void RenderInputPostprocess::SetBlendMode(GraphicsState & glstate)
{
assert(blendmode != BlendMode::ALPHATEST);
switch (blendmode)
{
case BlendMode::DISABLED:
{
glstate.Disable(GL_ALPHA_TEST);
glstate.Disable(GL_BLEND);
glstate.Disable(GL_SAMPLE_ALPHA_TO_COVERAGE);
}
break;
case BlendMode::ADD:
{
glstate.Disable(GL_ALPHA_TEST);
glstate.Enable(GL_BLEND);
glstate.Disable(GL_SAMPLE_ALPHA_TO_COVERAGE);
glstate.SetBlendFunc(GL_ONE, GL_ONE);
}
break;
case BlendMode::ALPHABLEND:
{
glstate.Disable(GL_ALPHA_TEST);
glstate.Enable(GL_BLEND);
glstate.Disable(GL_SAMPLE_ALPHA_TO_COVERAGE);
glstate.SetBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}
break;
case BlendMode::PREMULTIPLIED_ALPHA:
{
glstate.Disable(GL_ALPHA_TEST);
glstate.Enable(GL_BLEND);
glstate.Disable(GL_SAMPLE_ALPHA_TO_COVERAGE);
glstate.SetBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
}
break;
default:
assert(0);
break;
}
}
void RenderInputPostprocess::Render(GraphicsState & glstate, std::ostream & error_output)
{
assert(shader);
CheckForOpenGLErrors("postprocess begin", error_output);
glstate.SetColorMask(writecolor, writealpha);
glstate.SetDepthMask(writedepth);
if (clearcolor && cleardepth)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
else if (clearcolor)
glClear(GL_COLOR_BUFFER_BIT);
else if (cleardepth)
glClear(GL_DEPTH_BUFFER_BIT);
shader->Enable();
CheckForOpenGLErrors("postprocess shader enable", error_output);
Mat4 projMatrix, viewMatrix;
projMatrix.SetOrthographic(0, 1, 0, 1, -1, 1);
viewMatrix.LoadIdentity();
glMatrixMode(GL_PROJECTION);
glLoadMatrixf(projMatrix.GetArray());
glMatrixMode(GL_MODELVIEW);
glLoadMatrixf(viewMatrix.GetArray());
glstate.SetColor(1,1,1,1);
SetBlendMode(glstate);
if (writedepth || depth_mode != GL_ALWAYS)
glstate.Enable(GL_DEPTH_TEST);
else
glstate.Disable(GL_DEPTH_TEST);
glDepthFunc( depth_mode );
glstate.Enable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_NONE);
glTexParameteri(GL_TEXTURE_2D, GL_DEPTH_TEXTURE_MODE, GL_LUMINANCE);
CheckForOpenGLErrors("postprocess flag set", error_output);
float maxu = 1.f;
float maxv = 1.f;
int num_nonnull = 0;
for (unsigned int i = 0; i < source_textures.size(); i++)
{
//std::cout << i << ": " << source_textures[i] << std::endl;
glActiveTexture(GL_TEXTURE0+i);
if (source_textures[i])
{
source_textures[i]->Activate();
num_nonnull++;
if (source_textures[i]->IsRect())
{
maxu = source_textures[i]->GetW();
maxv = source_textures[i]->GetH();
}
}
}
if (source_textures.size() && !num_nonnull)
{
error_output << "Out of the " << source_textures.size() << " input textures provided as inputs to this postprocess stage, zero are available. This stage will have no effect." << std::endl;
return;
}
glActiveTexture(GL_TEXTURE0);
CheckForOpenGLErrors("postprocess texture set", error_output);
// build the frustum corners
float ratio = w/h;
std::vector <Vec3 > frustum_corners(4);
frustum_corners[0].Set(-lod_far,-lod_far,-lod_far); //BL
frustum_corners[1].Set(lod_far,-lod_far,-lod_far); //BR
frustum_corners[2].Set(lod_far,lod_far,-lod_far); //TR
frustum_corners[3].Set(-lod_far,lod_far,-lod_far); //TL
Mat4 inv_proj;
inv_proj.InvPerspective(camfov, ratio, 0.1, lod_far);
for (int i = 0; i < 4; i++)
{
inv_proj.TransformVectorOut(frustum_corners[i][0], frustum_corners[i][1], frustum_corners[i][2]);
frustum_corners[i][2] = -lod_far;
}
// frustum corners in world space for dynamic sky shader
std::vector <Vec3 > frustum_corners_w(4);
Mat4 inv_view_rot;
(-cam_rotation).GetMatrix4(inv_view_rot);
for (int i = 0; i < 4; i++)
{
frustum_corners_w[i] = frustum_corners[i];
inv_view_rot.TransformVectorOut(frustum_corners_w[i][0], frustum_corners_w[i][1], frustum_corners_w[i][2]);
}
// send shader parameters
{
Vec3 lightvec = lightposition;
cam_rotation.RotateVector(lightvec);
shader->UploadActiveShaderParameter3f("directlight_eyespace_direction", lightvec);
shader->UploadActiveShaderParameter1f("contrast", contrast);
shader->UploadActiveShaderParameter1f("znear", 0.1);
//std::cout << lightvec << std::endl;
shader->UploadActiveShaderParameter3f("frustum_corner_bl", frustum_corners[0]);
shader->UploadActiveShaderParameter3f("frustum_corner_br_delta", frustum_corners[1]-frustum_corners[0]);
shader->UploadActiveShaderParameter3f("frustum_corner_tl_delta", frustum_corners[3]-frustum_corners[0]);
}
// draw a quad
unsigned faces[2 * 3] = {
0, 1, 2,
2, 3, 0,
};
float pos[4 * 3] = {
0.0f, 0.0f, 0.0f,
1.0f, 0.0f, 0.0f,
1.0f, 1.0f, 0.0f,
0.0f, 1.0f, 0.0f,
};
// send the UV corners in UV set 0
float tc0[4 * 2] = {
0.0f, 0.0f,
maxu, 0.0f,
maxu, maxv,
0.0f, maxv,
};
// send the frustum corners in UV set 1
float tc1[4 * 3] = {
frustum_corners[0][0], frustum_corners[0][1], frustum_corners[0][2],
frustum_corners[1][0], frustum_corners[1][1], frustum_corners[1][2],
frustum_corners[2][0], frustum_corners[2][1], frustum_corners[2][2],
frustum_corners[3][0], frustum_corners[3][1], frustum_corners[3][2],
};
// fructum corners in world space in uv set 2
float tc2[4 * 3] = {
frustum_corners_w[0][0], frustum_corners_w[0][1], frustum_corners_w[0][2],
frustum_corners_w[1][0], frustum_corners_w[1][1], frustum_corners_w[1][2],
frustum_corners_w[2][0], frustum_corners_w[2][1], frustum_corners_w[2][2],
frustum_corners_w[3][0], frustum_corners_w[3][1], frustum_corners_w[3][2],
};
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, pos);
glClientActiveTexture(GL_TEXTURE0);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer(2, GL_FLOAT, 0, tc0);
glClientActiveTexture(GL_TEXTURE1);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer(3, GL_FLOAT, 0, tc1);
glClientActiveTexture(GL_TEXTURE2);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer(3, GL_FLOAT, 0, tc2);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, faces);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glClientActiveTexture(GL_TEXTURE1);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glClientActiveTexture(GL_TEXTURE0);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
CheckForOpenGLErrors("postprocess draw", error_output);
glstate.Enable(GL_DEPTH_TEST);
glstate.Disable(GL_TEXTURE_2D);
for (unsigned int i = 0; i < source_textures.size(); i++)
{
//std::cout << i << ": " << source_textures[i] << std::endl;
glActiveTexture(GL_TEXTURE0+i);
if (source_textures[i])
source_textures[i]->Deactivate();
}
glActiveTexture(GL_TEXTURE0);
CheckForOpenGLErrors("postprocess end", error_output);
}
