public void FixedTransform(PrimitiveContext ctx, vec4[] in_vertices, int indexBase, int indexTo)
{
vec4 ret = ModelMatrix * in_vertices[indexBase];
ret = ViewMatrix * ret;
ret = ProjectionMatrix * ret;
ctx.w[indexTo] = ret.w;
if (ret.w != 0)
{
ret = ret / ret.w;
}
ret.x = (ret.x + 1f) * Viewport.Width * 0.5f;
ret.y = (1f - ret.y) * Viewport.Height * 0.5f;
ctx.v[indexTo] = ret;
}
public void Clear()
{
ModelMatrix = mat4.Identity;
ViewMatrix = mat4.Identity;
ProjectionMatrix = mat4.Identity;
DisposeBackBuffer();
SetTarget(null);
DepthBuffer = null;
m_PrimiteContext = null;
bDrawWrireframe = true;
bDrawPrimitive = true;
TextureBlendFactor = 0.75f;
}
private void DrawTrianguleWireframe(PrimitiveContext context)
{
int[,] edges = { { 0, 1 }, { 1, 2 }, { 2, 0 } };
vec4 cor = new vec4(0f, 1f, 0f, 1f);
for (int e = 0; e < 3; e++)
{
vec4 v0 = context.v[edges[e, 0]];
vec4 v1 = context.v[edges[e, 1]];
vec4 diff = (v0 - v1);
int maxPoints = glm.Max(10, (int)(Math.Abs(diff.x) + Math.Abs(diff.y) + 1));
for (int valor = 0; valor < maxPoints; valor++)
{
float alpha = ((float)valor / (float)maxPoints);
vec4 ponto = vec4.Mix(v0, v1, alpha);
DrawPoint(ponto, Util.ToARGB(cor));
}
}
}
public void glDrawPrimitives(int baseIndex, int numPrimitives, vec4[] in_vertices, vec4[] in_colors, vec2[] in_textCoords)
{
int primitiveSize = 3;
int index = baseIndex;
if (m_PrimiteContext == null)
{
m_PrimiteContext = new PrimitiveContext(this);
}
m_PrimiteContext.bverts = in_vertices;
m_PrimiteContext.bcolors = in_colors;
m_PrimiteContext.btc = in_textCoords;
for (int primitive = 0; primitive < numPrimitives; primitive++)
{
m_PrimiteContext.Reset();
m_PrimiteContext.baseIndex = index;
for (int v = 0; v < primitiveSize; v++)
{
FixedTransform(m_PrimiteContext, in_vertices, index + v, v);
}
if (bDrawPrimitive)
{
DrawTriangule(m_PrimiteContext);
}
if (bDrawWrireframe)
{
DrawTrianguleWireframe(m_PrimiteContext);
}
index += primitiveSize;
}
}
private void DrawScanLine(PrimitiveContext ctx, int y, float xe, float xd)
{
int xmin = glm.Max((int)xe, 0);
int xmax = glm.Min((int)xd, Viewport.Width);
int ib = ctx.baseIndex;
float w0 = ctx.w[ctx.iV0];
float w1 = ctx.w[ctx.iV1];
float w2 = ctx.w[ctx.iV2];
vec4 C0 = ctx.bcolors[ib + ctx.iV0];
vec4 C1 = ctx.bcolors[ib + ctx.iV1];
vec4 C2 = ctx.bcolors[ib + ctx.iV2];
vec2 T0 = ctx.btc[ib + ctx.iV0];
vec2 T1 = ctx.btc[ib + ctx.iV1];
vec2 T2 = ctx.btc[ib + ctx.iV2];
float dn01 = Linear2Homo(ctx.dfd01, w0, w1);
float dn12 = Linear2Homo(ctx.dfd12, w1, w2);
float dn02 = Linear2Homo(ctx.dfe02, w0, w2);
float dn21 = Linear2Homo(ctx.dfe21, w2, w1);
float dr01 = 1f - dn01;
float dr12 = 1f - dn12;
float dr02 = 1f - dn02;
float dr21 = 1f - dn21;
float bn012 = ctx.dfd012;
float bn021 = ctx.dfe021;
float br012 = 1f - bn012;
float br021 = 1f - bn021;
float R0 = dr01 * br012;
float R1 = dr02 * br021;
float R23 = dn01 * br012 + dr12 * bn012;
float R4 = dn21 * bn021;
float R5 = dn12 * bn012;
float R67 = dn02 * br021 + dr21 * bn021;
float wLeft = w0 * R1 + w1 * R4 + w2 * R67;
float wRight = w0 * R0 + w1 * R23 + w2 * R5;
vec4 CE = C0 * R1 + C1 * R4 + C2 * R67;
vec4 CD = C0 * R0 + C1 * R23 + C2 * R5;
vec2 TE = T0 * R1 + T1 * R4 + T2 * R67;
vec2 TD = T0 * R0 + T1 * R23 + T2 * R5;
float zLeft = ctx.v[ctx.iV0].z * R1 + ctx.v[ctx.iV1].z * R4 + ctx.v[ctx.iV2].z * R67;
float zRight = ctx.v[ctx.iV0].z * R0 + ctx.v[ctx.iV1].z * R23 + ctx.v[ctx.iV2].z * R5;
vec4 CDE = CD - CE;
vec2 TDE = TD - TE;
float deltaDx = (xd != xe) ? 1f / (float)(xd - xe) : 0f;
for (int x = xmin; x <= xmax; x++)
{
float dx = (float)(x - xe) * deltaDx;
dx = Linear2Homo(dx, wLeft, wRight);
float z = zLeft + (zRight - zLeft) * dx;
if (z >= DepthBuffer.GetPoint(x, y))
{
continue;
}
DepthBuffer.SetPoint(x, y, z);
vec4 vertexColor = CE + (CDE * dx);
vec2 textureCoord = TE + (TDE * dx);
vec4 textureColor = CurrentTexture.GetTexel(textureCoord.x, textureCoord.y);
vec4 color = vec4.Mix(vertexColor, textureColor, TextureBlendFactor);
DrawPoint(x, y, Util.ToARGB(color));
}
}
private void DrawTriangule(PrimitiveContext ctx)
{
int itop = 0;
if (ctx.v[ctx.iV1].y < ctx.v[itop].y)
{
itop = ctx.iV1;
}
if (ctx.v[ctx.iV2].y < ctx.v[itop].y)
{
itop = ctx.iV2;
}
ctx.iV0 = itop;
ctx.iV1 = (itop + 1) % 3;
ctx.iV2 = (itop + 2) % 3;
ctx.Slope01 = GetSlope(ctx.v, ctx.iV0, ctx.iV1);
ctx.Slope02 = GetSlope(ctx.v, ctx.iV0, ctx.iV2);
ctx.Slope12 = GetSlope(ctx.v, ctx.iV1, ctx.iV2);
ctx.Slope21 = GetSlope(ctx.v, ctx.iV2, ctx.iV1);
if (ctx.Slope02 > ctx.Slope01)
{
int t = ctx.iV1;
ctx.iV1 = ctx.iV2;
ctx.iV2 = t;
ctx.Slope01 = GetSlope(ctx.v, ctx.iV0, ctx.iV1);
ctx.Slope02 = GetSlope(ctx.v, ctx.iV0, ctx.iV2);
ctx.Slope12 = GetSlope(ctx.v, ctx.iV1, ctx.iV2);
ctx.Slope21 = GetSlope(ctx.v, ctx.iV2, ctx.iV1);
}
int minY = (int)ctx.v[ctx.iV0].y;
int maxY = (int)Math.Max(ctx.v[ctx.iV1].y, ctx.v[ctx.iV2].y);
int startY = (minY < 0 ? 0 : minY);
int endY = (maxY >= this.Viewport.Height ? this.Viewport.Height - 1 : maxY);
float yv0 = ctx.v[ctx.iV0].y;
float yv1 = ctx.v[ctx.iV1].y;
float yv2 = ctx.v[ctx.iV2].y;
float xv0 = ctx.v[ctx.iV0].x;
float xv1 = ctx.v[ctx.iV1].x;
float xv2 = ctx.v[ctx.iV2].x;
bool bEqY01 = (yv0 == yv1);
bool bEqY12 = (yv1 == yv2);
bool bEqY20 = (yv2 == yv0);
float dy12 = bEqY12 ? 0f : 1f / (yv1 - yv2);
float dy20 = bEqY20 ? 0f : 1f / (yv2 - yv0);
float dy21 = bEqY12 ? 0f : 1f / (yv2 - yv1);
float dy10 = bEqY01 ? 0f : 1f / (yv1 - yv0);
float xe;
float xd;
float delta;
for (int y = startY; y <= endY; y++)
{
if ((!bEqY12) && (y > yv2 || bEqY20))
{
xe = xv2 + ((y - yv2) * ctx.Slope21);
ctx.dfe021 = 1f;
delta = (y - yv2) * dy12;
ctx.dfe21 = glm.Clamp(delta, 0f, 1f);
}
else if (!bEqY20)
{
xe = xv0 + ((y - yv0) * ctx.Slope02);
ctx.dfe021 = 0f;
delta = (y - yv0) * dy20;
ctx.dfe02 = glm.Clamp(delta, 0f, 1f);
}
else
{
continue;
}
if ((!bEqY12) && (y > yv1 || bEqY01))
{
xd = xv1 + ((y - yv1) * ctx.Slope12);
ctx.dfd012 = 1f;
delta = (y - yv1) * dy21;
ctx.dfd12 = glm.Clamp(delta, 0f, 1f);
}
else if (!bEqY01)
{
xd = xv0 + ((y - yv0) * ctx.Slope01);
ctx.dfd012 = 0f;
delta = (y - yv0) * dy10;
ctx.dfd01 = glm.Clamp(delta, 0f, 1f);
}
else
{
continue;
}
DrawScanLine(ctx, y, xe, xd);
}
}