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#include "billboardPainter.h"
#include "gfx/models/mesh.h"
#include "glArrays.h"
#include "gl_traits.h"
#include "gldebug.h"
#include "maths.h"
#include <gfx/gl/shaders/billboardPainter-frag.h>
#include <gfx/gl/shaders/billboardPainter-geom.h>
#include <gfx/gl/shaders/billboardPainter-vert.h>
#include <stdexcept>
const auto VIEWS = []<GLint... Ep>(std::integer_sequence<GLint, Ep...>) {
constexpr float STEP = two_pi / BillboardPainter::VIEW_ANGLES<decltype(two_pi)>;
return std::array {rotate_yaw<4>(Ep * STEP)...};
}(std::make_integer_sequence<GLint, BillboardPainter::VIEW_ANGLES<GLint>>());
BillboardPainter::BillboardPainter() :
program {billboardPainter_vert, billboardPainter_geom, billboardPainter_frag}, view {}
{
glDebugScope _ {fbo};
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
static constexpr std::array<GLenum, 2> ATTACHMENTS {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1};
glDrawBuffers(ATTACHMENTS.size(), ATTACHMENTS.data());
glReadBuffer(GL_NONE);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glUseProgram(program);
glUniform(viewLoc, std::span<const glm::mat4> {VIEWS});
}
void
BillboardPainter::setView(const glm::mat4 & newView)
{
view = newView;
}
glTextures<3>
BillboardPainter::createBillBoardTextures(GLsizei width, GLsizei height)
{
glDebugScope _ {0};
glTextures<3> textures;
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
const auto configuregdata = [width, height](const auto & texture, const GLint iformat, const GLenum format) {
texture.bind(GL_TEXTURE_2D_ARRAY);
glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, iformat, width, height, VIEW_ANGLES<GLint>, 0, format, GL_BYTE, nullptr);
};
configuregdata(textures[0], GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT);
configuregdata(textures[1], GL_RGB8_SNORM, GL_RGB);
configuregdata(textures[2], GL_RGB5_A1, GL_RGBA);
return textures;
}
void
BillboardPainter::renderBillBoard(
const glTextures<3> & billboard, const MeshBase & mesh, const Texture::AnyPtr texture) const
{
glDebugScope _ {fbo};
glEnable(GL_BLEND);
glEnable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glCullFace(GL_BACK);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glClearColor(0, 0, 0, 0);
glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, billboard[0], 0);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, billboard[1], 0);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, billboard[2], 0);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
throw std::runtime_error("Billboard framebuffer not complete!");
}
if (texture) {
texture->bind();
}
glUseProgram(program);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
const TextureDimensions billboardSize = billboard[0].getSize();
glViewport(0, 0, billboardSize.x, billboardSize.y);
const auto & centre = mesh.getDimensions().centre;
const auto & size = mesh.getDimensions().size;
glUniform(viewProjectionLoc,
std::span<const glm::mat4> {VIEWS *
[extentsMat = glm::translate(glm::ortho(-size, size, -size, size, -size, size), -centre), this](
const auto & view) {
return this->view * view * extentsMat;
}});
mesh.Draw();
}
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