:
+ vrammap = &VRAM_ABG[0];
+ break;
+
+ case 2:
+ vrammap = &VRAM_AOBJ[0];
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+
+ case 4:
+ // BG EXTPAL -- TODO
+ break;
+
+ case 5:
+ // OBJ EXTPAL -- TODO
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = &vram[0x0000];
+ *vrammap++ = &vram[0x4000];
+ *vrammap++ = &vram[0x8000];
+ *vrammap++ = &vram[0xC000];
+ *vrammap++ = &vram[0x0000];
+ *vrammap++ = &vram[0x4000];
+ *vrammap++ = &vram[0x8000];
+ *vrammap = &vram[0xC000];
+ }
+ }
+}
+
+void MapVRAM_FG(u32 bank, u8 cnt)
+{
+ u8 oldcnt = VRAMCNT[bank];
+ VRAMCNT[bank] = cnt;
+
+ if (oldcnt == cnt) return;
+
+ u8 oldofs = (oldcnt >> 3) & 0x7;
+ u8 ofs = (cnt >> 3) & 0x7;
+
+ u8* vram = VRAM[bank];
+ bank -= 5;
+
+ if (oldcnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (oldcnt & 0x7)
+ {
+ case 0:
+ VRAM_LCD[0x24 + bank] = NULL;
+ break;
+
+ case 1:
+ vrammap = &VRAM_ABG[(oldofs & 0x1) | ((oldofs & 0x2) << 1)];
+ break;
+
+ case 2:
+ vrammap = &VRAM_AOBJ[(oldofs & 0x1) | ((oldofs & 0x2) << 1)];
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+
+ case 4:
+ // BG EXTPAL TODO
+ break;
+
+ case 5:
+ // OBJ EXTPAL TODO
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap = NULL;
+ }
+ }
+
+ if (cnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (cnt & 0x7)
+ {
+ case 0:
+ VRAM_LCD[0x24 + bank] = vram;
+ break;
+
+ case 1:
+ vrammap = &VRAM_ABG[(ofs & 0x1) | ((ofs & 0x2) << 1)];
+ break;
+
+ case 2:
+ vrammap = &VRAM_AOBJ[(ofs & 0x1) | ((ofs & 0x2) << 1)];
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+
+ case 4:
+ // BG EXTPAL TODO
+ break;
+
+ case 5:
+ // OBJ EXTPAL TODO
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap = vram;
+ }
+ }
+}
+
+void MapVRAM_H(u32 bank, u8 cnt)
+{
+ u8 oldcnt = VRAMCNT[bank];
+ VRAMCNT[bank] = cnt;
+
+ if (oldcnt == cnt) return;
+
+ u8 oldofs = (oldcnt >> 3) & 0x7;
+ u8 ofs = (cnt >> 3) & 0x7;
+
+ u8* vram = VRAM[bank];
+
+ if (oldcnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (oldcnt & 0x3)
+ {
+ case 0:
+ VRAM_LCD[0x26] = NULL;
+ VRAM_LCD[0x27] = NULL;
+ break;
+
+ case 1:
+ vrammap = &VRAM_BBG[0x00];
+ break;
+
+ case 2:
+ // BG EXTPAL TODO
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap = NULL;
+ }
+ }
+
+ if (cnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (cnt & 0x3)
+ {
+ case 0:
+ VRAM_LCD[0x26] = &vram[0x0000];
+ VRAM_LCD[0x27] = &vram[0x4000];
+ break;
+
+ case 1:
+ vrammap = &VRAM_BBG[0x00];
+ break;
+
+ case 2:
+ // BG EXTPAL TODO
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = &vram[0x0000];
+ *vrammap++ = &vram[0x4000];
+ *vrammap++ = &vram[0x0000];
+ *vrammap++ = &vram[0x4000];
+ *vrammap++ = &vram[0x0000];
+ *vrammap++ = &vram[0x4000];
+ *vrammap++ = &vram[0x0000];
+ *vrammap = &vram[0x4000];
+ }
+ }
+}
+
+void MapVRAM_I(u32 bank, u8 cnt)
+{
+ u8 oldcnt = VRAMCNT[bank];
+ VRAMCNT[bank] = cnt;
+
+ if (oldcnt == cnt) return;
+
+ u8 oldofs = (oldcnt >> 3) & 0x7;
+ u8 ofs = (cnt >> 3) & 0x7;
+
+ u8* vram = VRAM[bank];
+ bank -= 5;
+
+ if (oldcnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (oldcnt & 0x3)
+ {
+ case 0:
+ VRAM_LCD[0x28] = NULL;
+ break;
+
+ case 1:
+ vrammap = &VRAM_BBG[0x02];
+ break;
+
+ case 2:
+ vrammap = &VRAM_BOBJ[0x00];
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap++ = NULL;
+ *vrammap = NULL;
+ }
+ }
+
+ if (cnt & (1<<7))
+ {
+ u8** vrammap = NULL;
+
+ switch (cnt & 0x3)
+ {
+ case 0:
+ VRAM_LCD[0x28] = vram;
+ break;
+
+ case 1:
+ vrammap = &VRAM_BBG[0x02];
+ break;
+
+ case 2:
+ vrammap = &VRAM_BOBJ[0x00];
+ break;
+
+ case 3:
+ // not mapped to memory
+ break;
+ }
+
+ if (vrammap)
+ {
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap++ = vram;
+ *vrammap = vram;
+ }
+ }
+}
+
+
+void DrawScanline(u32 screen, u32 line)
+{
+ u16* dst = &Framebuffer[256 * ((192*screen) + line)];
+
+ if (screen==0)
+ {
+ u16* src = &((u16*)VRAM_A)[256*line];
+ for (int i = 0; i < 256; i++)
+ dst[i] = src[i];
+ }
+ else
+ {
+ for (int i = 0; i < 256; i++)
+ dst[i] = 0x7FFF;
+ }
+}
+
+
+void StartFrame()
+{
+ StartScanline(0);
+}
+
+void StartScanline(u32 line)
+{
+ VCount = line;
+
+ if (line == VMatch[0])
+ {
+ DispStat[0] |= (1<<2);
+
+ if (DispStat[0] & (1<<5)) NDS::TriggerIRQ(0, NDS::IRQ_VCount);
+ }
+ else
+ DispStat[0] &= ~(1<<2);
+
+ if (line == VMatch[1])
+ {
+ DispStat[1] |= (1<<2);
+
+ if (DispStat[1] & (1<<5)) NDS::TriggerIRQ(1, NDS::IRQ_VCount);
+ }
+ else
+ DispStat[1] &= ~(1<<2);
+
+ if (line < 192)
+ {
+ // draw
+ DrawScanline(0, line);
+ DrawScanline(1, line);
+
+ NDS::ScheduleEvent(LINE_CYCLES, StartScanline, line+1);
+ }
+ else if (line == 262)
+ {
+ // frame end
+
+ DispStat[0] &= ~(1<<0);
+ DispStat[1] &= ~(1<<0);
+ }
+ else
+ {
+ if (line == 192)
+ {
+ // VBlank
+ DispStat[0] |= (1<<0);
+ DispStat[1] |= (1<<0);
+
+ if (DispStat[0] & (1<<3)) NDS::TriggerIRQ(0, NDS::IRQ_VBlank);
+ if (DispStat[1] & (1<<3)) NDS::TriggerIRQ(1, NDS::IRQ_VBlank);
+ }
+
+ NDS::ScheduleEvent(LINE_CYCLES, StartScanline, line+1);
+ }
+}
+
+
+void SetDispStat(u32 cpu, u16 val)
+{
+ val &= 0xFFB8;
+ DispStat[cpu] &= 0x0047;
+ DispStat[cpu] |= val;
+
+ VMatch[cpu] = (val >> 8) | ((val & 0x80) << 1);
+
+ if (val & 0x10) printf("!! HBLANK ENABLED\n");
+}
+
+}