/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* vim: set ts=8 sts=4 et sw=4 tw=80: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "DecomposeIntoNoRepeatTriangles.h" #include "gfxMatrix.h" namespace mozilla { namespace gl { void RectTriangles::AppendRectToCoordArray(InfallibleTArray<coord>& array, GLfloat x0, GLfloat y0, GLfloat x1, GLfloat y1) { coord* v = array.AppendElements(6); v[0].x = x0; v[0].y = y0; v[1].x = x1; v[1].y = y0; v[2].x = x0; v[2].y = y1; v[3].x = x0; v[3].y = y1; v[4].x = x1; v[4].y = y0; v[5].x = x1; v[5].y = y1; } void RectTriangles::addRect(GLfloat x0, GLfloat y0, GLfloat x1, GLfloat y1, GLfloat tx0, GLfloat ty0, GLfloat tx1, GLfloat ty1, bool flip_y /* = false */) { if (flip_y) { std::swap(ty0, ty1); } AppendRectToCoordArray(mVertexCoords, x0, y0, x1, y1); AppendRectToCoordArray(mTexCoords, tx0, ty0, tx1, ty1); } static GLfloat WrapTexCoord(GLfloat v) { // This should return values in range [0, 1.0) return v - floorf(v); } void DecomposeIntoNoRepeatTriangles(const gfx::IntRect& aTexCoordRect, const gfx::IntSize& aTexSize, RectTriangles& aRects, bool aFlipY /* = false */) { // normalize this gfx::IntRect tcr(aTexCoordRect); while (tcr.x >= aTexSize.width) tcr.x -= aTexSize.width; while (tcr.y >= aTexSize.height) tcr.y -= aTexSize.height; // Compute top left and bottom right tex coordinates GLfloat tl[2] = { GLfloat(tcr.x) / GLfloat(aTexSize.width), GLfloat(tcr.y) / GLfloat(aTexSize.height) }; GLfloat br[2] = { GLfloat(tcr.XMost()) / GLfloat(aTexSize.width), GLfloat(tcr.YMost()) / GLfloat(aTexSize.height) }; // then check if we wrap in either the x or y axis; if we do, // then also use fmod to figure out the "true" non-wrapping // texture coordinates. bool xwrap = false, ywrap = false; if (tcr.x < 0 || tcr.x > aTexSize.width || tcr.XMost() < 0 || tcr.XMost() > aTexSize.width) { xwrap = true; tl[0] = WrapTexCoord(tl[0]); br[0] = WrapTexCoord(br[0]); } if (tcr.y < 0 || tcr.y > aTexSize.height || tcr.YMost() < 0 || tcr.YMost() > aTexSize.height) { ywrap = true; tl[1] = WrapTexCoord(tl[1]); br[1] = WrapTexCoord(br[1]); } NS_ASSERTION(tl[0] >= 0.0f && tl[0] <= 1.0f && tl[1] >= 0.0f && tl[1] <= 1.0f && br[0] >= 0.0f && br[0] <= 1.0f && br[1] >= 0.0f && br[1] <= 1.0f, "Somehow generated invalid texture coordinates"); // If xwrap is false, the texture will be sampled from tl[0] // .. br[0]. If xwrap is true, then it will be split into tl[0] // .. 1.0, and 0.0 .. br[0]. Same for the Y axis. The // destination rectangle is also split appropriately, according // to the calculated xmid/ymid values. // There isn't a 1:1 mapping between tex coords and destination coords; // when computing midpoints, we have to take that into account. We // need to map the texture coords, which are (in the wrap case): // |tl->1| and |0->br| to the |0->1| range of the vertex coords. So // we have the length (1-tl)+(br) that needs to map into 0->1. // These are only valid if there is wrap involved, they won't be used // otherwise. GLfloat xlen = (1.0f - tl[0]) + br[0]; GLfloat ylen = (1.0f - tl[1]) + br[1]; NS_ASSERTION(!xwrap || xlen > 0.0f, "xlen isn't > 0, what's going on?"); NS_ASSERTION(!ywrap || ylen > 0.0f, "ylen isn't > 0, what's going on?"); NS_ASSERTION(aTexCoordRect.width <= aTexSize.width && aTexCoordRect.height <= aTexSize.height, "tex coord rect would cause tiling!"); if (!xwrap && !ywrap) { aRects.addRect(0.0f, 0.0f, 1.0f, 1.0f, tl[0], tl[1], br[0], br[1], aFlipY); } else if (!xwrap && ywrap) { GLfloat ymid = (1.0f - tl[1]) / ylen; aRects.addRect(0.0f, 0.0f, 1.0f, ymid, tl[0], tl[1], br[0], 1.0f, aFlipY); aRects.addRect(0.0f, ymid, 1.0f, 1.0f, tl[0], 0.0f, br[0], br[1], aFlipY); } else if (xwrap && !ywrap) { GLfloat xmid = (1.0f - tl[0]) / xlen; aRects.addRect(0.0f, 0.0f, xmid, 1.0f, tl[0], tl[1], 1.0f, br[1], aFlipY); aRects.addRect(xmid, 0.0f, 1.0f, 1.0f, 0.0f, tl[1], br[0], br[1], aFlipY); } else { GLfloat xmid = (1.0f - tl[0]) / xlen; GLfloat ymid = (1.0f - tl[1]) / ylen; aRects.addRect(0.0f, 0.0f, xmid, ymid, tl[0], tl[1], 1.0f, 1.0f, aFlipY); aRects.addRect(xmid, 0.0f, 1.0f, ymid, 0.0f, tl[1], br[0], 1.0f, aFlipY); aRects.addRect(0.0f, ymid, xmid, 1.0f, tl[0], 0.0f, 1.0f, br[1], aFlipY); aRects.addRect(xmid, ymid, 1.0f, 1.0f, 0.0f, 0.0f, br[0], br[1], aFlipY); } } } // namespace gl } // namespace mozilla