yuzu, video_core: Screenshot functionality

Allows capturing screenshot at the current internal resolution (native for software renderer), but a setting is available to capture it in other resolutions. The screenshot is saved to a single PNG in the current layout.

6 files changed, 95 insertions, 4 deletions

diff --git a/src/video_core/renderer_base.cpp b/src/video_core/renderer_base.cpp
index 1482cdb40..94223f45f 100644
--- a/src/video_core/renderer_base.cpp
+++ b/src/video_core/renderer_base.cpp
@@ -27,4 +27,16 @@ void RendererBase::UpdateCurrentFramebufferLayout() {
     render_window.UpdateCurrentFramebufferLayout(layout.width, layout.height);
 }
 
+void RendererBase::RequestScreenshot(void* data, std::function<void()> callback,
+                                     const Layout::FramebufferLayout& layout) {
+    if (renderer_settings.screenshot_requested) {
+        LOG_ERROR(Render, "A screenshot is already requested or in progress, ignoring the request");
+        return;
+    }
+    renderer_settings.screenshot_bits = data;
+    renderer_settings.screenshot_complete_callback = std::move(callback);
+    renderer_settings.screenshot_framebuffer_layout = layout;
+    renderer_settings.screenshot_requested = true;
+}
+
 } // namespace VideoCore
diff --git a/src/video_core/renderer_base.h b/src/video_core/renderer_base.h
index 669e26e15..1d54c3723 100644
--- a/src/video_core/renderer_base.h
+++ b/src/video_core/renderer_base.h
@@ -9,6 +9,7 @@
 #include <optional>
 
 #include "common/common_types.h"
+#include "core/frontend/emu_window.h"
 #include "video_core/gpu.h"
 #include "video_core/rasterizer_interface.h"
 
@@ -21,6 +22,12 @@ namespace VideoCore {
 struct RendererSettings {
     std::atomic_bool use_framelimiter{false};
     std::atomic_bool set_background_color{false};
+
+    // Screenshot
+    std::atomic<bool> screenshot_requested{false};
+    void* screenshot_bits;
+    std::function<void()> screenshot_complete_callback;
+    Layout::FramebufferLayout screenshot_framebuffer_layout;
 };
 
 class RendererBase : NonCopyable {
@@ -57,9 +64,29 @@ public:
         return *rasterizer;
     }
 
+    Core::Frontend::EmuWindow& GetRenderWindow() {
+        return render_window;
+    }
+
+    const Core::Frontend::EmuWindow& GetRenderWindow() const {
+        return render_window;
+    }
+
+    RendererSettings& Settings() {
+        return renderer_settings;
+    }
+
+    const RendererSettings& Settings() const {
+        return renderer_settings;
+    }
+
     /// Refreshes the settings common to all renderers
     void RefreshBaseSettings();
 
+    /// Request a screenshot of the next frame
+    void RequestScreenshot(void* data, std::function<void()> callback,
+                           const Layout::FramebufferLayout& layout);
+
 protected:
     Core::Frontend::EmuWindow& render_window; ///< Reference to the render window handle.
     std::unique_ptr<RasterizerInterface> rasterizer;
diff --git a/src/video_core/renderer_opengl/renderer_opengl.cpp b/src/video_core/renderer_opengl/renderer_opengl.cpp
index 4fd0d66c5..49a1989e4 100644
--- a/src/video_core/renderer_opengl/renderer_opengl.cpp
+++ b/src/video_core/renderer_opengl/renderer_opengl.cpp
@@ -138,7 +138,12 @@ void RendererOpenGL::SwapBuffers(
 
         // Load the framebuffer from memory, draw it to the screen, and swap buffers
         LoadFBToScreenInfo(*framebuffer);
-        DrawScreen();
+
+        if (renderer_settings.screenshot_requested)
+            CaptureScreenshot();
+
+        DrawScreen(render_window.GetFramebufferLayout());
+
         render_window.SwapBuffers();
     }
 
@@ -383,14 +388,13 @@ void RendererOpenGL::DrawScreenTriangles(const ScreenInfo& screen_info, float x,
 /**
  * Draws the emulated screens to the emulator window.
  */
-void RendererOpenGL::DrawScreen() {
+void RendererOpenGL::DrawScreen(const Layout::FramebufferLayout& layout) {
     if (renderer_settings.set_background_color) {
         // Update background color before drawing
         glClearColor(Settings::values.bg_red, Settings::values.bg_green, Settings::values.bg_blue,
                      0.0f);
     }
 
-    const auto& layout = render_window.GetFramebufferLayout();
     const auto& screen = layout.screen;
 
     glViewport(0, 0, layout.width, layout.height);
@@ -414,6 +418,37 @@ void RendererOpenGL::DrawScreen() {
 /// Updates the framerate
 void RendererOpenGL::UpdateFramerate() {}
 
+void RendererOpenGL::CaptureScreenshot() {
+    // Draw the current frame to the screenshot framebuffer
+    screenshot_framebuffer.Create();
+    GLuint old_read_fb = state.draw.read_framebuffer;
+    GLuint old_draw_fb = state.draw.draw_framebuffer;
+    state.draw.read_framebuffer = state.draw.draw_framebuffer = screenshot_framebuffer.handle;
+    state.Apply();
+
+    Layout::FramebufferLayout layout{renderer_settings.screenshot_framebuffer_layout};
+
+    GLuint renderbuffer;
+    glGenRenderbuffers(1, &renderbuffer);
+    glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB8, layout.width, layout.height);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, renderbuffer);
+
+    DrawScreen(layout);
+
+    glReadPixels(0, 0, layout.width, layout.height, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
+                 renderer_settings.screenshot_bits);
+
+    screenshot_framebuffer.Release();
+    state.draw.read_framebuffer = old_read_fb;
+    state.draw.draw_framebuffer = old_draw_fb;
+    state.Apply();
+    glDeleteRenderbuffers(1, &renderbuffer);
+
+    renderer_settings.screenshot_complete_callback();
+    renderer_settings.screenshot_requested = false;
+}
+
 static const char* GetSource(GLenum source) {
 #define RET(s)                                                                                     \
     case GL_DEBUG_SOURCE_##s:                                                                      \
diff --git a/src/video_core/renderer_opengl/renderer_opengl.h b/src/video_core/renderer_opengl/renderer_opengl.h
index c0868c0e4..067fad81b 100644
--- a/src/video_core/renderer_opengl/renderer_opengl.h
+++ b/src/video_core/renderer_opengl/renderer_opengl.h
@@ -16,6 +16,10 @@ namespace Core::Frontend {
 class EmuWindow;
 }
 
+namespace Layout {
+class FramebufferLayout;
+}
+
 namespace OpenGL {
 
 /// Structure used for storing information about the textures for the Switch screen
@@ -66,10 +70,12 @@ private:
 
     void ConfigureFramebufferTexture(TextureInfo& texture,
                                      const Tegra::FramebufferConfig& framebuffer);
-    void DrawScreen();
+    void DrawScreen(const Layout::FramebufferLayout& layout);
     void DrawScreenTriangles(const ScreenInfo& screen_info, float x, float y, float w, float h);
     void UpdateFramerate();
 
+    void CaptureScreenshot();
+
     // Loads framebuffer from emulated memory into the display information structure
     void LoadFBToScreenInfo(const Tegra::FramebufferConfig& framebuffer);
     // Fills active OpenGL texture with the given RGBA color.
@@ -82,6 +88,7 @@ private:
     OGLVertexArray vertex_array;
     OGLBuffer vertex_buffer;
     OGLProgram shader;
+    OGLFramebuffer screenshot_framebuffer;
 
     /// Display information for Switch screen
     ScreenInfo screen_info;
diff --git a/src/video_core/video_core.cpp b/src/video_core/video_core.cpp
index 07e3a7d24..f7de3471b 100644
--- a/src/video_core/video_core.cpp
+++ b/src/video_core/video_core.cpp
@@ -3,6 +3,8 @@
 // Refer to the license.txt file included.
 
 #include <memory>
+#include "core/core.h"
+#include "core/settings.h"
 #include "video_core/renderer_base.h"
 #include "video_core/renderer_opengl/renderer_opengl.h"
 #include "video_core/video_core.h"
@@ -13,4 +15,10 @@ std::unique_ptr<RendererBase> CreateRenderer(Core::Frontend::EmuWindow& emu_wind
     return std::make_unique<OpenGL::RendererOpenGL>(emu_window);
 }
 
+u16 GetResolutionScaleFactor(const RendererBase& renderer) {
+    return !Settings::values.resolution_factor
+               ? renderer.GetRenderWindow().GetFramebufferLayout().GetScalingRatio()
+               : Settings::values.resolution_factor;
+}
+
 } // namespace VideoCore
diff --git a/src/video_core/video_core.h b/src/video_core/video_core.h
index f79f85dfe..5b373bcb1 100644
--- a/src/video_core/video_core.h
+++ b/src/video_core/video_core.h
@@ -22,4 +22,6 @@ class RendererBase;
  */
 std::unique_ptr<RendererBase> CreateRenderer(Core::Frontend::EmuWindow& emu_window);
 
+u16 GetResolutionScaleFactor(const RendererBase& renderer);
+
 } // namespace VideoCore