cs381/assets/skybox.cpp

168 lines
7.2 KiB
C++

/*******************************************************************************************
*
* raylib [models] example - Skybox loading and drawing
*
* Example originally created with raylib 1.8, last time updated with raylib 4.0
*
* Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
* BSD-like license that allows static linking with closed source software
*
* Copyright (c) 2017-2023 Ramon Santamaria (@raysan5)
*
********************************************************************************************/
#include "skybox.hpp"
#include <iostream>
#include "rlgl.h"
namespace cs381 {
SkyBox& SkyBox::Init() {
// Load skybox model
cube = raylib::Mesh::Cube(1.0f, 1.0f, 1.0f).LoadModelFrom();
// Load skybox shader and set required locations
// NOTE: Some locations are automatically set at shader loading
shader = raylib::Shader::LoadFromMemory(vertexShader, fragmentShader);
cube.materials[0].shader = shader;
shader.SetValue("environmentMap", (int)MATERIAL_MAP_CUBEMAP, SHADER_UNIFORM_INT);
return *this;
}
SkyBox& SkyBox::Load(const std::string_view filename, bool isEnviornment/* = false*/) {
if(shader.id == 0) Init();
shader.SetValue("doGamma", int(isEnviornment ? 1 : 0), SHADER_UNIFORM_INT);
shader.SetValue("vflipped", int(isEnviornment ? 1 : 0), SHADER_UNIFORM_INT);
if(isEnviornment) {
if(cubemapShader.id == 0){
cubemapShader = raylib::Shader::LoadFromMemory(cubemapVertexShader, cubemapFragmentShader);
cubemapShader.SetValue("equirectangularMap", int(0), SHADER_UNIFORM_INT);
}
// Load HDR panorama (sphere) texture
texture.Load(filename);
// Make sure that things aren't sampled in a pixelated manor!
texture.SetFilter(TEXTURE_FILTER_BILINEAR);
// Generate cubemap (texture with 6 quads-cube-mapping) from panorama HDR texture
// NOTE 1: New texture is generated rendering to texture, shader calculates the sphere->cube coordinates mapping
// NOTE 2: It seems on some Android devices WebGL, fbo does not properly support a FLOAT-based attachment,
// despite texture can be successfully created.. so using PIXELFORMAT_UNCOMPRESSED_R8G8B8A8 instead of PIXELFORMAT_UNCOMPRESSED_R32G32B32A32
cube.materials[0].maps[MATERIAL_MAP_CUBEMAP].texture = GenTextureCubemap(cubemapShader, texture, 1024, PIXELFORMAT_UNCOMPRESSED_R8G8B8A8);
} else {
raylib::Image img(filename);
texture.Load(img, CUBEMAP_LAYOUT_AUTO_DETECT);
// Make sure that things aren't sampled in a pixelated manor!
texture.SetFilter(TEXTURE_FILTER_BILINEAR);
cube.materials[0].maps[MATERIAL_MAP_CUBEMAP].texture = texture; // CUBEMAP_LAYOUT_PANORAMA
}
return *this;
}
SkyBox& SkyBox::Draw() {
// We are inside the cube, we need to disable backface culling!
rlDisableBackfaceCulling();
rlDisableDepthMask();
cube.Draw({});
rlEnableBackfaceCulling();
rlEnableDepthMask();
return *this;
}
// Generate cubemap texture from HDR texture
TextureCubemap SkyBox::GenTextureCubemap(Shader shader, Texture2D panorama, int size, int format) {
TextureCubemap cubemap = { 0 };
rlDisableBackfaceCulling(); // Disable backface culling to render inside the cube
// STEP 1: Setup framebuffer
//------------------------------------------------------------------------------------------
unsigned int rbo = rlLoadTextureDepth(size, size, true);
cubemap.id = rlLoadTextureCubemap(0, size, format, 1);
// unsigned int fbo = rlLoadFramebuffer(size, size);
unsigned int fbo = rlLoadFramebuffer();
rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER, 0);
rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X, 0);
// Check if framebuffer is complete with attachments (valid)
if (rlFramebufferComplete(fbo)) TraceLog(LOG_INFO, "FBO: [ID %i] Framebuffer object created successfully", fbo);
//------------------------------------------------------------------------------------------
// STEP 2: Draw to framebuffer
//------------------------------------------------------------------------------------------
// NOTE: Shader is used to convert HDR equirectangular environment map to cubemap equivalent (6 faces)
rlEnableShader(shader.id);
// Define projection matrix and send it to shader
Matrix matFboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_PROJECTION], matFboProjection);
// Define view matrix for every side of the cubemap
Matrix fboViews[6] = {
MatrixLookAt(Vector3{ 0.0f, 0.0f, 0.0f }, Vector3{ 1.0f, 0.0f, 0.0f }, Vector3{ 0.0f, -1.0f, 0.0f }),
MatrixLookAt(Vector3{ 0.0f, 0.0f, 0.0f }, Vector3{ -1.0f, 0.0f, 0.0f }, Vector3{ 0.0f, -1.0f, 0.0f }),
MatrixLookAt(Vector3{ 0.0f, 0.0f, 0.0f }, Vector3{ 0.0f, 1.0f, 0.0f }, Vector3{ 0.0f, 0.0f, 1.0f }),
MatrixLookAt(Vector3{ 0.0f, 0.0f, 0.0f }, Vector3{ 0.0f, -1.0f, 0.0f }, Vector3{ 0.0f, 0.0f, -1.0f }),
MatrixLookAt(Vector3{ 0.0f, 0.0f, 0.0f }, Vector3{ 0.0f, 0.0f, 1.0f }, Vector3{ 0.0f, -1.0f, 0.0f }),
MatrixLookAt(Vector3{ 0.0f, 0.0f, 0.0f }, Vector3{ 0.0f, 0.0f, -1.0f }, Vector3{ 0.0f, -1.0f, 0.0f })
};
rlViewport(0, 0, size, size); // Set viewport to current fbo dimensions
// Activate and enable texture for drawing to cubemap faces
rlActiveTextureSlot(0);
rlEnableTexture(panorama.id);
for (int i = 0; i < 6; i++) {
// Set the view matrix for the current cube face
rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_VIEW], fboViews[i]);
// Select the current cubemap face attachment for the fbo
// WARNING: This function by default enables->attach->disables fbo!!!
rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i, 0);
rlEnableFramebuffer(fbo);
// Load and draw a cube, it uses the current enabled texture
rlClearScreenBuffers();
rlLoadDrawCube();
// ALTERNATIVE: Try to use internal batch system to draw the cube instead of rlLoadDrawCube
// for some reason this method does not work, maybe due to cube triangles definition? normals pointing out?
// TODO: Investigate this issue...
//rlSetTexture(panorama.id); // WARNING: It must be called after enabling current framebuffer if using internal batch system!
//rlClearScreenBuffers();
//DrawCubeV(Vector3Zero(), Vector3One(), WHITE);
//rlDrawRenderBatchActive();
}
//------------------------------------------------------------------------------------------
// STEP 3: Unload framebuffer and reset state
//------------------------------------------------------------------------------------------
rlDisableShader(); // Unbind shader
rlDisableTexture(); // Unbind texture
rlDisableFramebuffer(); // Unbind framebuffer
rlUnloadFramebuffer(fbo); // Unload framebuffer (and automatically attached depth texture/renderbuffer)
// Reset viewport dimensions to default
rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
rlEnableBackfaceCulling();
//------------------------------------------------------------------------------------------
cubemap.width = size;
cubemap.height = size;
cubemap.mipmaps = 1;
cubemap.format = format;
return cubemap;
}
raylib::Shader SkyBox::cubemapShader(0);
}