ppsspp/GPU/Software/Rasterizer.cpp

90 lines
2.4 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 "../GPUState.h"
#include "Rasterizer.h"
const int FB_WIDTH = 480;
const int FB_HEIGHT = 272;
extern u8* fb;
namespace Rasterizer {
static void DrawVLine(u8* target, DrawingCoords a, DrawingCoords b)
{
if (a.y > b.y) {
DrawVLine(target, b, a);
return;
}
for (int y = a.y; y < b.y; ++y) {
float u = (float)(y-a.y)/(float)(b.y-a.y);
int x = (1-u)*a.x+u*b.x;
if (x < gstate.getScissorX1()) continue;
if (x > gstate.getScissorX2()) continue;
if (y < gstate.getScissorY1()) continue;
if (y > gstate.getScissorY2()) continue;
target[x*4+y*FB_WIDTH*4] = 0xff;
target[x*4+y*FB_WIDTH*4+1] = 0xff;
target[x*4+y*FB_WIDTH*4+2] = 0xff;
target[x*4+y*FB_WIDTH*4+3] = 0xff;
}
}
static void DrawLine(u8* target, DrawingCoords a, DrawingCoords b)
{
if (a.x > b.x) {
DrawLine(target, b, a);
return;
}
if (a.y > b.y && a.x - b.x < a.y - b.y)
{
DrawVLine(target, a, b);
return;
}
if (a.y < b.y && a.x - b.x < b.y - a.y)
{
DrawVLine(target, a, b);
return;
}
for (int x = a.x; x < b.x; ++x) {
float u = (float)(x-a.x)/(float)(b.x-a.x);
int y = (1-u)*a.y+u*b.y;
if (x < gstate.getScissorX1()) continue;
if (x > gstate.getScissorX2()) continue;
if (y < gstate.getScissorY1()) continue;
if (y > gstate.getScissorY2()) continue;
target[x*4+y*FB_WIDTH*4] = 0xff;
target[x*4+y*FB_WIDTH*4+1] = 0xff;
target[x*4+y*FB_WIDTH*4+2] = 0xff;
target[x*4+y*FB_WIDTH*4+3] = 0xff;
}
}
void DrawTriangle(DrawingCoords vertices[3])
{
// TODO: Well yeah, that's not quite it, yet.. :p
DrawLine(fb, vertices[0], vertices[1]);
DrawLine(fb, vertices[1], vertices[2]);
DrawLine(fb, vertices[2], vertices[0]);
}
} // namespace