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Merge pull request #536 from MonstersGoBoom/master

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Textri using constant slope and fixed point math
This commit is contained in:
Vadim Grigoruk
2018-02-20 22:16:17 +03:00
committed by GitHub
parent ea8c269b57 847d848c88
commit c13516125d
1 changed files with 32 additions and 19 deletions
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51
src/tic.c
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@@ -27,6 +27,7 @@
#include <math.h> #include <math.h>
#include <ctype.h> #include <ctype.h>
#include <stddef.h> #include <stddef.h>
#include <stddef.h>
#include "ticapi.h" #include "ticapi.h"
#include "tools.h" #include "tools.h"
@@ -823,10 +824,8 @@ static struct
{ {
s16 Left[TIC80_HEIGHT]; s16 Left[TIC80_HEIGHT];
s16 Right[TIC80_HEIGHT]; s16 Right[TIC80_HEIGHT];
float ULeft[TIC80_HEIGHT]; s32 ULeft[TIC80_HEIGHT];
float VLeft[TIC80_HEIGHT]; s32 VLeft[TIC80_HEIGHT];
float URight[TIC80_HEIGHT];
float VRight[TIC80_HEIGHT];
} SidesBuffer; } SidesBuffer;
static void initSidesBuffer() static void initSidesBuffer()
@@ -852,14 +851,12 @@ static void setSideTexPixel(s32 x, s32 y, float u, float v)
if (x < SidesBuffer.Left[yy]) if (x < SidesBuffer.Left[yy])
{ {
SidesBuffer.Left[yy] = x; SidesBuffer.Left[yy] = x;
SidesBuffer.ULeft[yy] = u; SidesBuffer.ULeft[yy] = u*65536.0f;
SidesBuffer.VLeft[yy] = v; SidesBuffer.VLeft[yy] = v*65536.0f;
} }
if (x > SidesBuffer.Right[yy]) if (x > SidesBuffer.Right[yy])
{ {
SidesBuffer.Right[yy] = x; SidesBuffer.Right[yy] = x;
SidesBuffer.URight[yy] = u;
SidesBuffer.VRight[yy] = v;
} }
} }
} }
@@ -1015,22 +1012,37 @@ static void api_textri(tic_mem* memory, float x1, float y1, float x2, float y2,
V0.x = (float)x1; V0.y = (float)y1; V0.u = (float)u1; V0.v = (float)v1; V0.x = (float)x1; V0.y = (float)y1; V0.u = (float)u1; V0.v = (float)v1;
V1.x = (float)x2; V1.y = (float)y2; V1.u = (float)u2; V1.v = (float)v2; V1.x = (float)x2; V1.y = (float)y2; V1.u = (float)u2; V1.v = (float)v2;
V2.x = (float)x3; V2.y = (float)y3; V2.u = (float)u3; V2.v = (float)v3; V2.x = (float)x3; V2.y = (float)y3; V2.u = (float)u3; V2.v = (float)v3;
// calculate the slope of the surface
// use floats here
double denom = (V0.x - V2.x) * (V1.y - V2.y) - (V1.x - V2.x) * (V0.y - V2.y);
if (denom == 0.0)
{
return;
}
double id = 1.0 / denom;
float dudx, dvdx;
// this is the UV slope across the surface
dudx = ((V0.u - V2.u) * (V1.y - V2.y) - (V1.u - V2.u) * (V0.y - V2.y)) * id;
dvdx = ((V0.v - V2.v) * (V1.y - V2.y) - (V1.v - V2.v) * (V0.y - V2.y)) * id;
// convert to fixed
s32 dudxs = dudx * 65536.0f;
s32 dvdxs = dvdx * 65536.0f;
initSidesBuffer(); initSidesBuffer();
ticTexLine(memory, &V0, &V1); ticTexLine(memory, &V0, &V1);
ticTexLine(memory, &V1, &V2); ticTexLine(memory, &V1, &V2);
ticTexLine(memory, &V2, &V0); ticTexLine(memory, &V2, &V0);
{ {
for (s32 y = 0; y < TIC80_HEIGHT; y++) for (s32 y = 0; y < TIC80_HEIGHT; y++)
{ {
float width = SidesBuffer.Right[y] - SidesBuffer.Left[y]; float width = SidesBuffer.Right[y] - SidesBuffer.Left[y];
if (width > 0) if (width > 0)
{ {
float du = (SidesBuffer.URight[y] - SidesBuffer.ULeft[y]) / width; s32 u = SidesBuffer.ULeft[y];
float dv = (SidesBuffer.VRight[y] - SidesBuffer.VLeft[y]) / width; s32 v = SidesBuffer.VLeft[y];
float u = SidesBuffer.ULeft[y];
float v = SidesBuffer.VLeft[y];
for (s32 x = (s32)SidesBuffer.Left[y]; x <= (s32)SidesBuffer.Right[y]; ++x) for (s32 x = (s32)SidesBuffer.Left[y]; x <= (s32)SidesBuffer.Right[y]; ++x)
{ {
@@ -1040,8 +1052,8 @@ static void api_textri(tic_mem* memory, float x1, float y1, float x2, float y2,
{ {
enum {MapWidth = TIC_MAP_WIDTH * TIC_SPRITESIZE, MapHeight = TIC_MAP_HEIGHT * TIC_SPRITESIZE}; enum {MapWidth = TIC_MAP_WIDTH * TIC_SPRITESIZE, MapHeight = TIC_MAP_HEIGHT * TIC_SPRITESIZE};
s32 iu = (s32)u % MapWidth; s32 iu = (u >> 16) % MapWidth;
s32 iv = (s32)v % MapHeight; s32 iv = (v >> 16) % MapHeight;
while (iu < 0) iu += MapWidth; while (iu < 0) iu += MapWidth;
while (iv < 0) iv += MapHeight; while (iv < 0) iv += MapHeight;
@@ -1056,16 +1068,16 @@ static void api_textri(tic_mem* memory, float x1, float y1, float x2, float y2,
{ {
enum{SheetWidth = TIC_SPRITESHEET_SIZE, SheetHeight = TIC_SPRITESHEET_SIZE * TIC_SPRITE_BANKS}; enum{SheetWidth = TIC_SPRITESHEET_SIZE, SheetHeight = TIC_SPRITESHEET_SIZE * TIC_SPRITE_BANKS};
s32 iu = (s32)(u) & (SheetWidth - 1); s32 iu = (u>>16) & (SheetWidth - 1);
s32 iv = (s32)(v) & (SheetHeight - 1); s32 iv = (v>>16) & (SheetHeight - 1);
const u8 *buffer = &ptr[((iu >> 3) + ((iv >> 3) << 4)) << 5]; const u8 *buffer = &ptr[((iu >> 3) + ((iv >> 3) << 4)) << 5];
u8 color = tic_tool_peek4(buffer, (iu & 7) + ((iv & 7) << 3)); u8 color = tic_tool_peek4(buffer, (iu & 7) + ((iv & 7) << 3));
if (color != chroma) if (color != chroma)
setPixel(machine, x, y, color); setPixel(machine, x, y, color);
} }
} }
u += du; u += dudxs;
v += dv; v += dvdxs;
} }
} }
} }
@@ -1073,6 +1085,7 @@ static void api_textri(tic_mem* memory, float x1, float y1, float x2, float y2,
} }
static void api_sprite(tic_mem* memory, const tic_tiles* src, s32 index, s32 x, s32 y, u8* colors, s32 count) static void api_sprite(tic_mem* memory, const tic_tiles* src, s32 index, s32 x, s32 y, u8* colors, s32 count)
{ {
drawSprite(memory, src, index, x, y, colors, count, 1, tic_no_flip, tic_no_rotate); drawSprite(memory, src, index, x, y, colors, count, 1, tic_no_flip, tic_no_rotate);