// Copyright (C) 2002-2012 Nikolaus Gebhardt // This file is part of the "Irrlicht Engine". // For conditions of distribution and use, see copyright notice in irrlicht.h #include "IrrCompileConfig.h" #include "CTRTextureGouraud.h" #ifdef _IRR_COMPILE_WITH_SOFTWARE_ namespace irr { namespace video { class CTRFlat : public CTRTextureGouraud { public: CTRFlat(IZBuffer* zbuffer) : CTRTextureGouraud(zbuffer) { #ifdef _DEBUG setDebugName("CTRFlat"); #endif } //! draws an indexed triangle list virtual void drawIndexedTriangleList(S2DVertex* vertices, s32 vertexCount, const u16* indexList, s32 triangleCount) _IRR_OVERRIDE_ { const S2DVertex *v1, *v2, *v3; u16 color; f32 tmpDiv; // temporary division factor f32 longest; // saves the longest span s32 height; // saves height of triangle u16* targetSurface; // target pointer where to plot pixels s32 spanEnd; // saves end of spans f32 leftdeltaxf; // amount of pixels to increase on left side of triangle f32 rightdeltaxf; // amount of pixels to increase on right side of triangle s32 leftx, rightx; // position where we are f32 leftxf, rightxf; // same as above, but as f32 values s32 span; // current span u16 *hSpanBegin, *hSpanEnd; // pointer used when plotting pixels core::rect TriangleRect; s32 leftZValue, rightZValue; s32 leftZStep, rightZStep; s32 spanZValue, spanZStep; // ZValues when drawing a span TZBufferType* zTarget, *spanZTarget; // target of ZBuffer; lockedSurface = (u16*)RenderTarget->getData(); lockedZBuffer = ZBuffer->lock(); for (s32 i=0; iPos.X - v1->Pos.X) * (v3->Pos.Y - v2->Pos.Y)) - ((v3->Pos.Y - v1->Pos.Y) * (v3->Pos.X - v2->Pos.X)); if (z < 0) continue; } //near plane clipping if (v1->ZValue<0 && v2->ZValue<0 && v3->ZValue<0) continue; // sort for width for inscreen clipping if (v1->Pos.X > v2->Pos.X) swapVertices(&v1, &v2); if (v1->Pos.X > v3->Pos.X) swapVertices(&v1, &v3); if (v2->Pos.X > v3->Pos.X) swapVertices(&v2, &v3); if ((v1->Pos.X - v3->Pos.X) == 0) continue; TriangleRect.UpperLeftCorner.X = v1->Pos.X; TriangleRect.LowerRightCorner.X = v3->Pos.X; // sort for height for faster drawing. if (v1->Pos.Y > v2->Pos.Y) swapVertices(&v1, &v2); if (v1->Pos.Y > v3->Pos.Y) swapVertices(&v1, &v3); if (v2->Pos.Y > v3->Pos.Y) swapVertices(&v2, &v3); TriangleRect.UpperLeftCorner.Y = v1->Pos.Y; TriangleRect.LowerRightCorner.Y = v3->Pos.Y; if (!TriangleRect.isRectCollided(ViewPortRect)) continue; // calculate height of triangle height = v3->Pos.Y - v1->Pos.Y; if (!height) continue; // calculate longest span longest = (v2->Pos.Y - v1->Pos.Y) / (f32)height * (v3->Pos.X - v1->Pos.X) + (v1->Pos.X - v2->Pos.X); spanEnd = v2->Pos.Y; span = v1->Pos.Y; leftxf = (f32)v1->Pos.X; rightxf = (f32)v1->Pos.X; leftZValue = v1->ZValue; rightZValue = v1->ZValue; color = v1->Color; targetSurface = lockedSurface + span * SurfaceWidth; zTarget = lockedZBuffer + span * SurfaceWidth; if (longest < 0.0f) { tmpDiv = 1.0f / (f32)(v2->Pos.Y - v1->Pos.Y); rightdeltaxf = (v2->Pos.X - v1->Pos.X) * tmpDiv; rightZStep = (s32)((v2->ZValue - v1->ZValue) * tmpDiv); tmpDiv = 1.0f / (f32)height; leftdeltaxf = (v3->Pos.X - v1->Pos.X) * tmpDiv; leftZStep = (s32)((v3->ZValue - v1->ZValue) * tmpDiv); } else { tmpDiv = 1.0f / (f32)height; rightdeltaxf = (v3->Pos.X - v1->Pos.X) * tmpDiv; rightZStep = (s32)((v3->ZValue - v1->ZValue) * tmpDiv); tmpDiv = 1.0f / (f32)(v2->Pos.Y - v1->Pos.Y); leftdeltaxf = (v2->Pos.X - v1->Pos.X) * tmpDiv; leftZStep = (s32)((v2->ZValue - v1->ZValue) * tmpDiv); } // do it twice, once for the first half of the triangle, // end then for the second half. for (s32 triangleHalf=0; triangleHalf<2; ++triangleHalf) { if (spanEnd > ViewPortRect.LowerRightCorner.Y) spanEnd = ViewPortRect.LowerRightCorner.Y; // if the span <0, than we can skip these spans, // and proceed to the next spans which are really on the screen. if (span < ViewPortRect.UpperLeftCorner.Y) { // we'll use leftx as temp variable if (spanEnd < ViewPortRect.UpperLeftCorner.Y) { leftx = spanEnd - span; span = spanEnd; } else { leftx = ViewPortRect.UpperLeftCorner.Y - span; span = ViewPortRect.UpperLeftCorner.Y; } leftxf += leftdeltaxf*leftx; rightxf += rightdeltaxf*leftx; targetSurface += SurfaceWidth*leftx; zTarget += SurfaceWidth*leftx; leftZValue += leftZStep*leftx; rightZValue += rightZStep*leftx; } // the main loop. Go through every span and draw it. while (span < spanEnd) { leftx = (s32)(leftxf); rightx = (s32)(rightxf + 0.5f); // perform some clipping // TODO: clipping is not correct when leftx is clipped. if (leftxViewPortRect.LowerRightCorner.X) leftx = ViewPortRect.LowerRightCorner.X; if (rightxViewPortRect.LowerRightCorner.X) rightx = ViewPortRect.LowerRightCorner.X; // draw the span if (rightx - leftx != 0) { tmpDiv = 1.0f / (rightx - leftx); spanZValue = leftZValue; spanZStep = (s32)((rightZValue - leftZValue) * tmpDiv); hSpanBegin = targetSurface + leftx; spanZTarget = zTarget + leftx; hSpanEnd = targetSurface + rightx; while (hSpanBegin < hSpanEnd) { if (spanZValue > *spanZTarget) { *spanZTarget = spanZValue; *hSpanBegin = color; } spanZValue += spanZStep; ++hSpanBegin; ++spanZTarget; } } leftxf += leftdeltaxf; rightxf += rightdeltaxf; ++span; targetSurface += SurfaceWidth; zTarget += SurfaceWidth; leftZValue += leftZStep; rightZValue += rightZStep; } if (triangleHalf>0) // break, we've gout only two halves break; // setup variables for second half of the triangle. if (longest < 0.0f) { tmpDiv = 1.0f / (v3->Pos.Y - v2->Pos.Y); rightdeltaxf = (v3->Pos.X - v2->Pos.X) * tmpDiv; rightxf = (f32)v2->Pos.X; rightZValue = v2->ZValue; rightZStep = (s32)((v3->ZValue - v2->ZValue) * tmpDiv); } else { tmpDiv = 1.0f / (v3->Pos.Y - v2->Pos.Y); leftdeltaxf = (v3->Pos.X - v2->Pos.X) * tmpDiv; leftxf = (f32)v2->Pos.X; leftZValue = v2->ZValue; leftZStep = (s32)((v3->ZValue - v2->ZValue) * tmpDiv); } spanEnd = v3->Pos.Y; } } ZBuffer->unlock(); } }; } // end namespace video } // end namespace irr #endif // _IRR_COMPILE_WITH_SOFTWARE_ namespace irr { namespace video { //! creates a flat triangle renderer ITriangleRenderer* createTriangleRendererFlat(IZBuffer* zbuffer) { #ifdef _IRR_COMPILE_WITH_SOFTWARE_ return new CTRFlat(zbuffer); #else return 0; #endif // _IRR_COMPILE_WITH_SOFTWARE_ } } // end namespace video } // end namespace irr