private List <Fragment> LinearInterpolation(DrawTarget mode, int count, DrawElementsType type, IntPtr indices, VertexArrayObject vao, ShaderProgram program, GLBuffer indexBuffer, PassBuffer[] passBuffers)
{
List <Fragment> result = null;
switch (mode)
{
case DrawTarget.Points: result = LinearInterpolationPoints(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.Lines: result = LinearInterpolationLines(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.LineLoop: result = LinearInterpolationLineLoop(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.LineStrip: result = LinearInterpolationLineStrip(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.Triangles: result = LinearInterpolationTriangles(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.TriangleStrip: result = LinearInterpolationTriangleStrip(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.TriangleFan: result = LinearInterpolationTriangleFan(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.Quads: result = LinearInterpolationQuads(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.QuadStrip: result = LinearInterpolationQuadStrip(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.Polygon: result = LinearInterpolationPolygon(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.LinesAdjacency: result = LinearInterpolationLinesAdjacency(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.LineStripAdjacency: result = LinearInterpolationLineStripAdjacency(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.TrianglesAdjacency: result = LinearInterpolationTrianglesAdjacency(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.TriangleStripAdjacency: result = LinearInterpolationTriangleStripAdjacency(count, type, indices, vao, program, indexBuffer, passBuffers); break;
case DrawTarget.Patches: result = LinearInterpolationPatches(count, type, indices, vao, program, indexBuffer, passBuffers); break;
default: throw new NotDealWithNewEnumItemException(typeof(DrawTarget));
}
return(result);
}
private unsafe List <Fragment> LinearInterpolationQuadStrip(int count, DrawElementsType type, IntPtr indices, VertexArrayObject vao, ShaderProgram program, GLBuffer indexBuffer, PassBuffer[] passBuffers)
{
var result = new List <Fragment>();
var gl_PositionArray = (vec4 *)passBuffers[0].Mapbuffer().ToPointer();
var pointers = new void *[passBuffers.Length - 1];
for (int i = 0; i < pointers.Length; i++)
{
pointers[i] = passBuffers[i + 1].Mapbuffer().ToPointer();
}
byte[] indexData = indexBuffer.Data;
int indexLength = indexData.Length / ByteLength(type);
GCHandle pin = GCHandle.Alloc(indexData, GCHandleType.Pinned);
IntPtr pointer = pin.AddrOfPinnedObject();
var groupList = new List <LinearInterpolationInfoGroup>();
ivec4 viewport = this.viewport; // ivec4(x, y, width, height)
count = (count - count % 2);
for (int indexID = indices.ToInt32() / ByteLength(type), c = 0; c < count - 3 && indexID < indexLength - 3; indexID += 2, c += 2)
{
var group = new LinearInterpolationInfoGroup(4);
for (int i = 0; i < 4; i++)
{
uint gl_VertexID = GetVertexID(pointer, type, indexID + i);
vec4 gl_Position = gl_PositionArray[gl_VertexID];
vec3 fragCoord = new vec3((gl_Position.x + 1) / 2.0f * viewport.z + viewport.x,
(gl_Position.y + 1) / 2.0f * viewport.w + viewport.y,
(gl_Position.z + 1) / 2.0f * (float)(this.depthRangeFar - this.depthRangeNear) + (float)this.depthRangeNear);
group.array[i] = new LinearInterpolationInfo(gl_VertexID, fragCoord);
}
if (groupList.Contains(group))
{
continue;
} // discard the same line.
else
{
groupList.Add(group);
}
vec3 fragCoord0 = group.array[0].fragCoord;
vec3 fragCoord1 = group.array[1].fragCoord;
vec3 fragCoord2 = group.array[2].fragCoord;
vec3 fragCoord3 = group.array[3].fragCoord;
FindFragmentsInTriangle(fragCoord0, fragCoord1, fragCoord2, pointers, group, passBuffers, result);
FindFragmentsInTriangle(fragCoord1, fragCoord3, fragCoord2, pointers, group, passBuffers, result);
}
for (int i = 0; i < passBuffers.Length; i++)
{
passBuffers[i].Unmapbuffer();
}
return(result);
}
private void DrawElements(DrawTarget mode, int count, DrawElementsType type, IntPtr indices)
{
if (!Enum.IsDefined(typeof(DrawTarget), mode) || !Enum.IsDefined(typeof(DrawElementsType), type))
{
SetLastError(ErrorCode.InvalidEnum); return;
}
if (count < 0)
{
SetLastError(ErrorCode.InvalidValue); return;
}
// TODO: GL_INVALID_OPERATION is generated if a geometry shader is active and mode is incompatible with the input primitive type of the geometry shader in the currently installed program object.
// TODO: GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array or the element array and the buffer object's data store is currently mapped.
VertexArrayObject vao = this.currentVertexArrayObject; // data structure.
if (vao == null)
{
return;
}
ShaderProgram program = this.currentShaderProgram; // algorithm.
if (program == null)
{
return;
}
GLBuffer indexBuffer = this.currentBufferDict[BindBufferTarget.ElementArrayBuffer];
if (indexBuffer == null)
{
return;
}
// execute vertex shader for each vertex!
// This is a low effetient implementation.
// passBuffers is input for the next stage: linear interpolation.
// passBuffers[0] is gl_Position.
// passBuffers[others] are attributes of vertexes.
PassBuffer[] passBuffers = VertexShaderStage(count, type, indices, vao, program, indexBuffer);
if (passBuffers == null)
{
return;
} // this stage failed.
Framebuffer framebuffer = this.currentFramebuffer;
if (framebuffer == null)
{
throw new Exception("This should not happen!");
}
ClipSpace2NormalDeviceSpace(passBuffers[0]);
// linear interpolation.
List <Fragment> fragmentList = LinearInterpolation(mode, count, type, indices, vao, program, indexBuffer, passBuffers);
// execute fargment shader for each fragment!
// This is a low effetient implementation.
FragmentShaderStage(program, fragmentList);
{
int index = 0;
while (index < fragmentList.Count)
{
if (fragmentList[index].discard)
{
fragmentList.RemoveAt(index);
}
else
{
index++;
}
}
}
// Scissor test
// Multisampel fragment operations
// Stencil test
// Depth test
DepthTest(fragmentList);
//Blending
// Dithering
// Logical operations
// write fragments to framebuffer's colorbuffer attachment(s).
{
uint[] drawBufferIndexes = framebuffer.DrawBuffers.ToArray();
foreach (var fragment in fragmentList)
{
if (fragment.depthTestFailed)
{
continue;
}
for (int i = 0; i < fragment.outVariables.Length && i < drawBufferIndexes.Length; i++)
{
PassBuffer outVar = fragment.outVariables[i];
IAttachable attachment = framebuffer.ColorbufferAttachments[drawBufferIndexes[i].ToIndex()];
attachment.Set((int)fragment.gl_FragCoord.x, (int)fragment.gl_FragCoord.y, outVar);
}
}
}
}