Implement framebuffer object

4 files changed, 177 insertions, 0 deletions

diff --git a/.clang-tidy b/.clang-tidy
index 8044098..d016a19 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -24,6 +24,7 @@ Checks:
 - -bugprone-easily-swappable-parameters
 - -portability-avoid-pragma-once
 # Various checks that interfere with C-to-C++ style code are disabled
+- -cppcoreguidelines-pro-bounds-constant-array-index
 - -cppcoreguidelines-pro-bounds-pointer-arithmetic
 - -cppcoreguidelines-pro-type-reinterpret-cast
 - -cppcoreguidelines-pro-type-vararg
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 52e6ceb..e12ed45 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,6 +9,7 @@ include(cmake/Diagnostics.cmake)
 
 add_library(drm++ SHARED
   "src/helper/ioctl.cpp"
+  "src/mode/framebuffer.cpp"
   "src/drm.cpp"
   "src/gem.cpp"
   "src/syncobject.cpp")
diff --git a/include/drm++/mode/framebuffer.hpp b/include/drm++/mode/framebuffer.hpp
new file mode 100644
index 0000000..fd904f2
--- /dev/null
+++ b/include/drm++/mode/framebuffer.hpp
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: MIT */
+
+#pragma once
+
+///
+/// * Framebuffers
+///
+/// ...
+///
+
+
+#include "../gem.hpp"
+#include "../helper/macros.hpp"
+#include "../helper/types.hpp"
+
+#include <optional>
+#include <utility>
+#include <vector>
+
+namespace drm::mode {
+
+///
+/// Framebuffer wrapping GEM objects.
+///
+/// @throws drm::ioctl::Exception on failure
+///
+class Framebuffer {
+public:
+    ///
+    /// Create a new framebuffer.
+    /// Requires DRM_CAP_ADDFB2_MODIFIERS when modifier is specified.
+    ///
+    /// Up to 4 planes can be specified for multi-planar formats.
+    ///
+    /// @param alignments Offset and pitch for each plane
+    /// @throws std::invalid_argument if planes or alignments are invalid
+    ///
+    Framebuffer(
+        int fd,
+        u32 width,
+        u32 height,
+        u32 format,
+        std::vector<ref<const gem::Object>> planes,
+        std::vector<std::pair<u32, u32>> alignments,
+        std::optional<u64> modifier,
+        bool interlaced = false
+    );
+
+    // Private access
+    GETTER(handle)
+    GETTER(width)
+    GETTER(height)
+    GETTER(format)
+    GETTER(alignments)
+    GETTER(modifier)
+    GETTER(interlaced)
+
+    // Move constructor/operator
+    Framebuffer(Framebuffer&& other) noexcept :
+            m_fd(other.m_fd), m_handle(other.m_handle),
+            m_width(other.m_width), m_height(other.m_height),
+            m_format(other.m_format), m_alignments(std::move(other.m_alignments)),
+            m_modifier(other.m_modifier), m_interlaced(other.m_interlaced) {
+        other.m_fd = -1; // invalidate other
+    }
+
+    Framebuffer& operator=(Framebuffer&& other) noexcept {
+        if (this != &other) {
+            this->destruct();
+            this->m_fd = other.m_fd;
+            this->m_handle = other.m_handle;
+            this->m_width = other.m_width;
+            this->m_height = other.m_height;
+            this->m_format = other.m_format;
+            this->m_alignments = std::move(other.m_alignments);
+            this->m_modifier = other.m_modifier;
+            this->m_interlaced = other.m_interlaced;
+            other.m_fd = -1; // invalidate other
+        }
+
+        return *this;
+    }
+
+    // Copy constructor/operator
+    NO_COPY(Framebuffer)
+
+    // Destructor
+    ~Framebuffer() noexcept {
+        this->destruct();
+    }
+private:
+    int m_fd; // indicates validity (>= 0)
+    u32 m_handle;
+
+    u32 m_width;
+    u32 m_height;
+    u32 m_format;
+    std::vector<std::pair<u32, u32>> m_alignments;
+    std::optional<u64> m_modifier;
+    bool m_interlaced;
+
+    void destruct() noexcept;
+};
+
+}
diff --git a/src/mode/framebuffer.cpp b/src/mode/framebuffer.cpp
new file mode 100644
index 0000000..46b98d1
--- /dev/null
+++ b/src/mode/framebuffer.cpp
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: MIT */
+
+#include "drm++/mode/framebuffer.hpp"
+#include "drm++/gem.hpp"
+#include "drm++/helper/ioctl.hpp"
+#include "drm++/helper/types.hpp"
+
+#include <cassert>
+#include <cstddef>
+#include <optional>
+#include <stdexcept>
+#include <utility>
+#include <vector>
+
+#include <drm.h>
+#include <drm_mode.h>
+
+using namespace drm;
+using namespace drm::mode;
+
+Framebuffer::Framebuffer(
+    int fd,
+    u32 width,
+    u32 height,
+    u32 format,
+    std::vector<ref<const gem::Object>> planes,
+    std::vector<std::pair<u32, u32>> alignments,
+    std::optional<u64> modifier,
+    bool interlaced) : m_fd(fd),
+        m_width(width), m_height(height), m_format(format),
+        m_alignments(alignments), m_modifier(modifier), m_interlaced(interlaced
+) {
+    if (planes.empty() || planes.size() > 4 || planes.size() != alignments.size()) {
+        throw std::invalid_argument("invalid number of planes");
+    }
+
+    drm_mode_fb_cmd2 args{
+        .width = width,
+        .height = height,
+        .pixel_format = format,
+        .flags = (modifier.has_value() ? DRM_MODE_FB_MODIFIERS : 0U)
+            | (interlaced ? DRM_MODE_FB_INTERLACED : 0U)
+    };
+    for (size_t i = 0; i < planes.size(); ++i) {
+        args.handles[i] = planes.at(i).get().handle();
+        args.offsets[i] = alignments.at(i).first;
+        args.pitches[i] = alignments.at(i).second;
+        args.modifier[i] = modifier.value_or(0);
+    }
+    ioctl::perform(this->m_fd, DRM_IOCTL_MODE_ADDFB2, args);
+
+    this->m_handle = args.fb_id;
+}
+
+void Framebuffer::destruct() noexcept {
+    if (this->m_fd < 0) {
+        return;
+    }
+
+    drm_mode_fb_cmd2 args{
+        .fb_id = this->m_handle
+    };
+    try {
+        ioctl::perform(this->m_fd, DRM_IOCTL_MODE_CLOSEFB, args);
+    } catch (...) {
+        assert(false && "Framebuffer close failed, memory leak likely");
+    }
+
+    this->m_fd = -1;
+}