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C/C++ Source or Header | 1992-04-23 | 21.3 KB | 628 lines | [TEXT/KAHL]

/*------------------------------------------------------------------------------ # # Program: Tutor3D™ # # Copyright ©1991 Lincoln Lydick # All Rights Reserved. # # NOTES ----- Include the following libraries: MacTraps SANE The initialization is in C, we use C declarations, and the event loop is in assembly. For an overall explanation of what's happening at each routine, see the THINK C code. -----------------------------------------------------------*/ #include "SANE.h" /* for initialization only. */ #define kCenterH 256 /* this is origin.h */ #define kCenterV 171 /* this is origin.v */ #define kMaxObjects 6 /* max num objects we draw */ #define kAngleResolution 12 /* minutes per deqree (never 0) */ #define kProjDistance 450 /* distance to projection plane */ #define kLineToTrapNum 0xA891 /* trap num for _LineTo */ #define kNotBWAlertNum 256 /* ALRT id for monitor bit depth > 1 */ enum ObjectType {cube, pyramid}; /* we define two types of objects */ typedef struct {short x, y, z; } Point3D; /* structure for a 3 dimensional pt. */ typedef struct { Point3D pt3D; short angle, sine, cosine; } ViewerInfo; /* structure for viewer's position. */ typedef struct { enum ObjectType objType; Point3D pt3D; short angle, halfWidth, height; Boolean rotates, moves; } ObjectInfo; /* structure for an object. */ typedef short TrigTable[1]; TrigTable *gTrigTable; ViewerInfo gViewer; ObjectInfo gObject[kMaxObjects]; BitMap gBitMap; GrafPort gAnimationPort; Rect gVisRect; Point gVertex[8]; Point3D gDelta; Ptr gLineToAddress; short gDiffRows; /************************************************************/ /* /* Assign parameters to an object (a cube or pyramid). /* /************************************************************/ static void NewObject(short index, enum ObjectType theType, short width, short height, Boolean rotates, Boolean moves, short x, short y, short z) { register ObjectInfo *obj; obj = &gObject[index]; obj->objType = theType; obj->halfWidth = width/2; obj->height = height; obj->rotates = rotates; obj->moves = moves; obj->angle = 0; obj->pt3D.x = x; obj->pt3D.y = y; obj->pt3D.z = z; } /************************************************************/ /* /* Initialize of all our globals, build the trig table, set up an offscreen buffer, create a new /* window, and initialize all the objects to be drawn. /* /************************************************************/ static void Initialize(void) { WindowPtr gWindow; extended angle; short i; InitGraf(&thePort); InitFonts(); InitWindows(); InitMenus(); TEInit(); InitDialogs(0L); InitCursor(); FlushEvents(everyEvent, 0); SetCursor(*GetCursor(crossCursor)); if ((*(*GetMainDevice())->gdPMap)->pixelSize > 1) { InitCursor(); StopAlert(kNotBWAlertNum, NULL); /* tell user to switch to B&W.*/ ExitToShell(); } gLineToAddress = (Ptr) NGetTrapAddress(kLineToTrapNum, ToolTrap); gLineToAddress = StripAddress(gLineToAddress); gTrigTable = (TrigTable*)NewPtr(((90*kAngleResolution)+1)*2); for (i = 0, angle = 0.00; i <= 90*kAngleResolution; i++, angle += 0.017453292/kAngleResolution) *gTrigTable[i] = sin(angle)*1000; /* save the value (x1000) in an array.*/ /* give the viewer an initial direction and position…*/ gViewer.angle = gViewer.sine = gViewer.pt3D.x = gViewer.pt3D.y = 0; gViewer.pt3D.z = 100; gViewer.cosine = 999; NewObject(0, cube, 120, 120, false, false, -150, 600, 0); /* create some objects…*/ NewObject(1, cube, 300, 300, true, false, -40, 1100, 60); NewObject(2, cube, 40, 10, true, true, 0, 500, 0); NewObject(3, pyramid, 160, 160, false, false, 200, 700, 0); NewObject(4, pyramid, 80, -80, true, false, 200, 700, 240); NewObject(5, pyramid, 60, 60, false, false, -40, 1100, 0); SetRect(&gVisRect, -100, -100, 512+100, 342+100); /* visible bounds for objects.*/ SetRect(&gBitMap.bounds, 0, 0, 512, 342); gBitMap.rowBytes = ((512+15)/16)*2; gBitMap.baseAddr = NewPtr(342*(((512+15)/16)*2)); /* allocate bit map*/ gWindow = NewWindow(0L, &gBitMap.bounds, "\p", true, 2, (Ptr)-1, false, 0); gDiffRows = gWindow->portBits.rowBytes - gBitMap.rowBytes; OpenPort(&gAnimationPort); /* we draw to an offscreen buffer.*/ SetPort(&gAnimationPort); SetPortBits(&gBitMap); PenPat(white); } /************************************************************/ /* /* Here's the assembly. VERY IMPORTANT!! Several low memory globals are used /* and could cause serious problems on different or future macs. Also, a couple of /* numbers are "hard coded" and rely on others - not allowing for much flexibility. /* This is, however, not an example of how to program the 680x0 or proper ROM /* useage, but does show some ways to speed things up. /* /************************************************************/ void main(void) { asm { ;------Start------ ; The Main Event (loop). Cycle until the mouse button is pressed. jsr Initialize ; set up params… mainloop: jsr @_FillPortBlack ; fill the bitmap with black jsr @_CheckViewer ; get scoop on viewer jsr @_DrawObjects ; our drawing pipeline jsr @_DrawCrossHair ; simple crosshair jsr @_BitBlit ; copy it to the screen tst.b 0x172 ; MBState=$172, hardware mouse button state [byte] I-279 bmi @mainloop ; if not, loop. moveq #0x0000000A, d0 ; mDownMask+keyDownMask, 0 _FlushEvents ; flush em out of the queue _ExitToShell ; bye… ;------DrawCrossHair------ ; Draw a crosshair at the center of the window. ; @_DrawCrossHair: move.l #0x00A10100, gAnimationPort.pnLoc ; ie., MoveTo(256, 161) move.l #0x00140000, -(SP) ; ie., 0, 20 _Line move.l #0x00AB00F6, gAnimationPort.pnLoc ; 246, 171 move.l #0x00000014, -(SP) ; 20, 0 _Line rts ;------FillPortBlack------ ; Replacement for FillRect(). Simply fills the bitmap ; with 0xFFFFFFFF (black) by moving 44 bytes per loop. ; Note: this map (512*342) can't be filled evenly so we ; tack on a little at the end. @_FillPortBlack: lea @elevenBlacks, a0 movem.l (a0), d1-d7/a1-a4 move.w #496, d0 ; 496 = (((length * width) / 32 bits) / 11 longs at a time)-1 movea.l gBitMap.baseAddr, a0 ; ptr to the bitmap's data fillLoop: movem.l d1-d7/a1-a4, (a0) ; a fast fill… adda.l #44, a0 ; moved 44 bytes (11 * 4) dbra d0, @fillLoop ; loop movem.l d1-d5, (a0) ; last little bit cause bitmap's not an even MOD 44 rts ;------BitBlit------ ; Replacement for CopyBits(). Calculate the src and dst bitmap ; address, and the difference in rowbytes. The difference will ; be the amount to add to the dst bitmap (the screen) to move ; down a vertical row. We move 16 longs per horizontal ; scan line (16 * 32bits = 512) and 342 rows (height of map). ; ; This runs over 33% faster than CopyBits() since we know ; exactly what to "move" and how to calculate it. HOWEVER, it ; is a dangerous practice to copy directly to the screen and ; further tests should be performed for any serious application. @_BitBlit: _HideCursor ; don't want to interfere w/ cursor image movea.l gBitMap.baseAddr, a0 ; source bitmap ptr movea.l 0x824, a1 ; ScrnBase=$824, Screen base [pointer] I-473 move.w #342-1, d0 ; 342 rows to transfer move.w gDiffRows, d1 nextline: move.l (a0)+, (a1)+ ; first 32 bits of the 512 move.l (a0)+, (a1)+ ; second, and so on… move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ move.l (a0)+, (a1)+ adda.w d1, a1 ; move source down a row dbra d0, @nextline ; loop _ShowCursor ; bring it back rts ;------MyPtInRect------ ; Replacement for _PtInRect. ; ->a0 = Rect *r ; ->d0 = Point pt, @_MyPtInRect: moveq #0, d1 cmp.w OFFSET(Rect, left)(a0), d0 ; compare (left, h) blt @ptNRect cmp.w OFFSET(Rect, right)(a0), d0 ; compare (right, h) bgt @ptNRect swap d0 ; try the vertical. cmp.w OFFSET(Rect, top)(a0), d0 ; compare (top, v) blt @ptNRect cmp.w OFFSET(Rect, bottom)(a0), d0 ; compare (bottom, v) bgt @ptNRect moveq #1, d1 ptNRect: tst.b d1 ; set CCR for caller. rts ;------GetTrigValues------ ; Determine the sine and cosine values for an angle using our trig table. ; <->a0 = *angle ; <->a1 = *sine ; <->a2 = *cosine ; uses a3, d0, d1 @_GetTrigValues: cmpi.w #360*kAngleResolution, (a0) ; angle >= 360 degrees? blt @trig1 ; nope, branch addi.w #-360*kAngleResolution, (a0) ; subtract 360 degrees. bra @trig2 trig1: tst.w (a0) ; angle < 0? bge @trig2 ; nope, branch addi.w #360*kAngleResolution, (a0) ; add 360 degrees to angle trig2: move.w (a0), d0 ; angle into d0 movea.l gTrigTable, a3 ; trig table ptr into a3 cmpi.w #90*kAngleResolution, d0 ; angle <= 90? bgt @trig180 ; nope, branch add.w d0, d0 ; address of value is 2*angle move.w (a3, d0.w), (a1) ; ie., new sine = gTrigTable[angle] move.w #180*kAngleResolution, d1 ; 90 * 2 = 180 sub.w d0, d1 ; get inverse move.w (a3, d1.w), (a2) ; ie., new cosine = gTrigTable[90-angle] rts trig180: cmpi.w #180*kAngleResolution, d0 ; angle <= 180 degrees? bgt @trig270 ; nope, branch move.w #180*kAngleResolution, d1 ; sub.w d0, d1 add.w d1, d1 move.w (a3, d1.w), (a1) ; ie., new sine = gTrigTable[180-angle] addi.w #-90*kAngleResolution, d0 add.w d0, d0 move.w (a3, d0.w), (a2) ; ie., new cosine = -gTrigTable[angle-90] neg.w (a2) rts trig270: cmpi.w #270*kAngleResolution, d0 ; angle <= 270? bgt @trig360 addi.w #-180*kAngleResolution, d0 add.w d0, d0 move.w (a3, d0.w), (a1) ; ie., new sine = -gTrigTable[angle-180] neg.w (a1) move.w #270*kAngleResolution, d0 sub.w (a0), d0 add.w d0, d0 move.w (a3, d0.w), (a2) ; ie., new cosine = -gTrigTable[270-angle] neg.w (a2) rts trig360: move.w #360*kAngleResolution, d1 sub.w d0, d1 add.w d1, d1 move.w (a3, d1.w), (a1) ; ie., new sine = -gTrigTable[360-angle] neg.w (a1) addi.w #-270*kAngleResolution, d0 add.w d0, d0 move.w (a3, d0.w), (a2) ; ie., new cosine = gTrigTable[angle-270] rts ;------CheckViewer------ ; See if the viewer has moved by checking the mouse and keyboard. ; If moved the mouse, slice up the mouse into a velocity and angle factor, then ; grab the new sine and cosine values. Finally, find the new position ; in the x, y plane and if the 'q' or 'w' key is down, change the z position ; as well. @_CheckViewer: move.l 0x830, d0 ; Mouse=$830; processed mouse location [long] I-36 lea @mouse, a3 ; temp holding move.l d0, (a3) ; save mouse position lea gBitMap.bounds, a0 bsr @_MyPtInRect ; see if mouse is in window beq @endView; ; nope, branch addi.w #-kCenterH, OFFSET(Point, h)(a3) ; get difference addi.w #-kCenterV, OFFSET(Point, v)(a3) move.w OFFSET(Point, h)(a3), d0 ; get horizontal ext.l d0 ; clear upper 16 bits for divide divs #10, d0 ; slice it up add.w d0, gViewer.angle ; add to old angle move.w OFFSET(Point, v)(a3), d0 ; get vertical ext.l d0 ; clear upper 16 bits for divide divs #5, d0 ; slice it up neg.w d0 ; need to negate move.w d0, d7 ; save velocity in d7 lea gViewer.angle, a0 ; set up to call routine lea gViewer.sine, a1 lea gViewer.cosine, a2 bsr @_GetTrigValues ; get the new sine/cosine move.w gViewer.sine, d0 ; the sine into d0 muls d7, d0 ; mult by velocity divs #1000, d0 ; always divide by 1000 add.w d0, gViewer.pt3D.x ; add to old x position move.w gViewer.cosine, d0 ; the cosine into d0 muls d7, d0 ; mult by velocity divs #1000, d0 ; always divide by 1000 add.w d0, gViewer.pt3D.y ; add to old y position move.l 0x174, d0 ; KeyMap=$174; keyboard bitmap (by code #) [2 longs] I-251 btst #20, d0 ; 'q' key beq @testDn ; is it down? addq.w #3, gViewer.pt3D.z ; add some altitude to the z testDn: btst #21, d0 ; 'w' key beq @endView ; is it down? addi.w #-3, gViewer.pt3D.z ; subtract some altitude to the z endView: rts ;------Point2Screen------ ; Rotate a point around the z axis and find it's location in 2D space. ; <->a0 = Point *pt ; uses d0, d1, d2 @_Point2Screen: move.w gViewer.cosine, d0 ; [EQ.6] muls OFFSET(Point, h)(a0), d0 ; pt.h * cosine divs #1000, d0 ; divide by 1000 move.w gViewer.sine, d1 muls OFFSET(Point, v)(a0), d1 ; pt.v * sine divs #1000, d1 ; divide by 1000 sub.w d1, d0 ; subtract the two, yielding the new horizontal move.w gViewer.sine, d1 ; [EQ.7] muls OFFSET(Point, h)(a0), d1 ; pt.h * sine divs #1000, d1 ; divide by 1000 move.w gViewer.cosine, d2 muls OFFSET(Point, v)(a0), d2 ; pt.v * cosine divs #1000, d2 ; divide by 1000 add.w d2, d1 ; add the two, yielding the new vertical bgt @project ; if (vertical <= 0) then vertical = 1 moveq #1, d1 project: muls #kProjDistance, d0 ; [EQ.8]. new horizontal * kProjDistance divs d1, d0 ; divide by the vertical addi.w #kCenterH, d0 ; add origin.h (center of window) move.w d0, OFFSET(Point, h)(a0) ; save the new horizontal position move.w #kProjDistance, d0 ; [EQ.9] muls gDelta.z, d0 ; height * kProjDistance divs d1, d0 ; divide by the vertical addi.w #kCenterV, d0 ; add origin.v (center of window) move.w d0, OFFSET(Point, v)(a0) ; save the new vertical position rts ;------RotateObject------ ; Rotate an object around the z axis and translate it to the ; correct position based on delta. ; ->a4 = ObjectInfo *object ; uses a0, a1, a2, a6, d0, d1, d2 @_RotateObject: link a6, #-8 ; tempPt = -2(a6), sine = -6(a6), cosine = -8(a6) moveq #-6*kAngleResolution, d0 ; pyraminds rotate by -6 cmpi.b #1, OFFSET(ObjectInfo, objType)(a4) ; is it a pyramid? beq @addAngle ; nope, branch moveq #2*kAngleResolution, d0 ; cubes rotate by 2 addAngle: add.w d0, OFFSET(ObjectInfo, angle)(a4) ; add to old angle lea OFFSET(ObjectInfo, angle)(a4), a0 ; the angle lea -6(a6), a1 ; the sine lea -8(a6), a2 ; the cosine bsr @_GetTrigValues ; get the sine and cosine of angle tst.b OFFSET(ObjectInfo, moves)(a4) ; does object move? beq @rotate ; nope, branch move.w -6(a6), d0 ; sine into d0 muls #20, d0 ; velocity = 20 divs #1000, d0 ; divide by 1000 add.w d0, OFFSET(ObjectInfo, pt3D.x)(a4); update new position x move.w -8(a6), d0 ; cosine into d0 muls #-20, d0 ; velocity divs #1000, d0 ; divide by 1000 add.w d0, OFFSET(ObjectInfo, pt3D.y)(a4) ; update new y rotate: moveq #3, d2 ; loop counter (vertices 0 to 3) lea gVertex, a0 ; our array of points rtLoop: move.l (a0), -4(a6) ; tempPt = gVertex[i]; move.w -6(a6), d0 ; (sine) compute new vertical muls -2(a6), d0 ; tempPt.h*sine divs #1000, d0 ; divide by 1000 move.w -8(a6), d1 ; cosine muls -4(a6), d1 ; tempPt.v*cosine divs #1000, d1 ; divide by 1000 add.w d1, d0 ; add em up add.w gDelta.y, d0 ; now translate from origin move.w d0, (a0)+ ; new v position in space move.w -8(a6), d0 ; (cosine) compute new horizontal muls -2(a6), d0 ; tempPt.h divs #1000, d0 ; divide by 1000 move.w -6(a6), d1 ; sine muls -4(a6), d1 ; tempPt.v*sine divs #1000, d1 ; divide by 1000 sub.w d1, d0 ; subtract the two add.w gDelta.x, d0 ; now translate from origin move.w d0, (a0)+ ; new h position in space dbra d2, @rtLoop ; loop unlk a6 ; kill stackframe rts ;------DrawObjects------ ; For all of our cubes and pyramids, index thru each ; and calculate sizes, translate, rotate, check for visibility, ; and finally draw them. ; uses a0, a3, a4, d0, d1, d3, & d7 <- (loop counter) @_DrawObjects clr.w d7 ; d7 is our loop counter objloop: move.w d7, d0 ; start to compute address of object asl.w #4, d0 ; multiply by 16 (size of record) lea gObject, a4 ; our array adda.w d0, a4 ; address of object move.w OFFSET(ObjectInfo, pt3D.x)(a4), d0 ; [EQ.3] sub.w gViewer.pt3D.x, d0 ; pt.x - viewer.x move.w d0, gDelta.x ; save in delta.x move.w OFFSET(ObjectInfo, pt3D.y)(a4), d0 ; [EQ.4] sub.w gViewer.pt3D.y, d0 ; pt.y - viewer.y move.w d0, gDelta.y ; save in delta.y move.w gViewer.pt3D.z, d0 ; [EQ.5] sub.w OFFSET(ObjectInfo, pt3D.z)(a4), d0 move.w d0, gDelta.z ; save in delta.z tst.b OFFSET(ObjectInfo, rotates)(a4) ; do we rotate this one? beq @staticObj ; nope, branch move.w OFFSET(ObjectInfo, halfWidth)(a4), d0 move.w d0, gVertex[1].h move.w d0, gVertex[2].h move.w d0, gVertex[2].v move.w d0, gVertex[3].v neg.w d0 move.w d0, gVertex[0].h move.w d0, gVertex[0].v move.w d0, gVertex[1].v move.w d0, gVertex[3].h bsr @_RotateObject ; go rotate object at origin bra @chkType staticObj: move.w OFFSET(ObjectInfo, halfWidth)(a4), d0 neg.w d0 move.w d0, d1 add.w gDelta.x, d0 add.w gDelta.y, d1 move.w d0, gVertex[0].h move.w d0, gVertex[3].h move.w d1, gVertex[0].v move.w d1, gVertex[1].v move.w OFFSET(ObjectInfo, halfWidth)(a4), d0 move.w d0, d1 add.w gDelta.x, d0 add.w gDelta.y, d1 move.w d0, gVertex[1].h move.w d0, gVertex[2].h move.w d1, gVertex[2].v move.w d1, gVertex[3].v chkType: tst.b OFFSET(ObjectInfo, objType)(a4) ; what kind, cube or pyramid? beq @cube ; not a pyramid, branch move.w gDelta.x, gVertex[4].h ; assine the apex of the pyramid move.w gDelta.y, gVertex[4].v ; ditto bra @plotZero ; branch cube: move.l gVertex[0], gVertex[4] ; assign top plane of cube move.l gVertex[1], gVertex[5] move.l gVertex[2], gVertex[6] move.l gVertex[3], gVertex[7] plotZero: lea gVertex[0], a0 ; get vertex 0 first bsr @_Point2Screen ; rotate and plot on window. move.l gVertex[0], d0 ; get point lea gVisRect, a0 ; our visable rect bsr @_MyPtInRect ; check pt in rect… beq @next ; not visable, branch lea gVertex[1], a0 ; rotate and plot on window. bsr @_Point2Screen lea gVertex[2], a0 ; rotate and plot on window. bsr @_Point2Screen lea gVertex[3], a0 ; rotate and plot on window. bsr @_Point2Screen move.w gDelta.z, d0 sub.w OFFSET(ObjectInfo, height)(a4), d0 move.w d0, gDelta.z lea gVertex[4], a0 ; rotate and plot on window. bsr @_Point2Screen movea.l gLineToAddress, a3 move.l gVertex[0], gAnimationPort.pnLoc ; connect the dots… move.l gVertex[1], -(sp) jsr (a3) move.l gVertex[2], -(sp) jsr (a3) move.l gVertex[3], -(sp) jsr (a3) move.l gVertex[0], -(sp) jsr (a3) move.l gVertex[4], -(sp) jsr (a3) tst.b OFFSET(ObjectInfo, objType)(a4) beq @drawcube ; not a pyramid, branch move.l gVertex[1], -(sp) jsr (a3) move.l gVertex[2], gAnimationPort.pnLoc move.l gVertex[4], -(sp) jsr (a3) move.l gVertex[3], -(sp) jsr (a3) bra @next drawcube: lea gVertex[5], a0 ; rotate and plot on window. bsr @_Point2Screen lea gVertex[6], a0 ; rotate and plot on window. bsr @_Point2Screen lea gVertex[7], a0 ; rotate and plot on window. bsr @_Point2Screen movea.l gLineToAddress, a3 move.l gVertex[5], -(sp) jsr (a3) move.l gVertex[6], -(sp) jsr (a3) move.l gVertex[7], -(sp) jsr (a3) move.l gVertex[4], -(sp) jsr (a3) move.l gVertex[1], gAnimationPort.pnLoc move.l gVertex[5], -(sp) jsr (a3) move.l gVertex[2], gAnimationPort.pnLoc move.l gVertex[6], -(sp) jsr (a3) move.l gVertex[3], gAnimationPort.pnLoc move.l gVertex[7], -(sp) jsr (a3) next: addi.w #1, d7 ; increment counter cmpi.w #kMaxObjects, d7 ; last object? blt @objloop ; loop rts /********************************************************************/ @mouse dc.l 0 @elevenBlacks dc.l -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } }