//
// Screen Handler
//
-// This sets screen to VESA 320x240 LFB so we can use the WHOLE laptop screen
-// Now with VESA2 support!
-// Also, support routines for video hardware emulation are included
+// This emulates the NAMCO tile/sprite hardware
//
// by James Hammons
-//
// (C) 2003 Underground Software
//
// JLH = James Hammons <jlhamm@acm.org>
void DrawSprites(uint8_t priority);
int FindPCXName(void);
-//static void DrawChar(uint8_t * chr, uint8_t * ram, uint8_t sx, uint8_t sy, uint16_t scp, uint32_t baseAddr, uint32_t scrollOffset, bool transparent = true);
-static void DrawChar(uint8_t * chr, uint8_t * ram, uint8_t sx, uint8_t sy, uint16_t scp, uint32_t baseAddr, uint32_t xScroll = 0, uint32_t yScroll = 0, bool transparent = true);
+static inline void DrawScreen(uint16_t ramBlock, uint16_t xAddress, uint16_t yAddress, uint32_t baseAddr, bool transparent = true);
+static void DrawChar(uint8_t sx, uint8_t sy, uint16_t scp, uint32_t baseAddr, uint32_t xScroll, uint32_t yScroll, bool transparent = true);
void Sprite(uint32_t sprnum, uint16_t x, uint16_t y, uint8_t flip, uint8_t horiz_bl, uint8_t vert_bl);
// Private global variables
-uint8_t my_scr[0x14000]; // Screen buffer...
-//uint8_t palette[768]; // Screen palette
-uint32_t palette[256]; // Screen palette
-uint8_t ccolor[256][8]; // Character colors
-uint8_t scolor[128][16]; // Sprite colors
-bool charbase; // Character base pointer...
-uint8_t hScrollOffset; // Horizontal scroll offset
-uint8_t vScrollOffset; // Vertical scroll offset
-uint8_t spr_color_index; // Sprite color index
-//uint32_t hoffsets[8] = { 0, 1, 2, 3, 4, 5, 6, 7 };// Scroll offsets...
-//uint32_t voffsets[8] = { 0, 320, 640, 960, 1280, 1600, 1920, 2240 };
-uint32_t voffsets[8] = { 288*0, 288*1, 288*2, 288*3, 288*4, 288*5, 288*6, 288*7 };
+uint8_t my_scr[0x14000]; // Screen buffer...
+uint32_t palette[256]; // Screen palette
+uint8_t ccolor[256][8]; // Character colors
+uint8_t scolor[128][16]; // Sprite colors
+bool charBankSwitch; // Character bank switch
+uint8_t spr_color_index; // Sprite color index
-extern bool show_text; // Whether or not to show text
-extern bool show_scr; // Whether or not to show screen
+extern bool show_text; // Whether or not to show text
//
// Render the NAMCO screen
//
-void BlitChar(SDL_Surface * scr, uint8_t * chr, uint8_t * ram)
+void BlitChar(uint8_t * chr, uint8_t * ram)
{
// Screen structure:
+ //
+ // Each screen RAM is 4K in size, from lowest to highest priority:
+ // $0000-$0FFF, $1000-$1FFF, $2000-$2FFF, $3000-$3FFF
+ //
// Screen is 288 x 224 pixels, with character and independent sprites.
- // Tiles are 36 x 28. There are four tile planes, three of them affected by
- // the h/vscroll values, the last one is a static display (also has highest
- // priority). Screens are 128 bytes wide by 32 bytes high.
-
- if (show_scr)
- {
- uint32_t sc_base = ((ram[0x9000] << 8) | ram[0x9001]) + 4; // Adjust hscroll val
- hScrollOffset = sc_base & 0x07; // Horiz. fine scroll offset
- sc_base = (sc_base & 0xFFF8) >> 2; // Skip odds..
- uint8_t vsc_base = ((ram[0x9002] + 1) & 0xF8) >> 3;// Vertical scroll addr adjust
- vScrollOffset = ((ram[0x9002] + 1) & 0x07); // Vertical fine scroll amount
-
- uint32_t scp0 = 0x0180 | ((sc_base + 0x04) & 0x7F); /*0x0188;*/
- uint32_t scp1 = 0x1180 | ((sc_base + 0x04) & 0x7F); /*0x1188;*/
- uint32_t scp2 = 0x2180 | ((sc_base + 0x04) & 0x7F); /*0x2188;*/
- uint32_t scp3 = 0x3208;
-
- scp0 += vsc_base * 0x80;
- scp0 &= 0x0FFF; // Set vertical scroll addr
- scp1 += vsc_base * 0x80;
- scp1 = 0x1000 | (scp1 & 0x0FFF); // Set vertical scroll addr
- scp2 += vsc_base * 0x80;
- scp2 = 0x2000 | (scp2 & 0x0FFF); // Set vertical scroll addr
-
- // Layer 0 (bottom layer)
- for(uint8_t sy=0; sy<29; sy++)
- {
- for(uint8_t sx=0; sx<37; sx++)
- DrawChar(chr, ram, sx, sy, scp0, (charbase ? 0x20000 : 0x00000), hScrollOffset, vScrollOffset, false);
-
- scp0 += 0x80;
- scp0 = 0x0000 | (scp0 & 0x0FFF);
- }
-
- // Draw sprites at lowest layer...
- DrawSprites(0x40);
-
- // Layer 1
- for(uint8_t sy=0; sy<29; sy++)
- {
- for(uint8_t sx=0; sx<37; sx++)
- DrawChar(chr, ram, sx, sy, scp1, (charbase ? 0x30000 : 0x10000), hScrollOffset, vScrollOffset);
-
- scp1 += 0x80;
- scp1 = 0x1000 | (scp1 & 0x0FFF);
- }
-
- // Draw sprites under layer #2...
- DrawSprites(0x80);
-
- // Layer 2
- for(uint8_t sy=0; sy<29; sy++)
- {
- for(uint8_t sx=0; sx<37; sx++)
- DrawChar(chr, ram, sx, sy, scp2, 0x40000, hScrollOffset, vScrollOffset);
-
- scp2 += 0x80;
- scp2 = 0x2000 | (scp2 & 0x0FFF);
- }
-
- // Draw highest priority sprites...
- DrawSprites(0xC0);
-
- // Layer 3 (top layer)
- for(uint8_t sy=0; sy<28; sy++)
- {
- for(uint8_t sx=0; sx<36; sx++)
- DrawChar(chr, ram, sx, sy, scp3, 0x50000);
-
- scp3 += 0x80;
- }
- }
+ // Tiles are 36 x 28. There are four tile planes, all of them affected by
+ // their own h/vscroll values. Screens are 128 bytes wide by 32 bytes high.
+ //
+ // Also note that tiles are 16-bits wide, meaning the screen is really
+ // only 64 characters wide!
+
+ // Base address is $9000-1 (top 13 bits) + $9002 >> 3 << 7 (top 5 bits)
+/*
+$9000-2: $02 $0C $FF 0000 0010 0000 1100 1111 1111
+$9004-6: $06 $0E $FF 0000 0110 0000 1110 1111 1111
+$9400-2: $0A $0B $FF 0000 1010 0000 1011 1111 1111
+$9404-6: $0E $0D $07 0000 1110 0000 1101 0000 0111
+ ---- PP?H HHHH Hhhh VVVV Vvvv
+? = refresh layer bit?
+PP = which 4K block to write to?
+*/
+ uint16_t screenX0 = (((ram[0x9000] << 8) | ram[0x9001]) + 20) & 0x1FF;
+ uint16_t screenX1 = (((ram[0x9004] << 8) | ram[0x9005]) + 18) & 0x1FF;
+ uint16_t screenX2 = (((ram[0x9400] << 8) | ram[0x9401]) + 21) & 0x1FF;
+ uint16_t screenX3 = (((ram[0x9404] << 8) | ram[0x9405]) + 19) & 0x1FF;
+
+ uint16_t screenY0 = ram[0x9002] + 25;
+ uint16_t screenY1 = ram[0x9006] + 25;
+ uint16_t screenY2 = ram[0x9402] + 25;
+ uint16_t screenY3 = ram[0x9406] + 25;
+
+ uint16_t ramBlock0 = (ram[0x9000] >> 2) & 0x03;
+ uint16_t ramBlock1 = (ram[0x9004] >> 2) & 0x03;
+ uint16_t ramBlock2 = (ram[0x9400] >> 2) & 0x03;
+ uint16_t ramBlock3 = (ram[0x9404] >> 2) & 0x03;
+
+ DrawScreen(ramBlock0, screenX0, screenY0, (charBankSwitch ? 2 : 0), false);
+ DrawSprites(0x40);
+ DrawScreen(ramBlock1, screenX1, screenY1, (charBankSwitch ? 3 : 1));
+ DrawSprites(0x80);
+ DrawScreen(ramBlock2, screenX2, screenY2, 4);
+ DrawSprites(0xC0);
+ DrawScreen(ramBlock3, screenX3, screenY3, 5);
// Draw a msg if needed...
if (show_text)
// Rolling Thunder screen size is 288 x 224. Virtual is this, real may not
// be... (and we don't have to care about that, the OpenGL backend takes
// care of it.)
+ for(uint32_t i=0; i<VIRTUAL_SCREEN_WIDTH*VIRTUAL_SCREEN_HEIGHT; i++)
+ scrBuffer[i] = palette[my_scr[i]];
+
+ RenderScreenBuffer();
+}
+
- uint32_t src = 0;
+//
+// Render tilemap
+//
+static inline void DrawScreen(uint16_t ramBlock, uint16_t xAddress, uint16_t yAddress, uint32_t tileBase, bool transparent/*= true*/)
+{
+ uint16_t ramBase = (ramBlock << 12) | ((yAddress << 4) & 0xF80)
+ | ((xAddress >> 2) & 0x7E);
- for(int i=0; i<VIRTUAL_SCREEN_HEIGHT; i++)
+ for(uint8_t sy=0; sy<29; sy++)
{
- for (int j=0; j<VIRTUAL_SCREEN_WIDTH; j++)
+ for(uint8_t sx=0; sx<37; sx++)
{
- scrBuffer[src] = palette[my_scr[src]];
- src++;
+
+ DrawChar(sx, sy, ramBase, tileBase << 16, xAddress & 0x07, yAddress & 0x07, transparent);
}
}
-
- RenderScreenBuffer();
}
//
// Draw character on screen
//
-//static inline void DrawChar(uint8_t * chr, uint8_t * ram, uint8_t sx, uint8_t sy, uint16_t scp, uint32_t baseAddr, uint32_t scrollOffset, bool transparent/*= true*/)
-static inline void DrawChar(uint8_t * chr, uint8_t * ram, uint8_t sx, uint8_t sy, uint16_t scp, uint32_t baseAddr, uint32_t xScroll/*= 0*/, uint32_t yScroll/*= 0*/, bool transparent/*= true*/)
+static inline void DrawChar(uint8_t sx, uint8_t sy, uint16_t ramBase, uint32_t tileBase, uint32_t xScroll, uint32_t yScroll, bool transparent/*= true*/)
{
- uint8_t scp_lo = (scp + (sx << 1)) & 0x7F;// Let LO byte wrap only...
- uint16_t sp2 = (scp & 0xFF80) | scp_lo;
- uint8_t tile = ram[sp2++];
- uint8_t index = ram[sp2] & 0x03;
- uint8_t color = ram[sp2];
- uint32_t chind = baseAddr + (((index << 8) + tile) * 64);
+ extern uint8_t charROM[];
+ extern uint8_t gram1[];
+
+ // Calculate address in RAM of tile to draw
+ uint16_t addr = (ramBase & 0xF000) | ((ramBase + (sy << 7)) & 0x0F80)
+ | ((ramBase + (sx << 1)) & 0x7F);
+ uint16_t tile = ((gram1[addr + 1] << 8) | gram1[addr]) & 0x03FF;
+ // Yes, it really requires all 8 bits... even though the bottom 3 are used
+ // as a tile address!
+ uint8_t color = gram1[addr + 1];
+ uint32_t chind = tileBase + (tile << 6);
+
int xStart = (int)(sx * 8) - xScroll;
int yStart = (int)(sy * 8) - yScroll;
int32_t sc_addr = xStart + (yStart * 288);
{
for(int x=0; x<8; x++)
{
+ // Clipping...
if (((xStart + x) < 0) || ((xStart + x) >= 288)
|| ((yStart + y) < 0) || ((yStart + y) >= 224))
{
continue;
}
- if (transparent)
- {
- if (chr[chind] != 7)
- my_scr[sc_addr] = ccolor[color][chr[chind]];
- }
- else
- my_scr[sc_addr] = ccolor[color][chr[chind]];
+ if (!(transparent && (charROM[chind] == 7)))
+ my_scr[sc_addr] = ccolor[color][charROM[chind]];
sc_addr++;
chind++;
}
+//
+// Copy sprites in sprite RAM from positions 4-9 to 10-15
+// (N.B.: This still doesn't solve the shifting signs on the walls problem...)
+//
+void CopySprites(void)
+{
+ extern uint8_t gram1[];
+
+ for(uint16_t i=0x5800; i<0x6000; i+=0x10)
+ {
+ for(uint16_t j=4; j<=9; j++)
+ {
+ gram1[i + j + 6] = gram1[i + j];
+ }
+ }
+}
+
+
//
// Draw sprites at priority level (new code)
//
for(uint16_t i=0x5800; i<0x6000; i+=0x10)
{
- if ((gram1[i + 8] & 0xC0) == priority) // Check for correct layer...
+ if ((gram1[i + 8 + 6] & 0xC0) == priority) // Check for correct layer...
{
- spr_color_index = gram1[i + 6] >> 1; // Set color...
- uint16_t x = ((gram1[i + 6] & 0x01) << 8) | gram1[i + 7];
+ spr_color_index = gram1[i + 6 + 6] >> 1; // Set color...
+ uint16_t x = ((gram1[i + 6 + 6] & 0x01) << 8) | gram1[i + 7 + 6];
if (x > 512 - 32)
x -= 512; // Handle neg x values
- uint16_t y = 192 - gram1[i + 9];
- uint8_t flip = gram1[i + 4] & 0x20; // Horizontal flip
- uint32_t spr_num = ((gram1[i + 4] & 0x07) << 9)
- | ((gram1[i + 5] & 0x7F) << 2)
- | ((gram1[i + 4] & 0x10) >> 4)
- | ((gram1[i + 8] & 0x10) >> 3);
+ uint16_t y = 192 - gram1[i + 9 + 6];
+ uint8_t flip = gram1[i + 4 + 6] & 0x20; // Horizontal flip
+ uint32_t spr_num = ((gram1[i + 4 + 6] & 0x07) << 9)
+ | ((gram1[i + 5 + 6] & 0x7F) << 2)
+ | ((gram1[i + 4 + 6] & 0x10) >> 4)
+ | ((gram1[i + 8 + 6] & 0x10) >> 3);
// Draw sprite...
- Sprite(spr_num, x, y, flip, gram1[i + 4] & 0x80, gram1[i + 8] & 0x04);
+ Sprite(spr_num, x, y, flip, gram1[i + 4 + 6] & 0x80, gram1[i + 8 + 6] & 0x04);
}
}
}
projects / thunder / blobdiff