renderTriangle method

void renderTriangle(RenderState renderState, num x1, num y1, num x2, num y2, num x3, num y3, int color,)

Implementation

void renderTriangle(RenderState renderState, num x1, num y1, num x2, num y2,
    num x3, num y3, int color) {
  final matrix = renderState.globalMatrix;
  final alpha = renderState.globalAlpha;
  const indexCount = 3;
  const vertexCount = 3;

  // check buffer sizes and flush if necessary

  final ixData = renderBufferIndex.data;
  final ixPosition = renderBufferIndex.position;
  if (ixPosition + indexCount >= ixData.length) flush();

  final vxData = renderBufferVertex.data;
  final vxPosition = renderBufferVertex.position;
  if (vxPosition + vertexCount * 6 >= vxData.length) flush();

  final ixIndex = renderBufferIndex.position;
  final vxIndex = renderBufferVertex.position;
  final vxCount = renderBufferVertex.count;

  // fill index buffer

  ixData[ixIndex + 0] = vxCount + 0;
  ixData[ixIndex + 1] = vxCount + 1;
  ixData[ixIndex + 2] = vxCount + 2;

  renderBufferIndex.position += indexCount;
  renderBufferIndex.count += indexCount;

  // fill vertex buffer

  final ma = matrix.a;
  final mb = matrix.b;
  final mc = matrix.c;
  final md = matrix.d;
  final mx = matrix.tx;
  final my = matrix.ty;

  const colorScale = 1 / 255.0;
  final colorA = colorScale * colorGetA(color) * alpha;
  final colorR = colorScale * colorGetR(color) * colorA;
  final colorG = colorScale * colorGetG(color) * colorA;
  final colorB = colorScale * colorGetB(color) * colorA;

  vxData[vxIndex + 00] = x1 * ma + y1 * mc + mx;
  vxData[vxIndex + 01] = x1 * mb + y1 * md + my;
  vxData[vxIndex + 02] = colorR;
  vxData[vxIndex + 03] = colorG;
  vxData[vxIndex + 04] = colorB;
  vxData[vxIndex + 05] = colorA;

  vxData[vxIndex + 06] = x2 * ma + y2 * mc + mx;
  vxData[vxIndex + 07] = x2 * mb + y2 * md + my;
  vxData[vxIndex + 08] = colorR;
  vxData[vxIndex + 09] = colorG;
  vxData[vxIndex + 10] = colorB;
  vxData[vxIndex + 11] = colorA;

  vxData[vxIndex + 12] = x3 * ma + y3 * mc + mx;
  vxData[vxIndex + 13] = x3 * mb + y3 * md + my;
  vxData[vxIndex + 14] = colorR;
  vxData[vxIndex + 15] = colorG;
  vxData[vxIndex + 16] = colorB;
  vxData[vxIndex + 17] = colorA;

  renderBufferVertex.position += vertexCount * 6;
  renderBufferVertex.count += vertexCount;
}