ppsspp/GPU/Software/Clipper.cpp

331 lines
11 KiB
C++

// Copyright (c) 2013- PPSSPP Project.
// This program 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, version 2.0 or later versions.
// This program 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 2.0 for more details.
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
#include <algorithm>
#include "GPU/GPUState.h"
#include "GPU/Software/Clipper.h"
#include "GPU/Software/Rasterizer.h"
#include "profiler/profiler.h"
namespace Clipper {
enum {
SKIP_FLAG = -1,
CLIP_POS_X_BIT = 0x01,
CLIP_NEG_X_BIT = 0x02,
CLIP_POS_Y_BIT = 0x04,
CLIP_NEG_Y_BIT = 0x08,
CLIP_POS_Z_BIT = 0x10,
CLIP_NEG_Z_BIT = 0x20,
};
static inline int CalcClipMask(const ClipCoords& v)
{
int mask = 0;
if (v.x > v.w) mask |= CLIP_POS_X_BIT;
if (v.x < -v.w) mask |= CLIP_NEG_X_BIT;
if (v.y > v.w) mask |= CLIP_POS_Y_BIT;
if (v.y < -v.w) mask |= CLIP_NEG_Y_BIT;
if (v.z > v.w) mask |= CLIP_POS_Z_BIT;
if (v.z < -v.w) mask |= CLIP_NEG_Z_BIT;
return mask;
}
#define AddInterpolatedVertex(t, out, in, numVertices) \
{ \
Vertices[numVertices]->Lerp(t, *Vertices[out], *Vertices[in]); \
numVertices++; \
}
#define DIFFERENT_SIGNS(x,y) ((x <= 0 && y > 0) || (x > 0 && y <= 0))
#define CLIP_DOTPROD(I, A, B, C, D) \
(Vertices[I]->clippos.x * A + Vertices[I]->clippos.y * B + Vertices[I]->clippos.z * C + Vertices[I]->clippos.w * D)
#define POLY_CLIP( PLANE_BIT, A, B, C, D ) \
{ \
if (mask & PLANE_BIT) { \
int idxPrev = inlist[0]; \
float dpPrev = CLIP_DOTPROD(idxPrev, A, B, C, D ); \
int outcount = 0; \
\
inlist[n] = inlist[0]; \
for (int j = 1; j <= n; j++) { \
int idx = inlist[j]; \
float dp = CLIP_DOTPROD(idx, A, B, C, D ); \
if (dpPrev >= 0) { \
outlist[outcount++] = idxPrev; \
} \
\
if (DIFFERENT_SIGNS(dp, dpPrev)) { \
if (dp < 0) { \
float t = dp / (dp - dpPrev); \
AddInterpolatedVertex(t, idx, idxPrev, numVertices); \
} else { \
float t = dpPrev / (dpPrev - dp); \
AddInterpolatedVertex(t, idxPrev, idx, numVertices); \
} \
outlist[outcount++] = numVertices - 1; \
} \
\
idxPrev = idx; \
dpPrev = dp; \
} \
\
if (outcount < 3) \
continue; \
\
{ \
int *tmp = inlist; \
inlist = outlist; \
outlist = tmp; \
n = outcount; \
} \
} \
}
#define CLIP_LINE(PLANE_BIT, A, B, C, D) \
{ \
if (mask & PLANE_BIT) { \
float dp0 = CLIP_DOTPROD(0, A, B, C, D ); \
float dp1 = CLIP_DOTPROD(1, A, B, C, D ); \
int i = 0; \
\
if (mask0 & PLANE_BIT) { \
if (dp0 < 0) { \
float t = dp1 / (dp1 - dp0); \
i = 0; \
AddInterpolatedVertex(t, 1, 0, i); \
} \
} \
dp0 = CLIP_DOTPROD(0, A, B, C, D ); \
\
if (mask1 & PLANE_BIT) { \
if (dp1 < 0) { \
float t = dp1 / (dp1- dp0); \
i = 1; \
AddInterpolatedVertex(t, 1, 0, i); \
} \
} \
} \
}
static void RotateUVThrough(const VertexData &tl, const VertexData &br, VertexData &tr, VertexData &bl) {
const fixed16 x1 = tl.screenpos.x;
const fixed16 x2 = br.screenpos.x;
const fixed16 y1 = tl.screenpos.y;
const fixed16 y2 = br.screenpos.y;
if ((x1 < x2 && y1 > y2) || (x1 > x2 && y1 < y2)) {
std::swap(bl.texturecoords, tr.texturecoords);
}
}
void ProcessRect(const VertexData& v0, const VertexData& v1)
{
if (!gstate.isModeThrough()) {
VertexData buf[4];
buf[0].clippos = ClipCoords(v0.clippos.x, v0.clippos.y, v1.clippos.z, v1.clippos.w);
buf[0].texturecoords = v0.texturecoords;
buf[1].clippos = ClipCoords(v0.clippos.x, v1.clippos.y, v1.clippos.z, v1.clippos.w);
buf[1].texturecoords = Vec2<float>(v0.texturecoords.x, v1.texturecoords.y);
buf[2].clippos = ClipCoords(v1.clippos.x, v0.clippos.y, v1.clippos.z, v1.clippos.w);
buf[2].texturecoords = Vec2<float>(v1.texturecoords.x, v0.texturecoords.y);
buf[3] = v1;
// Color and depth values of second vertex are used for the whole rectangle
buf[0].color0 = buf[1].color0 = buf[2].color0 = buf[3].color0;
buf[0].color1 = buf[1].color1 = buf[2].color1 = buf[3].color1;
VertexData* topleft = &buf[0];
VertexData* topright = &buf[1];
VertexData* bottomleft = &buf[2];
VertexData* bottomright = &buf[3];
for (int i = 0; i < 4; ++i) {
if (buf[i].clippos.x < topleft->clippos.x && buf[i].clippos.y < topleft->clippos.y)
topleft = &buf[i];
if (buf[i].clippos.x > topright->clippos.x && buf[i].clippos.y < topright->clippos.y)
topright = &buf[i];
if (buf[i].clippos.x < bottomleft->clippos.x && buf[i].clippos.y > bottomleft->clippos.y)
bottomleft = &buf[i];
if (buf[i].clippos.x > bottomright->clippos.x && buf[i].clippos.y > bottomright->clippos.y)
bottomright = &buf[i];
}
// Four triangles to do backfaces as well. Two of them will get backface culled.
ProcessTriangle(*topleft, *topright, *bottomright);
ProcessTriangle(*bottomright, *topright, *topleft);
ProcessTriangle(*bottomright, *bottomleft, *topleft);
ProcessTriangle(*topleft, *bottomleft, *bottomright);
} else {
// through mode handling
VertexData buf[4];
buf[0].screenpos = ScreenCoords(v0.screenpos.x, v0.screenpos.y, v1.screenpos.z);
buf[0].texturecoords = v0.texturecoords;
buf[1].screenpos = ScreenCoords(v0.screenpos.x, v1.screenpos.y, v1.screenpos.z);
buf[1].texturecoords = Vec2<float>(v0.texturecoords.x, v1.texturecoords.y);
buf[2].screenpos = ScreenCoords(v1.screenpos.x, v0.screenpos.y, v1.screenpos.z);
buf[2].texturecoords = Vec2<float>(v1.texturecoords.x, v0.texturecoords.y);
buf[3] = v1;
// Color and depth values of second vertex are used for the whole rectangle
buf[0].color0 = buf[1].color0 = buf[2].color0 = buf[3].color0;
buf[0].color1 = buf[1].color1 = buf[2].color1 = buf[3].color1;
buf[0].clippos.w = buf[1].clippos.w = buf[2].clippos.w = buf[3].clippos.w = 1.0f;
buf[0].fogdepth = buf[1].fogdepth = buf[2].fogdepth = buf[3].fogdepth = 1.0f;
VertexData* topleft = &buf[0];
VertexData* topright = &buf[1];
VertexData* bottomleft = &buf[2];
VertexData* bottomright = &buf[3];
// Um. Why is this stuff needed?
for (int i = 0; i < 4; ++i) {
if (buf[i].screenpos.x < topleft->screenpos.x && buf[i].screenpos.y < topleft->screenpos.y)
topleft = &buf[i];
if (buf[i].screenpos.x > topright->screenpos.x && buf[i].screenpos.y < topright->screenpos.y)
topright = &buf[i];
if (buf[i].screenpos.x < bottomleft->screenpos.x && buf[i].screenpos.y > bottomleft->screenpos.y)
bottomleft = &buf[i];
if (buf[i].screenpos.x > bottomright->screenpos.x && buf[i].screenpos.y > bottomright->screenpos.y)
bottomright = &buf[i];
}
RotateUVThrough(v0, v1, *topright, *bottomleft);
// Four triangles to do backfaces as well. Two of them will get backface culled.
Rasterizer::DrawTriangle(*topleft, *topright, *bottomright);
Rasterizer::DrawTriangle(*bottomright, *topright, *topleft);
Rasterizer::DrawTriangle(*bottomright, *bottomleft, *topleft);
Rasterizer::DrawTriangle(*topleft, *bottomleft, *bottomright);
}
}
void ProcessPoint(VertexData& v0)
{
// Points need no clipping. Will be bounds checked in the rasterizer (which seems backwards?)
Rasterizer::DrawPoint(v0);
}
void ProcessLine(VertexData& v0, VertexData& v1)
{
if (gstate.isModeThrough()) {
// Actually, should clip this one too so we don't need to do bounds checks in the rasterizer.
Rasterizer::DrawLine(v0, v1);
return;
}
// TODO: 3D lines
}
void ProcessTriangle(VertexData& v0, VertexData& v1, VertexData& v2)
{
if (gstate.isModeThrough()) {
Rasterizer::DrawTriangle(v0, v1, v2);
return;
}
enum { NUM_CLIPPED_VERTICES = 33, NUM_INDICES = NUM_CLIPPED_VERTICES + 3 };
VertexData* Vertices[NUM_INDICES];
VertexData ClippedVertices[NUM_CLIPPED_VERTICES];
for (int i = 0; i < NUM_CLIPPED_VERTICES; ++i)
Vertices[i+3] = &ClippedVertices[i];
// TODO: Change logic when it's a backface (why? In what way?)
Vertices[0] = &v0;
Vertices[1] = &v1;
Vertices[2] = &v2;
int indices[NUM_INDICES] = { 0, 1, 2, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG,
SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG,
SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG };
int numIndices = 3;
int mask = 0;
mask |= CalcClipMask(v0.clippos);
mask |= CalcClipMask(v1.clippos);
mask |= CalcClipMask(v2.clippos);
if (mask && (gstate.clipEnable & 0x1)) {
// discard if any vertex is outside the near clipping plane
if (mask & CLIP_NEG_Z_BIT)
return;
for (int i = 0; i < 3; i += 3) {
int vlist[2][2*6+1];
int *inlist = vlist[0], *outlist = vlist[1];
int n = 3;
int numVertices = 3;
inlist[0] = 0;
inlist[1] = 1;
inlist[2] = 2;
// mark this triangle as unused in case it should be completely clipped
indices[0] = SKIP_FLAG;
indices[1] = SKIP_FLAG;
indices[2] = SKIP_FLAG;
POLY_CLIP(CLIP_POS_X_BIT, -1, 0, 0, 1);
POLY_CLIP(CLIP_NEG_X_BIT, 1, 0, 0, 1);
POLY_CLIP(CLIP_POS_Y_BIT, 0, -1, 0, 1);
POLY_CLIP(CLIP_NEG_Y_BIT, 0, 1, 0, 1);
POLY_CLIP(CLIP_POS_Z_BIT, 0, 0, 0, 1);
POLY_CLIP(CLIP_NEG_Z_BIT, 0, 0, 1, 1);
// transform the poly in inlist into triangles
indices[0] = inlist[0];
indices[1] = inlist[1];
indices[2] = inlist[2];
for (int j = 3; j < n; ++j) {
indices[numIndices++] = inlist[0];
indices[numIndices++] = inlist[j - 1];
indices[numIndices++] = inlist[j];
}
}
} else if (CalcClipMask(v0.clippos) & CalcClipMask(v1.clippos) & CalcClipMask(v2.clippos)) {
// If clipping is disabled, only discard the current primitive
// if all three vertices lie outside one of the clipping planes
return;
}
for (int i = 0; i+3 <= numIndices; i+=3)
{
if(indices[i] != SKIP_FLAG)
{
VertexData data[3] = { *Vertices[indices[i]], *Vertices[indices[i+1]], *Vertices[indices[i+2]] };
data[0].screenpos = TransformUnit::ClipToScreen(data[0].clippos);
data[1].screenpos = TransformUnit::ClipToScreen(data[1].clippos);
data[2].screenpos = TransformUnit::ClipToScreen(data[2].clippos);
Rasterizer::DrawTriangle(data[0], data[1], data[2]);
}
}
}
} // namespace