Add methods to upload image data in Texture class

Author: kblaschke

src/libprojectM/Renderer/Texture.cpp

@@ -18,12 +18,13 @@ Texture::Texture(std::string name, const int width, const int height, const bool
     CreateNewTexture();
 }
 
-Texture::Texture(std::string name, int width, int height,
+Texture::Texture(std::string name, GLenum target, int width, int height, int depth,
                  GLint internalFormat, GLenum format, GLenum type, bool isUserTexture)
-    : m_target(GL_TEXTURE_2D)
+    : m_target(target)
     , m_name(std::move(name))
     , m_width(width)
     , m_height(height)
+    , m_depth(depth)
     , m_isUserTexture(isUserTexture)
     , m_internalFormat(internalFormat)
     , m_format(format)
@@ -43,6 +44,21 @@ Texture::Texture(std::string name, const GLuint texID, const GLenum target,
 {
 }
 
+Texture::Texture(std::string name, const void* data, GLenum target, int width, int height, int depth, GLint internalFormat, GLenum format, GLenum type, bool isUserTexture)
+    : m_target(target)
+    , m_name(std::move(name))
+    , m_width(width)
+    , m_height(height)
+    , m_depth(depth)
+    , m_isUserTexture(isUserTexture)
+    , m_internalFormat(internalFormat)
+    , m_format(format)
+    , m_type(type)
+{
+    glGenTextures(1, &m_textureId);
+    Update(data);
+}
+
 Texture::~Texture()
 {
     if (m_textureId > 0)
@@ -94,6 +110,11 @@ auto Texture::Height() const -> int
     return m_height;
 }
 
+auto Texture::Depth() const -> int
+{
+    return m_depth;
+}
+
 auto Texture::IsUserTexture() const -> bool
 {
     return m_isUserTexture;
@@ -104,11 +125,40 @@ auto Texture::Empty() const -> bool
     return m_textureId == 0;
 }
 
+void Texture::Update(const void* data) const
+{
+    glBindTexture(m_target, m_textureId);
+    switch (m_target)
+    {
+        case GL_TEXTURE_2D:
+            glTexImage2D(m_target, 0, m_internalFormat, m_width, m_height, 0, m_format, m_type, data);
+            break;
+        case GL_TEXTURE_3D:
+            glTexImage3D(m_target, 0, m_internalFormat, m_width, m_height, m_depth, 0, m_format, m_type, data);
+            break;
+        default:
+            // Unsupported, do nothing.
+            break;
+    }
+    glBindTexture(m_target, 0);
+}
+
 void Texture::CreateNewTexture()
 {
     glGenTextures(1, &m_textureId);
     glBindTexture(m_target, m_textureId);
-    glTexImage2D(m_target, 0, m_internalFormat, m_width, m_height, 0, m_format, m_type, nullptr);
+    switch (m_target)
+    {
+        case GL_TEXTURE_2D:
+            glTexImage2D(m_target, 0, m_internalFormat, m_width, m_height, 0, m_format, m_type, nullptr);
+            break;
+        case GL_TEXTURE_3D:
+            glTexImage3D(m_target, 0, m_internalFormat, m_width, m_height, m_depth, 0, m_format, m_type, nullptr);
+            break;
+        default:
+            // Unsupported, do nothing.
+            break;
+    }
     glBindTexture(m_target, 0);
 }
 

src/libprojectM/Renderer/Texture.hpp

@@ -39,11 +39,16 @@ class Texture
     /**
      * @brief Constructor. Allocates a new, empty texture with the given size and format.
      * @param name Optional name of the texture for referencing in Milkdrop shaders.
+     * @param target The texture target, either TEXTURE_2D or TEXTURE_3D.
      * @param width Width in pixels.
      * @param height Height in pixels.
+     * @param depth Depth in pixels (for 3D textures).
+     * @param internalFormat OpenGL internal texture format.
+     * @param format OpenGL texture format.
+     * @param type Storage type for each color channel.
      * @param isUserTexture true if the texture is an externally-loaded image, false if it's an internal texture.
      */
-    explicit Texture(std::string name, int width, int height,
+    explicit Texture(std::string name, GLenum target, int width, int height, int depth,
                      GLint internalFormat, GLenum format, GLenum type, bool isUserTexture);
 
     /**
@@ -60,6 +65,22 @@ class Texture
                      int width, int height,
                      bool isUserTexture);
 
+    /**
+     * @brief Constructor. Creates a new texture from image data with the given size and format.
+     * @param name Optional name of the texture for referencing in Milkdrop shaders.
+     * @param data The texture data to upload.
+     * @param target The texture target, either TEXTURE_2D or TEXTURE_3D.
+     * @param width Width in pixels.
+     * @param height Height in pixels.
+     * @param depth Depth in pixels (for 3D textures).
+     * @param internalFormat OpenGL internal texture format.
+     * @param format OpenGL texture format.
+     * @param type Storage type for each color channel.
+     * @param isUserTexture true if the texture is an externally-loaded image, false if it's an internal texture.
+     */
+    explicit Texture(std::string name, const void* data, GLenum target, int width, int height, int depth,
+                     GLint internalFormat, GLenum format, GLenum type, bool isUserTexture);
+
     Texture(Texture&& other) = default;
     auto operator=(Texture&& other) -> Texture& = default;
 
@@ -109,6 +130,12 @@ class Texture
      */
     auto Height() const -> int;
 
+    /**
+     * @brief Returns the depth of the texture image in pixels.
+     * @return The depth of the texture image in pixels.
+     */
+    auto Depth() const -> int;
+
     /**
      * @brief Returns if the texture is user-defined, e.g. loaded from an image.
      * @return true if the texture is a user texture, false if it's an internally generated texture.
@@ -121,6 +148,13 @@ class Texture
      */
     auto Empty() const -> bool;
 
+    /**
+     * @brief Uploads new image data for the texture.
+     * @note Automatically binds and unbinds the texture.
+     * @param data The new texture image data. Must match the size and format used to create the texture.
+     */
+    void Update(const void* data) const;
+
 private:
     /**
      * @brief Creates a new, blank texture with the given size.
@@ -133,6 +167,7 @@ class Texture
     std::string m_name;          //!< The texture name for identifying it in shaders.
     int m_width{0};              //!< Texture width in pixels.
     int m_height{0};             //!< Texture height in pixels.
+    int m_depth{0};              //!< Texture depth in pixels. Only used for 3D textures.
     bool m_isUserTexture{false}; //!< true if it's a user texture, false if an internal one.
 
     GLint m_internalFormat{}; //!< OpenGL internal format, e.g. GL_RGBA8