[add]: add HDRI

4 files changed, 212 insertions, 2 deletions

diff --git a/src/Platform/OpenGL/OpenGLFramebuffer.cpp b/src/Platform/OpenGL/OpenGLFramebuffer.cpp
index 523d748..3bb62f6 100644
--- a/src/Platform/OpenGL/OpenGLFramebuffer.cpp
+++ b/src/Platform/OpenGL/OpenGLFramebuffer.cpp
@@ -123,7 +123,6 @@ namespace Donut
 
         bool multisample = m_Specification.Samples > 1;
 
-        // Attachments
         if (m_ColorAttachmentSpecifications.size())
         {
             m_ColorAttachments.resize(m_ColorAttachmentSpecifications.size());
diff --git a/src/Platform/OpenGL/OpenGLShader.h b/src/Platform/OpenGL/OpenGLShader.h
index e9a7dc2..99a150b 100644
--- a/src/Platform/OpenGL/OpenGLShader.h
+++ b/src/Platform/OpenGL/OpenGLShader.h
@@ -32,6 +32,7 @@ namespace Donut
         virtual void MemoryBarrier(uint32_t barriers)                     override;
 
         virtual const std::string& GetName() const override { return m_Name; }
+        virtual uint32_t GetRendererID() const override { return m_RendererID; }
 
         void UploadUniformInt(     const std::string& name, int value);
         void UploadUniformIntArray(const std::string& name, int* values, uint32_t count);
diff --git a/src/Platform/OpenGL/OpenGLTexture.cpp b/src/Platform/OpenGL/OpenGLTexture.cpp
index e12dea4..d9033dc 100644
--- a/src/Platform/OpenGL/OpenGLTexture.cpp
+++ b/src/Platform/OpenGL/OpenGLTexture.cpp
@@ -1,5 +1,13 @@
 #include "OpenGLTexture.h"
 
+#include "Rendering/Shader.h"
+
+#define STB_IMAGE_IMPLEMENTATION
+#include "stb_image.h"
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+
 namespace Donut
 {
     OpenGLTexture2D::OpenGLTexture2D(uint32_t width, uint32_t height)
@@ -18,7 +26,6 @@ namespace Donut
         glTextureParameteri(m_RendererID, GL_TEXTURE_WRAP_T, GL_REPEAT);
     }
 
-    // TODO(Hachem): Texture Loading
     OpenGLTexture2D::OpenGLTexture2D(const std::string& path)
         : m_Path(path)
     {
@@ -69,4 +76,176 @@ namespace Donut
         GLenum access = readOnly ? GL_READ_ONLY : GL_WRITE_ONLY;
         glBindImageTexture(slot, m_RendererID, 0, GL_FALSE, 0, access, m_InternalFormat);
     }
+
+    OpenGLCubemapTexture::OpenGLCubemapTexture(uint32_t width, uint32_t height)
+        : m_Width(width), m_Height(height)
+    {
+        m_InternalFormat = GL_RGB16F;
+        m_DataFormat     = GL_RGB;
+
+        glCreateTextures(GL_TEXTURE_CUBE_MAP, 1, &m_RendererID);
+        glTextureStorage2D(m_RendererID, 1, m_InternalFormat, m_Width, m_Height);
+
+        glTextureParameteri(m_RendererID, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTextureParameteri(m_RendererID, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+        glTextureParameteri(m_RendererID, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+        glTextureParameteri(m_RendererID, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+        glTextureParameteri(m_RendererID, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+    }
+
+    OpenGLCubemapTexture::OpenGLCubemapTexture(const std::string& path)
+        : m_Path(path)
+    {
+        m_Width          = 1024;
+        m_Height         = 1024;
+        m_InternalFormat = GL_RGB16F;
+        m_DataFormat     = GL_RGB;
+
+        glCreateTextures(GL_TEXTURE_CUBE_MAP, 1, &m_RendererID);
+        glTextureStorage2D(m_RendererID, 1, m_InternalFormat, m_Width, m_Height);
+
+        glTextureParameteri(m_RendererID, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTextureParameteri(m_RendererID, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+        glTextureParameteri(m_RendererID, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+        glTextureParameteri(m_RendererID, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+        glTextureParameteri(m_RendererID, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+
+        LoadHDRI(path);
+    }
+
+    OpenGLCubemapTexture::~OpenGLCubemapTexture()
+    {
+        glDeleteTextures(1, &m_RendererID);
+    }
+
+    void OpenGLCubemapTexture::LoadHDRI(const std::string& path)
+    {
+        stbi_set_flip_vertically_on_load(true);
+        int width, height, channels;
+        float* hdrData = stbi_loadf(path.c_str(), &width, &height, &channels, 3);
+        
+        if (!hdrData)
+        {
+            DONUT_ERROR("Failed to load HDRI: {}", path);
+            float defaultSky[6 * 4] = 
+            {
+                0.5f, 0.7f, 1.0f, 1.0f,  // Right
+                0.5f, 0.7f, 1.0f, 1.0f,  // Left
+                0.5f, 0.7f, 1.0f, 1.0f,  // Top
+                0.5f, 0.7f, 1.0f, 1.0f,  // Bottom
+                0.5f, 0.7f, 1.0f, 1.0f,  // Front
+                0.5f, 0.7f, 1.0f, 1.0f   // Back
+            };
+            
+            for (int i = 0; i < 6; ++i)
+                glTextureSubImage3D(m_RendererID, 0, 0, 0, i, 1, 1, 1, GL_RGBA, GL_FLOAT, &defaultSky[i * 4]);
+            return;
+        }
+
+        ConvertEquirectangularToCubemap(hdrData, width, height);
+        stbi_image_free(hdrData);
+        
+        DONUT_INFO("Successfully loaded HDRI: {} ({}x{})", path, width, height);
+    }
+
+    void OpenGLCubemapTexture::ConvertEquirectangularToCubemap(float* hdrData, int width, int height)
+    {
+        uint32_t captureFBO, captureRBO;
+        glGenFramebuffers(1, &captureFBO);
+        glGenRenderbuffers(1, &captureRBO);
+
+        glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+        glBindRenderbuffer(GL_RENDERBUFFER, captureRBO);
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, m_Width, m_Height);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, captureRBO);
+
+        uint32_t hdrTexture;
+        glGenTextures(1, &hdrTexture);
+        glBindTexture(GL_TEXTURE_2D, hdrTexture);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, width, height, 0, GL_RGB, GL_FLOAT, hdrData);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        auto equirectShader = Shader::Create("Assets/Shaders/EquirectToCubemap.glsl");
+        if (!equirectShader)
+        {
+            DONUT_ERROR("Failed to create equirectangular to cubemap shader");
+            return;
+        }
+        
+        uint32_t shaderProgram = equirectShader->GetRendererID();
+
+        float vertices[] = 
+        {
+            -1.0f,  1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f,  1.0f, -1.0f, -1.0f,  1.0f, -1.0f,
+            -1.0f, -1.0f,  1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f,  1.0f, -1.0f, -1.0f,  1.0f,
+             1.0f, -1.0f, -1.0f,  1.0f, -1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f, -1.0f,  1.0f, -1.0f, -1.0f,
+            -1.0f, -1.0f,  1.0f, -1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f,
+            -1.0f,  1.0f, -1.0f,  1.0f,  1.0f, -1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f,  1.0f, -1.0f,  1.0f,  1.0f, -1.0f,  1.0f, -1.0f,
+            -1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f,  1.0f, -1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f
+        };
+
+        uint32_t cubeVAO, cubeVBO;
+        glGenVertexArrays(1, &cubeVAO);
+        glGenBuffers(1, &cubeVBO);
+        glBindVertexArray(cubeVAO);
+        glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+        glEnableVertexAttribArray(0);
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+
+        glm::mat4 captureProjection = glm::perspective(glm::radians(90.0f), 1.0f, 0.1f, 10.0f);
+        glm::mat4 captureViews[] = 
+        {
+            glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3( 1.0f,  0.0f,  0.0f), glm::vec3(0.0f, -1.0f,  0.0f)),
+            glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(-1.0f,  0.0f,  0.0f), glm::vec3(0.0f, -1.0f,  0.0f)),
+            glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3( 0.0f,  1.0f,  0.0f), glm::vec3(0.0f,  0.0f,  1.0f)),
+            glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3( 0.0f, -1.0f,  0.0f), glm::vec3(0.0f,  0.0f, -1.0f)),
+            glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3( 0.0f,  0.0f,  1.0f), glm::vec3(0.0f, -1.0f,  0.0f)),
+            glm::lookAt(glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3( 0.0f,  0.0f, -1.0f), glm::vec3(0.0f, -1.0f,  0.0f))
+        };
+
+        glUseProgram(shaderProgram);
+        glUniform1i(glGetUniformLocation(shaderProgram, "equirectangularMap"), 0);
+        glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "projection"), 1, GL_FALSE, &captureProjection[0][0]);
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, hdrTexture);
+
+        glViewport(0, 0, m_Width, m_Height);
+        glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+        for (unsigned int i = 0; i < 6; ++i)
+        {
+            glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "view"), 1, GL_FALSE, &captureViews[i][0][0]);
+            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, m_RendererID, 0);
+            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+            glBindVertexArray(cubeVAO);
+            glDrawArrays(GL_TRIANGLES, 0, 36);
+        }
+        glBindVertexArray(0);
+
+        glDeleteVertexArrays(1, &cubeVAO);
+        glDeleteBuffers(1, &cubeVBO);
+        glDeleteProgram(shaderProgram);
+        glDeleteTextures(1, &hdrTexture);
+        glDeleteFramebuffers(1, &captureFBO);
+        glDeleteRenderbuffers(1, &captureRBO);
+    }
+
+    void OpenGLCubemapTexture::SetData(void* data, uint32_t size)
+    {
+        DONUT_WARN("SetData not implemented for cubemaps");
+    }
+
+    void OpenGLCubemapTexture::Bind(uint32_t slot) const
+    {
+        glBindTextureUnit(slot, m_RendererID);
+    }
+
+    void OpenGLCubemapTexture::BindAsImage(uint32_t slot, bool readOnly) const
+    {
+        GLenum access = readOnly ? GL_READ_ONLY : GL_WRITE_ONLY;
+        glBindImageTexture(slot, m_RendererID, 0, GL_TRUE, 0, access, m_InternalFormat);
+    }
 };
\ No newline at end of file
diff --git a/src/Platform/OpenGL/OpenGLTexture.h b/src/Platform/OpenGL/OpenGLTexture.h
index 1c3cb05..220df09 100644
--- a/src/Platform/OpenGL/OpenGLTexture.h
+++ b/src/Platform/OpenGL/OpenGLTexture.h
@@ -34,4 +34,35 @@ namespace Donut
         uint32_t    m_RendererID;
         GLenum      m_InternalFormat, m_DataFormat;
     };
+
+    class OpenGLCubemapTexture 
+        : public CubemapTexture
+    {
+    public:
+        OpenGLCubemapTexture(uint32_t width, uint32_t height);
+        OpenGLCubemapTexture(const std::string& path);
+        virtual ~OpenGLCubemapTexture();
+
+        virtual uint32_t GetWidth()      const override { return m_Width; }
+        virtual uint32_t GetHeight()     const override { return m_Height; }
+        virtual uint32_t GetRendererID() const override { return m_RendererID; }
+
+        virtual void SetData(void* data, uint32_t size)                          override;
+        virtual void Bind(uint32_t slot = 0)                               const override;
+        virtual void BindAsImage(uint32_t slot = 0, bool readOnly = false) const override;
+
+        virtual bool operator==(const Texture& other) const override
+        {
+            return m_RendererID == other.GetRendererID();
+        }
+
+    private:
+        void LoadHDRI(const std::string& path);
+        void ConvertEquirectangularToCubemap(float* hdrData, int width, int height);
+
+        std::string m_Path;
+        uint32_t    m_Width, m_Height;
+        uint32_t    m_RendererID;
+        GLenum      m_InternalFormat, m_DataFormat;
+    };
 }