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@@ -23,8 +23,6 @@
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#define screenHeight 240
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#define texWidth 64
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#define texHeight 64
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-
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-// Map
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#define mapWidth 24
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#define mapHeight 24
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@@ -85,34 +83,37 @@ word worldMap[mapWidth][mapHeight] = {
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{4, 0, 0, 0, 0, 0, 0, 0, 0, 4, 6, 0, 6, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2},
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{4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3}};
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+
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// Global variables, so render function can access it
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word drawStart = 0;
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word drawEnd = 0;
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word texNum = 0;
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word side = 0; // was a NorthSouth or a EastWest wall hit?
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-// Render vertical line in pixel plane with textures
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-// INPUT:
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-// r1 first pixel addr VRAM addr of first pixel in line (top pixel)
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-// r2 (a2r) drawStart Starting pixel of wall
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-// r3 (a2r) drawEnd Ending pixel of wall
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-// r4 texPos Starting texture coordinate
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-// r5 step How much to increase the texture coordinate per screen pixel
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-// r6 texX X coordinate on the texture
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-// r7 x X position of line to render
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-// r8 current FB pos Current framebuffer position in VRAM (top to bottom)
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-// r9 end loop FB pos Last framebuffer position in VRAM of current loop
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-// r10 texY Y coordinate on the texture
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-// r11 gp Used as temp reg in calculations
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-// r12 texture[texNum] Texture array of texture to draw
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-// r13 color Pixel color
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-// r14 ceil or floor col Ceiling or floor color
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-// r15 side North South or East West wall side
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-void RAYFX_drawTextureVertLine(fixed_point_t texPos, fixed_point_t step, word texX, word x)
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+// Globalr vars
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+// x and y start position
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+fixed_point_t RAY_posX;
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+fixed_point_t RAY_posY;
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+
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+// initial direction vector
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+fixed_point_t RAY_dirX;
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+fixed_point_t RAY_dirY;
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+
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+// the 2d raycaster version of camera plane
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+fixed_point_t RAY_planeX;
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+fixed_point_t RAY_planeY;
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+
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+// Local vars to store
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+
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+
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+// Render entire screen
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+// Registers (global):
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+// r1 x current vertical line (x of screen)
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+void RAYFX_renderScreen()
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{
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// reg 4 5 6 7 (args) and 2 3 (retval) are safe
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asm(
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- "; backup registers\n"
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+ // backdup registers
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"push r1\n"
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"push r8\n"
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"push r9\n"
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@@ -124,93 +125,411 @@ void RAYFX_drawTextureVertLine(fixed_point_t texPos, fixed_point_t step, word te
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"push r15\n"
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);
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- // setup registers
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asm(
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- "addr2reg drawStart r2 ; r2 = drawStart addr\n"
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- "read 0 r2 r2 ; r2 = drawStart value\n"
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+
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+ // r1: current vertical line (x of screen)
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+ "load32 0 r1\n"
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+
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+ // for each vertical line (x)
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+ "RAYFX_screenXloop:\n"
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+
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+ // cameraX
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+ "addr2reg LUTcameraX r15\n" // r15 = LUTcameraX
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+ "add r15 r1 r15\n" // r15 = LUTcameraX[x] addr
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+ "read 0 r15 r15\n" // r15 = LUTcameraX[x] value
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+
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+ // r2 rayDirx [FP] x dir of ray
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+ // r3 rayDiry [FP] y dir of ray
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+
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+ // r2: rayDirX
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+ "addr2reg RAY_dirX r14\n" // r14 = RAY_dirX addr
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+ "read 0 r14 r14\n" // r14 = RAY_dirX value
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+ "addr2reg RAY_planeX r13\n" // r13 = RAY_planeX addr
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+ "read 0 r13 r13\n" // r13 = RAY_planeX value
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+ "multfp r13 r15 r2\n" // r2 = FP_Mult(RAY_planeX, cameraX)
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+ "add r2 r14 r2\n" // r2 += RAY_dirX
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+
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+ // r3: rayDirY
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+ "addr2reg RAY_dirY r14\n" // r14 = RAY_dirY addr
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+ "read 0 r14 r14\n" // r14 = RAY_dirY value
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+ "addr2reg RAY_planeY r13\n" // r13 = RAY_planeY addr
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+ "read 0 r13 r13\n" // r13 = RAY_planeY value
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+ "multfp r13 r15 r3\n" // r3 = FP_Mult(RAY_planeY, cameraX)
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+ "add r3 r14 r3\n" // r3 += RAY_dirY
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+
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+ // r4: deltaDistX
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+ "load32 1 r15\n" // r15 = 1
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+ "shiftl r15 16 r15\n" // r15 = FP(1)
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+ "load32 0xC02742 r14\n" // r14 = addr fpdiv_writea
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+ "write 0 r14 r15\n" // write a (fp1) to divider
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+ "write 1 r14 r2\n" // write b (rayDirX) to divider and perform division
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+ "read 1 r14 r4\n" // read result to r4
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+ "shiftrs r4 31 r13\n" // r13 = y = x >>(signed) 31 (start of abs)
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+ "xor r4 r13 r4\n" // r4 = (x ^ y)
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+ "sub r4 r13 r4\n" // r4 -= y (result of abs)
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+
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+ // r5: deltaDistY (uses r14 and r15 from above)
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+ "write 0 r14 r15\n" // write a (fp1) to divider
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+ "write 1 r14 r3\n" // write b (rayDirY) to divider and perform division
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+ "read 1 r14 r5\n" // read result to r5
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+ "shiftrs r5 31 r13\n" // r13 = y = x >>(signed) 31 (start of abs)
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+ "xor r5 r13 r5\n" // r5 = (x ^ y)
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+ "sub r5 r13 r5\n" // r5 -= y (result of abs)
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+
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+ // if (rayDirX < 0), else
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+ // r6: stepX
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+ // r7: stepY
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+ // r8: sideDistX
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+ // r9: sideDistY
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+ // r10: mapX
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+ // r11: mapY
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+ "blts r2 r0 2\n" // if (rayDirX < 0) skip next line
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+ "jump RAYFX_rayDirXge0\n" // goto RAYFX_rayDirXge0
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+
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+ "load32 -1 r6\n" // r6 = stepX = -1
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+ "addr2reg RAY_posX r15\n" // r15 = RAY_posX addr
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+ "read 0 r15 r15\n" // r15 = RAY_posX value
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+ "shiftrs r15 16 r10\n" // mapX = int(RAY_posX)
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+ "load32 0xFFFF r14\n" // r14 = decimal part mask
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+ "and r15 r14 r15\n" // r15 = RAY_posX decimal part
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+ "multfp r15 r4 r8\n" // sideDistX = RAY_posX decimal part * deltaDistX
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+ "jump RAYFX_rayDirXltEnd\n" // skip the else part
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+
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+ "RAYFX_rayDirXge0:\n"
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+ "load32 1 r6\n" // stepX = 1
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+ "addr2reg RAY_posX r15\n" // r15 = RAY_posX addr
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+ "read 0 r15 r15\n" // r15 = RAY_posX value
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+ "shiftrs r15 16 r10\n" // r10 (mapX) = r15 >> 16 (to int)
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+ "add r10 1 r14\n" // r14 = int(RAY_posX) + 1
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+ "shiftl r14 16 r14\n" // r14 <<=16 (to FP)
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+ "sub r14 r15 r15\n" // r15 = r14 - RAY_posX
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+ "multfp r15 r4 r8\n" // sideDistX = RAY_posX-ish * deltaDistX
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+
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+ "RAYFX_rayDirXltEnd:\n"
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+
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+ // if (rayDirY < 0), else
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+ "blts r3 r0 2\n" // if (rayDirY < 0) skip next line
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+ "jump RAYFX_rayDirYge0\n" // goto RAYFX_rayDirYge0
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+
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+ "load32 -1 r7\n" // r7 = stepY = -1
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+ "addr2reg RAY_posY r15\n" // r15 = RAY_posY addr
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+ "read 0 r15 r15\n" // r15 = RAY_posY value
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+ "shiftrs r15 16 r11\n" // mapY = int(RAY_posY)
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+ "load32 0xFFFF r14\n" // r14 = decimal part mask
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+ "and r15 r14 r15\n" // r15 = RAY_posY decimal part
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+ "multfp r15 r5 r9\n" // sideDistY = RAY_posY decimal part * deltaDistY
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+ "jump RAYFX_rayDirYltEnd\n" // skip the else part
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+
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+ "RAYFX_rayDirYge0:\n"
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+ "load32 1 r7\n" // stepY = 1
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+ "addr2reg RAY_posY r15\n" // r15 = RAY_posY addr
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+ "read 0 r15 r15\n" // r15 = RAY_posY value
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+ "shiftrs r15 16 r11\n" // r11 (mapY) = r15 >> 16 (to int)
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+ "add r11 1 r14\n" // r14 = int(RAY_posY) + 1
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+ "shiftl r14 16 r14\n" // r14 <<=16 (to FP)
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+ "sub r14 r15 r15\n" // r15 = r14 - RAY_posX
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+ "multfp r15 r5 r9\n" // sideDistY = RAY_posX-ish * deltaDistY
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+
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+ "RAYFX_rayDirYltEnd:\n"
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+
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+ // DDA (uses tmp r15)
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+ "load32 0 r15\n" // hit = 0
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+ "RAYFX_DDAwhileNoHit:\n" // while (hit == 0)
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+ "beq r15 r0 2\n" // while check
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+ "jump RAYFX_DDAwhileNoHitDone\n"
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+
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+ // if (sideDistX < sideDistY), else
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+ "blts r8 r9 2\n" // if (sideDistX < sideDistY) skip next line
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+ "jump RAYFX_sideDistXltY\n" // goto RAYFX_sideDistXltY
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+
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+ "add r8 r4 r8\n" // sideDistX += deltaDistX;
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+ "add r10 r6 r10\n" // mapX += stepX;
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+ "addr2reg side r14\n" // side;
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+ "write 0 r14 r0\n" // side = 0;
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+ "jump RAYFX_sideDistXltYend\n" // skip the else part
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+
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+ "RAYFX_sideDistXltY:\n"
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+ "add r9 r5 r9\n" // sideDistY += deltaDistY;
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+ "add r11 r7 r11\n" // mapY += stepY;
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+ "addr2reg side r14\n" // side;
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+ "load32 1 r13\n" // 1
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+ "write 0 r14 r13\n" // side = 1;
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+
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+ "RAYFX_sideDistXltYend:\n"
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+
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+ "addr2reg worldMap r14\n" // r14 = worldMap addr;
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+ "multu r10 24 r13\n" // r13 = mapX offset using mapHeight
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+ "add r13 r11 r13\n" // r13 += mapY offset
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+ "add r13 r14 r14\n" // r14 = worldMap[mapX][mapY] addr
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+ "read 0 r14 r14\n" // r14 = worldMap[mapX][mapY] value
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+ "bles r14 r0 2\n" // skip next instruction if worldMap[mapX][mapY] <= 0
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+ "load 1 r15\n" // hit = 1
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+
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+ "jump RAYFX_DDAwhileNoHit\n" // return to while loop start
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+
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+ "RAYFX_DDAwhileNoHitDone:\n"
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+
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+ // From this point, r10 r11 mapx mapy (and r15) are free
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+
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+ // texNum = worldMap[mapX][mapY] - 1;
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+ // assumes worldMap[mapX][mapY] value is still in r14
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+ "addr2reg texNum r13\n" // r13 = texNum addr;
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+ "sub r14 1 r14\n" // r14 = worldMap[mapX][mapY] - 1
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+ "write 0 r13 r14\n" // write texNum;
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+
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+ // r10: perpWallDist (FP)
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+ "addr2reg side r15\n" // side addr
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+ "read 0 r15 r15\n" // side value
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+
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+ // if (side == 0), else
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+ "bne r15 r0 3\n" // if (side != 0) skip next two lines
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+ "sub r8 r4 r10\n" // perpWallDist = (sideDistX - deltaDistX); (match)
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+ "jumpo 2\n" // skip else part
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+ "sub r9 r5 r10\n" // perpWallDist = (sideDistY - deltaDistY); (else)
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+
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+ // From this point sideDistX&Y and deltaDistX&Y are free
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+ // this frees up regs 4 5 8 and 9
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+ // leaving to use: 4, 5, 8, 9, 11, 12, 13, 14, 15
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+
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+ // r4: lineHeight
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+ "load32 240 r15\n" // r15 = screenHeight
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+ "shiftl r15 16 r15\n" // r15 = FP(screenHeight)
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+ "load32 0xC02742 r14\n" // r14 = addr fpdiv_writea
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+ "write 0 r14 r15\n" // write a (FP(screenHeight) to divider
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+ "write 1 r14 r10\n" // write b (perpWallDist) to divider and perform division
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+ "read 1 r14 r4\n" // read result to r4
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+ "shiftrs r4 16 r4\n" // r4 = lineHeight = int(r4)
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+
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+ "shiftrs r4 1 r15\n" // r15 = lineHeight >> 1
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+ "load32 -1 r14\n" // r14 = -1
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+ "mults r15 r14 r15\n" // r15 = -r15
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+ "load32 120 r14\n" // r14 = screenHeight >> 1
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+ "add r14 r15 r15\n" // r15 = drawStart value (r14+r15)
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+ "bges r15 r0 2\n" // skip next line if drawStart >= 0
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+ "load 0 r15\n" // set drawStart to 0 if < 0
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+ "addr2reg drawStart r14\n" // r14 = drawStart addr
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+ "write 0 r14 r15\n" // write drawStart value
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+
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+ // skip render if start > 238
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+ "load32 238 r14\n"
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+ "blts r15 r14 2 \n"
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+ "jump RAYFX_skipRenderLine\n"
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+
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+ "shiftrs r4 1 r15\n" // r15 = lineHeight >> 1
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+ "load32 120 r14\n" // r14 = screenHeight >> 1
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+ "add r14 r15 r15\n" // r15 = drawEnd value (r14+r15)
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+ "load32 240 r14\n" // r14 = screenHeight
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+ "blts r15 r14 2\n" // skip next line if drawEnd < screenHeight
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+ "load 239 r15\n" // set drawEnd to screenHeight - 1
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+ "addr2reg drawEnd r14\n" // r14 = drawEnd addr
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+ "write 0 r14 r15\n" // write drawEnd value
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+
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+
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+ // texture calculations
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+ // r8: side
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+ // r5: wallX
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+ "addr2reg side r8\n" // r8 = side addr
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+ "read 0 r8 r8\n" // r8 = side value
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+ "bne r8 r0 7\n" // if side != 0, goto else part (addr2reg is two instructions!)
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+ "addr2reg RAY_posY r15\n" // r15 = RAY_posY addr
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+ "read 0 r15 r15\n" // r15 = RAY_posY value
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+ "multfp r10 r3 r14\n" // r14 = perpWallDist * rayDirY
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+ "add r14 r15 r5\n" // r5 = wallX = r14 + RAY_posY
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+ "jumpo 5\n" // skip else
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+
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+ // else
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+ "addr2reg RAY_posX r15\n" // r15 = RAY_posX addr
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+ "read 0 r15 r15\n" // r15 = RAY_posX value
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+ "multfp r10 r2 r14\n" // r14 = perpWallDist, rayDirX
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+ "add r14 r15 r5\n" // r5 = wallX = r14 + RAY_posX
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+
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+ "load32 0xFFFF r15\n" // r15 = floormask
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+ "and r5 r15 r5\n" // wallX-=floor(wallX)
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+
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+ // r6: texX
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+ "load32 64 r15\n" // r15 = texWidth
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+ "shiftl r15 16 r14\n" // r14 = FP(texWidth)
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+ "multfp r14 r5 r6\n" // r6 = FP_Mult(wallX, FP_intToFP(texWidth))
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+ "shiftrs r6 16 r6\n" // r6 = int(r6)
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+
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+ "bne r8 r0 4\n" // skip if side != 0
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+ "bles r2 r0 3\n" // skip if rayDirX <= 0
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+
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+ "sub r15 r6 r6\n" // texX = texWidth - texX
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+ "sub r6 1 r6\n" // texX -= 1
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+
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+ "beq r8 r0 4\n" // skip if side == 0
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+ "bges r3 r0 3\n" // skip if rayDirY >= 0
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+
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+ "sub r15 r6 r6\n" // texX = texWidth - texX
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+ "sub r6 1 r6\n" // texX -= 1
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+
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+ // r2 and r3 are free now (no rayDirX&Y needed)
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+ // r5: step
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+ "load32 64 r15\n" // r15 = texHeight
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+ "shiftl r15 16 r15\n" // r15 = FP(texHeight)
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+ "shiftl r4 16 r14\n" // r14 = FP(lineHeight)
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+ "load32 0xC02742 r13\n" // r13 = addr fpdiv_writea
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+ "write 0 r13 r15\n" // write a (FP(screenHeight) to divider
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+ "write 1 r13 r14\n" // write b (FP(lineHeight)) to divider and perform division
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+ "read 1 r13 r5\n" // read result to r5
|
|
|
+
|
|
|
+ // r4: texPos
|
|
|
+ "addr2reg drawStart r15\n" // r15 = drawStart addr
|
|
|
+ "read 0 r15 r15\n" // r15 = drawStart value
|
|
|
+ "sub r15 120 r15\n" // r15 -= (screenHeight >> 1)
|
|
|
+ "shiftrs r4 1 r14\n" // r14 = lineHeight >> 1
|
|
|
+ "add r15 r14 r15\n" // r15 += lineHeight >> 1
|
|
|
+ "shiftl r15 16 r15\n" // r15 = FP(r15)
|
|
|
+ "multfp r15 r5 r4\n" // r4 = r15 * step
|
|
|
+
|
|
|
+ "or r1 r0 r7\n" // move x to r7
|
|
|
+
|
|
|
+
|
|
|
+ // Render vertical line in pixel plane with textures
|
|
|
+ // Registers:
|
|
|
+ // r1 first pixel addr VRAM addr of first pixel in line (top pixel)
|
|
|
+ // r2 (a2r) drawStart Starting pixel of wall
|
|
|
+ // r3 (a2r) drawEnd Ending pixel of wall
|
|
|
+ // r4 texPos Starting texture coordinate
|
|
|
+ // r5 step How much to increase the texture coordinate per screen pixel
|
|
|
+ // r6 texX X coordinate on the texture
|
|
|
+ // r7 x X position of line to render
|
|
|
+ // r8 current FB pos Current framebuffer position in VRAM (top to bottom)
|
|
|
+ // r9 end loop FB pos Last framebuffer position in VRAM of current loop
|
|
|
+ // r10 texY Y coordinate on the texture
|
|
|
+ // r11 gp Used as temp reg in calculations
|
|
|
+ // r12 texture[texNum] Texture array of texture to draw
|
|
|
+ // r13 color Pixel color
|
|
|
+ // r14 ceil or floor col Ceiling or floor color
|
|
|
+ // r15 side North South or East West wall side
|
|
|
+
|
|
|
+ "push r1\n"
|
|
|
+ "push r2\n"
|
|
|
+ "push r3\n"
|
|
|
+ "push r4\n"
|
|
|
+ "push r5\n"
|
|
|
+ "push r6\n"
|
|
|
+ "push r7\n"
|
|
|
+ "push r8\n"
|
|
|
+ "push r9\n"
|
|
|
+ "push r10\n"
|
|
|
+ "push r11\n"
|
|
|
+ "push r12\n"
|
|
|
+ "push r13\n"
|
|
|
+ "push r14\n"
|
|
|
+ "push r15\n"
|
|
|
+
|
|
|
+ "addr2reg drawStart r2 ; r2 = drawStart addr\n"
|
|
|
+ "read 0 r2 r2 ; r2 = drawStart value\n"
|
|
|
+
|
|
|
+ "addr2reg drawEnd r3 ; r3 = drawEnd addr\n"
|
|
|
+ "read 0 r3 r3 ; r3 = drawEnd value\n"
|
|
|
+
|
|
|
+ "load32 0xD00000 r1 ; r1 = framebuffer addr\n"
|
|
|
+ "add r1 r7 r1 ; r1 = first pixel in line (fb+x)\n"
|
|
|
+
|
|
|
+ "or r0 r1 r8 ; r8 = current pixel\n"
|
|
|
+
|
|
|
+ "multu r2 320 r9 ; r9 = drawStart VRAM offset\n"
|
|
|
+ "add r9 r1 r9 ; r9 = last FB pos of before wall\n"
|
|
|
|
|
|
- "addr2reg drawEnd r3 ; r3 = drawEnd addr\n"
|
|
|
- "read 0 r3 r3 ; r3 = drawEnd value\n"
|
|
|
+ "addr2reg texNum r12 ; r12 = texNum addr\n"
|
|
|
+ "read 0 r12 r12 ; r12 = texNum value\n"
|
|
|
+ "multu r12 4096 r12 ; r12 = texture offset (64*64 per texture)\n"
|
|
|
|
|
|
- "load32 0xD00000 r1 ; r1 = framebuffer addr\n"
|
|
|
- "add r1 r7 r1 ; r1 = first pixel in line (fb+x)\n"
|
|
|
+ "addr2reg texture r11 ; r11 = texture array\n"
|
|
|
+ "add r12 r11 r12 ; r12 = texture[texNum]\n"
|
|
|
|
|
|
- "or r0 r1 r8 ; r8 = current pixel\n"
|
|
|
+ "load32 0x0082F0 r14 ; r14 = ceiling color\n"
|
|
|
|
|
|
- "multu r2 320 r9 ; r9 = drawStart VRAM offset\n"
|
|
|
- "add r9 r1 r9 ; r9 = last FB pos of before wall\n"
|
|
|
+ "addr2reg side r15 ; r15 = side addr\n"
|
|
|
+ "read 0 r15 r15 ; r15 = side value\n"
|
|
|
|
|
|
- "addr2reg texNum r12 ; r12 = texNum addr\n"
|
|
|
- "read 0 r12 r12 ; r12 = texNum value\n"
|
|
|
- "multu r12 4096 r12 ; r12 = texture offset (64*64 per texture)\n"
|
|
|
+ // draw until start
|
|
|
+ "RAYFX_drawVlineLoopCeiling:\n"
|
|
|
+ " write 0 r8 r14 ; write ceiling pixel\n"
|
|
|
+ " add r8 320 r8 ; go to next line pixel\n"
|
|
|
|
|
|
- "addr2reg texture r11 ; r11 = texture array\n"
|
|
|
- "add r12 r11 r12 ; r12 = texture[texNum]\n"
|
|
|
+ " bge r8 r9 2 ; keep looping until reached wall\n"
|
|
|
+ " jump RAYFX_drawVlineLoopCeiling\n"
|
|
|
|
|
|
- "load32 0x0082F0 r14 ; r14 = ceiling color\n"
|
|
|
|
|
|
- "addr2reg side r15 ; r15 = side addr\n"
|
|
|
- "read 0 r15 r15 ; r15 = side value\n"
|
|
|
|
|
|
- "; draw until start\n"
|
|
|
- "RAYFX_drawVlineLoopCeiling:\n"
|
|
|
- " write 0 r8 r14 ; write ceiling pixel\n"
|
|
|
- " add r8 320 r8 ; go to next line pixel\n"
|
|
|
|
|
|
- " bge r8 r9 2 ; keep looping until reached wall\n"
|
|
|
- " jump RAYFX_drawVlineLoopCeiling\n"
|
|
|
+ "multu r3 320 r9 ; r9 = drawEnd VRAM offset\n"
|
|
|
+ "add r9 r1 r9 ; r9 = last FB pos of wall\n"
|
|
|
|
|
|
+ "load32 8355711 r2 ; r2 = mask for darken color\n"
|
|
|
|
|
|
+ // draw until floor
|
|
|
+ "RAYFX_drawVlineLoopWall:\n"
|
|
|
+ " shiftrs r4 16 r11 ; r11 = texY = FPtoInt(texPos)\n"
|
|
|
+ " and r11 63 r11 ; r11 = r11 & (texHeight-1)\n"
|
|
|
+ " add r4 r5 r4 ; texPos += step\n"
|
|
|
|
|
|
+ " multu r11 64 r11 ; r11 = texHeight * texY \n"
|
|
|
+ " add r11 r6 r11 ; r11 += texX\n"
|
|
|
|
|
|
- "multu r3 320 r9 ; r9 = drawEnd VRAM offset\n"
|
|
|
- "add r9 r1 r9 ; r9 = last FB pos of wall\n"
|
|
|
+ " add r11 r12 r13 ; r13 = addr of color in texture array\n"
|
|
|
+ " read 0 r13 r13 ; r13 = pixel color\n"
|
|
|
|
|
|
- "load32 8355711 r2 ; r2 = mask for darken color\n"
|
|
|
+ " beq r15 r0 3 ; skip next two lines if not side of wall is hit\n"
|
|
|
+ " shiftrs r13 1 r13\n" // r13 >> 1
|
|
|
+ " and r13 r2 r13 ; r13 & darken color mask\n"
|
|
|
|
|
|
- "; draw until floor\n"
|
|
|
- "RAYFX_drawVlineLoopWall:\n"
|
|
|
- " shiftrs r4 16 r11 ; r11 = texY = FPtoInt(texPos)\n"
|
|
|
- " and r11 63 r11 ; r11 = r11 & (texHeight-1)\n"
|
|
|
- " add r4 r5 r4 ; texPos += step\n"
|
|
|
|
|
|
- " multu r11 64 r11 ; r11 = texHeight * texY \n"
|
|
|
- " add r11 r6 r11 ; r11 += texX\n"
|
|
|
+ " write 0 r8 r13 ; write texture pixel\n"
|
|
|
+ " add r8 320 r8 ; go to next line pixel\n"
|
|
|
|
|
|
- " add r11 r12 r13 ; r13 = addr of color in texture array\n"
|
|
|
- " read 0 r13 r13 ; r13 = pixel color\n"
|
|
|
+ " bge r8 r9 2 ; keep looping until reached floor\n"
|
|
|
+ " jump RAYFX_drawVlineLoopWall\n"
|
|
|
|
|
|
- " beq r15 r0 3 ; skip next two lines if not side of wall is hit\n"
|
|
|
- " shiftrs r13 1 r13 ; r13 >> 1\n"
|
|
|
- " and r13 r2 r13 ; r13 & darken color mask\n"
|
|
|
|
|
|
|
|
|
- " write 0 r8 r13 ; write texture pixel\n"
|
|
|
- " add r8 320 r8 ; go to next line pixel\n"
|
|
|
|
|
|
- " bge r8 r9 2 ; keep looping until reached floor\n"
|
|
|
- " jump RAYFX_drawVlineLoopWall\n"
|
|
|
+ "load32 239 r9 ; r9 = last y position\n"
|
|
|
+ "multu r9 320 r9 ; r9 = screen end VRAM offset\n"
|
|
|
+ "add r9 r1 r9 ; r9 = last FB pos of line\n"
|
|
|
|
|
|
+ "load32 0x9E9E9E r14 ; r14 = floor color\n"
|
|
|
|
|
|
+ "; draw until end of screen\n"
|
|
|
+ "RAYFX_drawVlineLoopFloor:\n"
|
|
|
+ " write 0 r8 r14 ; write floor pixel\n"
|
|
|
+ " add r8 320 r8 ; go to next line pixel\n"
|
|
|
|
|
|
+ " bgt r8 r9 2 ; keep looping until reached end of screen\n"
|
|
|
+ " jump RAYFX_drawVlineLoopFloor\n"
|
|
|
|
|
|
- "load 239 r9 ; r9 = last y position\n"
|
|
|
- "multu r9 320 r9 ; r9 = screen end VRAM offset\n"
|
|
|
- "add r9 r1 r9 ; r9 = last FB pos of line\n"
|
|
|
|
|
|
- "load32 0x9E9E9E r14 ; r14 = floor color\n"
|
|
|
+ "pop r15\n"
|
|
|
+ "pop r14\n"
|
|
|
+ "pop r13\n"
|
|
|
+ "pop r12\n"
|
|
|
+ "pop r11\n"
|
|
|
+ "pop r10\n"
|
|
|
+ "pop r9\n"
|
|
|
+ "pop r8\n"
|
|
|
+ "pop r7\n"
|
|
|
+ "pop r6\n"
|
|
|
+ "pop r5\n"
|
|
|
+ "pop r4\n"
|
|
|
+ "pop r3\n"
|
|
|
+ "pop r2\n"
|
|
|
+ "pop r1\n"
|
|
|
|
|
|
- "; draw until end of screen\n"
|
|
|
- "RAYFX_drawVlineLoopFloor:\n"
|
|
|
- " write 0 r8 r14 ; write floor pixel\n"
|
|
|
- " add r8 320 r8 ; go to next line pixel\n"
|
|
|
+ "RAYFX_skipRenderLine:\n"
|
|
|
+
|
|
|
|
|
|
- " bgt r8 r9 2 ; keep looping until reached end of screen\n"
|
|
|
- " jump RAYFX_drawVlineLoopFloor\n"
|
|
|
+ "add r1 1 r1\n" // r1 = x++
|
|
|
+ "load32 320 r15\n" // r15 = stop x loop (screenWidth)
|
|
|
+ "bge r1 r15 2\n" // keep looping until reached final vline (x) of screen
|
|
|
+ "jump RAYFX_screenXloop\n"
|
|
|
);
|
|
|
|
|
|
asm(
|
|
|
- "; restore registers\n"
|
|
|
+ // restore registers
|
|
|
"pop r15\n"
|
|
|
"pop r14\n"
|
|
|
"pop r13\n"
|
|
|
@@ -223,19 +542,6 @@ void RAYFX_drawTextureVertLine(fixed_point_t texPos, fixed_point_t step, word te
|
|
|
);
|
|
|
}
|
|
|
|
|
|
-// x and y start position
|
|
|
-fixed_point_t RAY_posX;
|
|
|
-fixed_point_t RAY_posY;
|
|
|
-
|
|
|
-// initial direction vector
|
|
|
-fixed_point_t RAY_dirX;
|
|
|
-fixed_point_t RAY_dirY;
|
|
|
-
|
|
|
-// the 2d raycaster version of camera plane
|
|
|
-fixed_point_t RAY_planeX;
|
|
|
-fixed_point_t RAY_planeY;
|
|
|
-
|
|
|
-word RAY_linex; // current vertical line being rendered (x of screen)
|
|
|
|
|
|
int main() {
|
|
|
// clear screen from text
|
|
|
@@ -261,143 +567,14 @@ int main() {
|
|
|
word rotationSpeed = 5; // degrees per frame
|
|
|
|
|
|
fixed_point_t moveSpeed = FP_StringToFP("0.15");
|
|
|
- fixed_point_t movePadding = FP_StringToFP("0.3");
|
|
|
+ fixed_point_t movePadding = 0;//FP_StringToFP("0.3");
|
|
|
|
|
|
word quitGame = 0;
|
|
|
|
|
|
while (!quitGame) {
|
|
|
|
|
|
- for (RAY_linex = 0; RAY_linex < screenWidth; RAY_linex++)
|
|
|
- {
|
|
|
- // calculate ray position and direction
|
|
|
- fixed_point_t cameraX =
|
|
|
- FP_Div(FP_intToFP(RAY_linex << 1), FP_intToFP(screenWidth)) -
|
|
|
- FP_intToFP(1); // x-coordinate in camera space
|
|
|
-
|
|
|
- fixed_point_t rayDirX = RAY_dirX + FP_Mult(RAY_planeX, cameraX);
|
|
|
- fixed_point_t rayDirY = RAY_dirY + FP_Mult(RAY_planeY, cameraX);
|
|
|
-
|
|
|
- // which box of the map we are in
|
|
|
- word mapX = FP_FPtoInt(RAY_posX);
|
|
|
- word mapY = FP_FPtoInt(RAY_posY);
|
|
|
-
|
|
|
- // length of ray from current position to next x or y-side
|
|
|
- fixed_point_t sideDistX;
|
|
|
- fixed_point_t sideDistY;
|
|
|
-
|
|
|
- // length of ray from one x or y-side to next x or y-side
|
|
|
- // these are derived as:
|
|
|
- // deltaDistX = sqrt(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX))
|
|
|
- // deltaDistY = sqrt(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY))
|
|
|
- // which can be simplified to abs(|rayDir| / rayDirX) and abs(|rayDir| /
|
|
|
- // rayDirY) where |rayDir| is the length of the vector (rayDirX, rayDirY).
|
|
|
- // Its length, unlike (RAY_dirX, RAY_dirY) is not 1, however this does not matter,
|
|
|
- // only the ratio between deltaDistX and deltaDistY matters, due to the
|
|
|
- // way the DDA stepping further below works. So the values can be computed
|
|
|
- // as below.
|
|
|
- // Division through zero is prevented by setting the result to a very
|
|
|
- // high value
|
|
|
- fixed_point_t deltaDistX =
|
|
|
- (rayDirX == 0) ? 1 << 30 : MATH_abs(FP_Div(FP_intToFP(1), rayDirX));
|
|
|
- fixed_point_t deltaDistY =
|
|
|
- (rayDirY == 0) ? 1 << 30 : MATH_abs(FP_Div(FP_intToFP(1), rayDirY));
|
|
|
-
|
|
|
- fixed_point_t perpWallDist;
|
|
|
-
|
|
|
- // what direction to step in x or y-direction (either +1 or -1)
|
|
|
- word stepX;
|
|
|
- word stepY;
|
|
|
-
|
|
|
- word hit = 0; // was there a wall hit?
|
|
|
-
|
|
|
- // calculate step and initial sideDist
|
|
|
- if (rayDirX < 0) {
|
|
|
- stepX = -1;
|
|
|
- sideDistX = FP_Mult((RAY_posX - FP_intToFP(mapX)), deltaDistX);
|
|
|
- } else {
|
|
|
- stepX = 1;
|
|
|
- sideDistX = FP_Mult((FP_intToFP(mapX + 1) - RAY_posX), deltaDistX);
|
|
|
- }
|
|
|
- if (rayDirY < 0) {
|
|
|
- stepY = -1;
|
|
|
- sideDistY = FP_Mult((RAY_posY - FP_intToFP(mapY)), deltaDistY);
|
|
|
- } else {
|
|
|
- stepY = 1;
|
|
|
- sideDistY = FP_Mult((FP_intToFP(mapY + 1) - RAY_posY), deltaDistY);
|
|
|
- }
|
|
|
-
|
|
|
- // perform DDA
|
|
|
- while (hit == 0) {
|
|
|
- // jump to next map square, either in x-direction, or in y-direction
|
|
|
- if (sideDistX < sideDistY) {
|
|
|
- sideDistX += deltaDistX;
|
|
|
- mapX += stepX;
|
|
|
- side = 0;
|
|
|
- } else {
|
|
|
- sideDistY += deltaDistY;
|
|
|
- mapY += stepY;
|
|
|
- side = 1;
|
|
|
- }
|
|
|
- // Check if ray has hit a wall
|
|
|
- if (worldMap[mapX][mapY] > 0) hit = 1;
|
|
|
- }
|
|
|
-
|
|
|
- // Calculate distance projected on camera direction. This is the shortest
|
|
|
- // distance from the point where the wall is hit to the camera plane.
|
|
|
- // Euclidean to center camera point would give fisheye effect! This can be
|
|
|
- // computed as (mapX - RAY_posX + (1 - stepX) / 2) / rayDirX for side == 0, or
|
|
|
- // same formula with Y for size == 1, but can be simplified to the code
|
|
|
- // below thanks to how sideDist and deltaDist are computed: because they
|
|
|
- // were left scaled to |rayDir|. sideDist is the entire length of the ray
|
|
|
- // above after the multiple steps, but we subtract deltaDist once because
|
|
|
- // one step more into the wall was taken above.
|
|
|
- if (side == 0)
|
|
|
- perpWallDist = (sideDistX - deltaDistX);
|
|
|
- else
|
|
|
- perpWallDist = (sideDistY - deltaDistY);
|
|
|
-
|
|
|
- // Calculate height of line to draw on screen
|
|
|
- word lineHeight =
|
|
|
- FP_FPtoInt(FP_Div(FP_intToFP(screenHeight), perpWallDist));
|
|
|
-
|
|
|
- // calculate lowest and highest pixel to fill in current stripe
|
|
|
- drawStart = -(lineHeight >> 1) + (screenHeight >> 1);
|
|
|
- if (drawStart < 0) drawStart = 0;
|
|
|
- drawEnd = (lineHeight >> 1) + (screenHeight >> 1);
|
|
|
- if (drawEnd >= screenHeight) drawEnd = screenHeight - 1;
|
|
|
-
|
|
|
- // texturing calculations
|
|
|
- texNum = worldMap[mapX][mapY] -
|
|
|
- 1; // 1 subtracted from it so that texture 0 can be used!
|
|
|
-
|
|
|
- // calculate value of wallX
|
|
|
- fixed_point_t wallX; // where exactly the wall was hit
|
|
|
- if (side == 0)
|
|
|
- wallX = RAY_posY + FP_Mult(perpWallDist, rayDirY);
|
|
|
- else
|
|
|
- wallX = RAY_posX + FP_Mult(perpWallDist, rayDirX);
|
|
|
- word floormask = 0xFFFF;
|
|
|
- wallX &= floormask; // wallX-=floor(wallX)
|
|
|
-
|
|
|
- // x coordinate on the texture
|
|
|
- word texX = FP_FPtoInt(FP_Mult(wallX, FP_intToFP(texWidth)));
|
|
|
- if (side == 0 && rayDirX > 0) texX = texWidth - texX - 1;
|
|
|
- if (side == 1 && rayDirY < 0) texX = texWidth - texX - 1;
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|
-
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|
- // How much to increase the texture coordinate per screen pixel
|
|
|
- fixed_point_t step =
|
|
|
- FP_Div(FP_intToFP(texHeight), FP_intToFP(lineHeight));
|
|
|
- // Starting texture coordinate
|
|
|
- fixed_point_t texPos = FP_Mult(
|
|
|
- FP_intToFP(drawStart - (screenHeight >> 1) + (lineHeight >> 1)),
|
|
|
- step);
|
|
|
-
|
|
|
- // TMP fix for first line not rendering correctly and prevent crash when
|
|
|
- // start > screen end
|
|
|
- if (RAY_linex > 0 && drawStart < screenHeight) {
|
|
|
- RAYFX_drawTextureVertLine(texPos, step, texX, RAY_linex);
|
|
|
- }
|
|
|
- }
|
|
|
+ // render screen
|
|
|
+ RAYFX_renderScreen();
|
|
|
|
|
|
// check which button is held
|
|
|
if (BDOS_USBkeyHeld(BTN_LEFT)) {
|
bart