Viewport scaling and display density independence

The view is scaled to be as large as possible, without changing the aspect, within the bounds of the window.
On "retina" displays, or other displays where window units != pixels, the view should no longer draw incorrectly.
This commit is contained in:
Kevin Hartman 2014-08-29 22:23:12 -07:00
parent 335082e74e
commit fea4505dda
7 changed files with 85 additions and 2 deletions

View file

@ -18,6 +18,10 @@ static void OnWindowSizeEvent(GLFWwindow* win, int width, int height) {
emu_window->SetClientAreaHeight(height); emu_window->SetClientAreaHeight(height);
} }
void EmuWindow_GLFW::GetFramebufferSize(int* fbWidth, int* fbHeight) {
glfwGetFramebufferSize(m_render_window, fbWidth, fbHeight);
}
/// EmuWindow_GLFW constructor /// EmuWindow_GLFW constructor
EmuWindow_GLFW::EmuWindow_GLFW() { EmuWindow_GLFW::EmuWindow_GLFW() {
// Initialize the window // Initialize the window
@ -48,6 +52,7 @@ EmuWindow_GLFW::EmuWindow_GLFW() {
//glfwSetKeyCallback(m_render_window, OnKeyEvent); //glfwSetKeyCallback(m_render_window, OnKeyEvent);
//glfwSetWindowSizeCallback(m_render_window, OnWindowSizeEvent); //glfwSetWindowSizeCallback(m_render_window, OnWindowSizeEvent);
DoneCurrent(); DoneCurrent();
} }

View file

@ -17,7 +17,7 @@ public:
void SwapBuffers(); void SwapBuffers();
/// Polls window events /// Polls window events
void PollEvents(); void PollEvents();
/// Makes the graphics context current for the caller thread /// Makes the graphics context current for the caller thread
void MakeCurrent(); void MakeCurrent();
@ -25,6 +25,9 @@ public:
/// Releases (dunno if this is the "right" word) the GLFW context from the caller thread /// Releases (dunno if this is the "right" word) the GLFW context from the caller thread
void DoneCurrent(); void DoneCurrent();
/// Gets the size of the window in pixels
void GetFramebufferSize(int* fbWidth, int* fbHeight);
GLFWwindow* m_render_window; ///< Internal GLFW render window GLFWwindow* m_render_window; ///< Internal GLFW render window
private: private:

View file

@ -179,6 +179,24 @@ void GRenderWindow::PollEvents() {
*/ */
} }
// On Qt 5.1+, this correctly gets the size of the framebuffer (pixels).
//
// Older versions get the window size (density independent pixels),
// and hence, do not support DPI scaling ("retina" displays).
// The result will be a viewport that is smaller than the extent of the window.
void GRenderWindow::GetFramebufferSize(int* fbWidth, int* fbHeight)
{
#if QT_VERSION >= QT_VERSION_CHECK(5, 1, 0)
int pixelRatio = child->QPaintDevice::devicePixelRatio();
*fbWidth = child->QPaintDevice::width() * pixelRatio;
*fbHeight = child->QPaintDevice::height() * pixelRatio;
#else
*fbWidth = child->QPaintDevice::width();
*fbHeight = child->QPaintDevice::height();
#endif
}
void GRenderWindow::BackupGeometry() void GRenderWindow::BackupGeometry()
{ {
geometry = ((QGLWidget*)this)->saveGeometry(); geometry = ((QGLWidget*)this)->saveGeometry();

View file

@ -96,6 +96,7 @@ public:
void MakeCurrent(); void MakeCurrent();
void DoneCurrent(); void DoneCurrent();
void PollEvents(); void PollEvents();
void GetFramebufferSize(int* fbWidth, int* fbHeight);
void BackupGeometry(); void BackupGeometry();
void RestoreGeometry(); void RestoreGeometry();

View file

@ -32,6 +32,9 @@ public:
/// Releases (dunno if this is the "right" word) the GLFW context from the caller thread /// Releases (dunno if this is the "right" word) the GLFW context from the caller thread
virtual void DoneCurrent() = 0; virtual void DoneCurrent() = 0;
/// Gets the size of the window in pixels
virtual void GetFramebufferSize(int* fbWidth, int* fbHeight) = 0;
Config GetConfig() const { Config GetConfig() const {
return m_config; return m_config;
} }

View file

@ -191,7 +191,8 @@ void RendererOpenGL::InitFramebuffer() {
} }
void RendererOpenGL::RenderFramebuffer() { void RendererOpenGL::RenderFramebuffer() {
glViewport(0, 0, resolution_width, resolution_height); UpdateViewportExtent();
glViewport(viewport_extent.x, viewport_extent.y, viewport_extent.width, viewport_extent.height);
glClear(GL_COLOR_BUFFER_BIT); glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(program_id); glUseProgram(program_id);
@ -243,6 +244,43 @@ void RendererOpenGL::SetWindow(EmuWindow* window) {
render_window = window; render_window = window;
} }
// TODO: This should happen on window resize callback from EmuWindow.
// It should be done when EmuWindow is refactored.
void RendererOpenGL::UpdateViewportExtent() {
int width_in_pixels;
int height_in_pixels;
render_window->GetFramebufferSize(&width_in_pixels, &height_in_pixels);
// No update needed if framebuffer size hasn't changed
if (width_in_pixels == framebuffer_size.width && height_in_pixels == framebuffer_size.height) {
return;
}
// Letterbox the emulation content into the window
framebuffer_size.width = width_in_pixels;
framebuffer_size.height = height_in_pixels;
float windowRatio = static_cast<float>(height_in_pixels) / width_in_pixels;
float emulationRatio = static_cast<float>(resolution_height) / resolution_width;
// If the window is more narrow than the emulation content, borders are applied on the
// top and bottom of the window
if (windowRatio > emulationRatio) {
viewport_extent.width = width_in_pixels;
viewport_extent.height = emulationRatio * viewport_extent.width;
viewport_extent.x = 0;
viewport_extent.y = (height_in_pixels - viewport_extent.height) / 2;
// Otherwise, borders are applied on the left and right sides of the window
} else {
viewport_extent.height = height_in_pixels;
viewport_extent.width = (1 / emulationRatio) * viewport_extent.height;
viewport_extent.x = (width_in_pixels - viewport_extent.width) / 2;
viewport_extent.y = 0;
}
}
/// Initialize the renderer /// Initialize the renderer
void RendererOpenGL::Init() { void RendererOpenGL::Init() {
render_window->MakeCurrent(); render_window->MakeCurrent();

View file

@ -52,6 +52,9 @@ private:
/// Updates the framerate /// Updates the framerate
void UpdateFramerate(); void UpdateFramerate();
/// Updates the viewport rectangle
void UpdateViewportExtent();
/// Structure used for storing information for rendering each 3DS screen /// Structure used for storing information for rendering each 3DS screen
struct ScreenInfo { struct ScreenInfo {
// Properties // Properties
@ -81,6 +84,18 @@ private:
int resolution_width; ///< Current resolution width int resolution_width; ///< Current resolution width
int resolution_height; ///< Current resolution height int resolution_height; ///< Current resolution height
struct {
int width;
int height;
} framebuffer_size; ///< Current framebuffer size
struct {
int x;
int y;
int width;
int height;
} viewport_extent; ///< Current viewport rectangle
// OpenGL global object IDs // OpenGL global object IDs
GLuint vertex_array_id; GLuint vertex_array_id;
GLuint program_id; GLuint program_id;