[retro-gtk] Add RetroPixdata

[Adrien Plazas <aplazas src gnome org>]

commit de0a7789e9a7de0d405edc366145e94b9332d14b
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Thu Oct 12 15:52:42 2017 +0200

    Add RetroPixdata
    
    This will be used in the next commit to simplify handling of the core's
    video output.

 retro-gtk/Makefile.am             |    3 +
 retro-gtk/retro-pixdata-private.h |   36 ++++
 retro-gtk/retro-pixdata.c         |  320 +++++++++++++++++++++++++++++++++++++
 retro-gtk/retro-pixdata.h         |   30 ++++
 4 files changed, 389 insertions(+), 0 deletions(-)
---
diff --git a/retro-gtk/Makefile.am b/retro-gtk/Makefile.am
index 5a8116b..4f91e5d 100644
--- a/retro-gtk/Makefile.am
+++ b/retro-gtk/Makefile.am
@@ -45,6 +45,7 @@ retro_gtk_public_h_sources = \
        retro-module-iterator.h \
        retro-module-query.h \
        retro-mouse-id.h \
+       retro-pixdata.h \
        retro-pixel-format.h \
        retro-pointer-id.h \
        retro-rumble-effect.h \
@@ -65,6 +66,7 @@ retro_gtk_private_h_sources = \
        retro-option.h \
        retro-options.h \
        retro-pa-player.h \
+       retro-pixdata-private.h \
        retro-rotation.h \
        retro-system-av-info.h \
        retro-system-info.h \
@@ -96,6 +98,7 @@ libretro_gtk_la_SOURCES = \
        retro-option.c \
        retro-options.c \
        retro-pa-player.c \
+       retro-pixdata.c \
        retro-pixel-format.c \
        retro-pointer-id.c \
        retro-rumble-effect.c \
diff --git a/retro-gtk/retro-pixdata-private.h b/retro-gtk/retro-pixdata-private.h
new file mode 100644
index 0000000..01fe4b7
--- /dev/null
+++ b/retro-gtk/retro-pixdata-private.h
@@ -0,0 +1,36 @@
+// This file is part of retro-gtk. License: GPL-3.0+.
+
+#ifndef RETRO_PIXDATA_PRIVATE_H
+#define RETRO_PIXDATA_PRIVATE_H
+
+#if !defined(__RETRO_GTK_INSIDE__) && !defined(RETRO_GTK_COMPILATION)
+# error "Only <retro-gtk.h> can be included directly."
+#endif
+
+#include "retro-pixdata.h"
+
+#include "retro-pixel-format.h"
+
+G_BEGIN_DECLS
+
+struct _RetroPixdata
+{
+  guint8 *data;
+  RetroPixelFormat pixel_format;
+  gsize rowstride;
+  gsize width;
+  gsize height;
+  gfloat aspect_ratio;
+};
+
+void retro_pixdata_init (RetroPixdata     *self,
+                         gconstpointer     data,
+                         RetroPixelFormat  pixel_format,
+                         gsize             rowstride,
+                         gsize             width,
+                         gsize             height,
+                         gfloat            aspect_ratio);
+
+G_END_DECLS
+
+#endif /* RETRO_PIXDATA_PRIVATE_H */
diff --git a/retro-gtk/retro-pixdata.c b/retro-gtk/retro-pixdata.c
new file mode 100644
index 0000000..244fe85
--- /dev/null
+++ b/retro-gtk/retro-pixdata.c
@@ -0,0 +1,320 @@
+// This file is part of retro-gtk. License: GPL-3.0+.
+
+#include "retro-pixdata-private.h"
+
+G_DEFINE_BOXED_TYPE (RetroPixdata, retro_pixdata, retro_pixdata_copy, retro_pixdata_free)
+
+/*
+ * Because gdk-pixbuf saves dpi as integer we have to multiply it by big enough
+ * number to represent aspect ratio precisely.
+ */
+#define RETRO_CAIRO_DISPLAY_Y_DPI (1000000.0f)
+
+/* Private */
+
+typedef struct {
+  guint16 b: 5;
+  guint16 g: 5;
+  guint16 r: 5;
+  guint16 x: 1;
+} xrgb1555;
+
+typedef struct {
+  guint32 b: 8;
+  guint32 g: 8;
+  guint32 r: 8;
+  guint32 x: 8;
+} xrgb8888;
+
+typedef struct {
+  guint16 b: 5;
+  guint16 g: 6;
+  guint16 r: 5;
+} rgb565;
+
+typedef struct {
+  guint32 a: 8;
+  guint32 b: 8;
+  guint32 g: 8;
+  guint32 r: 8;
+} rgba8888;
+
+typedef rgba8888 (*GetRGBA8888) (gconstpointer pixel);
+
+static rgba8888
+rgba8888_from_xrgb1555 (gconstpointer data)
+{
+  xrgb1555 pixel = *(const xrgb1555 *) data;
+
+  return (rgba8888) {
+    pixel.r << 3 | pixel.r >> 2,
+    pixel.g << 3 | pixel.g >> 2,
+    pixel.b << 3 | pixel.b >> 2,
+    0xff,
+  };
+}
+
+static rgba8888
+rgba8888_from_xrgb8888 (gconstpointer data)
+{
+  xrgb8888 pixel = *(const xrgb8888 *) data;
+
+  return (rgba8888) {
+    pixel.r,
+    pixel.g,
+    pixel.b,
+    0xff,
+  };
+}
+
+static rgba8888
+rgba8888_from_rgb565 (gconstpointer data)
+{
+  rgb565 pixel = *(const rgb565 *) data;
+
+  return (rgba8888) {
+    pixel.r << 3 | pixel.r >> 2,
+    pixel.g << 2 | pixel.g >> 4,
+    pixel.b << 3 | pixel.b >> 2,
+    0xff,
+  };
+}
+
+static gboolean
+get_interface_for_pixel_format (gint         pixel_format,
+                                GetRGBA8888 *get_pixel,
+                                gsize       *pixel_size)
+{
+  switch (pixel_format) {
+  case RETRO_PIXEL_FORMAT_XRGB1555:
+    *get_pixel = rgba8888_from_xrgb1555;
+    *pixel_size = sizeof (xrgb1555);
+
+    return TRUE;
+  case RETRO_PIXEL_FORMAT_XRGB8888:
+    *get_pixel = rgba8888_from_xrgb8888;
+    *pixel_size = sizeof (rgba8888);
+
+    return TRUE;
+  case RETRO_PIXEL_FORMAT_RGB565:
+    *get_pixel = rgba8888_from_rgb565;
+    *pixel_size = sizeof (rgb565);
+
+    return TRUE;
+  default:
+    return FALSE;
+  }
+}
+
+/*
+ * The destination buffer must be at least `height * width * sizeof (rgba8888)`
+ * bytes long.
+ */
+static void
+rgba8888_from_video (gconstpointer  src,
+                     rgba8888      *dst,
+                     size_t         pixel_size,
+                     guint          width,
+                     guint          height,
+                     gsize          pitch,
+                     GetRGBA8888    get_pixel)
+{
+  gsize row, src_row, dst_row, col, src_col;
+
+  for (row = 0 ; row < height ; row++) {
+    src_row = row * pitch;
+    dst_row = row * width;
+
+    for (col = 0 ; col < width ; col++) {
+      src_col = col * pixel_size;
+
+      dst[dst_row + col] = get_pixel (src_row + src_col + src);
+    }
+  }
+}
+
+static void
+pixels_free (guchar   *pixels,
+             gpointer  data)
+{
+  g_free (pixels);
+}
+
+/**
+ * retro_pixdata_new:
+ * @data: the video data
+ * @width: the width
+ * @height: the height
+ * @pitch: the distance in bytes between rows
+ * @pixel_format: the pixel format
+ * @aspect_ratio: the aspect ratio to render the video
+ *
+ * Creates a new #RetroPixdata.
+ *
+ * Returns: (transfer full): a new #RetroPixdata, use retro_pixdata_free() to
+ * free it
+ */
+static RetroPixdata *
+retro_pixdata_new (gconstpointer    data,
+                   RetroPixelFormat pixel_format,
+                   gsize            rowstride,
+                   gsize            width,
+                   gsize            height,
+                   gfloat           aspect_ratio)
+{
+  RetroPixdata *self;
+
+  g_return_val_if_fail (data != NULL, NULL);
+  g_return_val_if_fail (rowstride != 0, NULL);
+  g_return_val_if_fail (width != 0, NULL);
+  g_return_val_if_fail (height != 0, NULL);
+  g_return_val_if_fail (aspect_ratio > 0.f, NULL);
+
+  self = g_slice_new0 (RetroPixdata);
+  self->data = g_memdup (data, rowstride * height);
+  self->pixel_format = pixel_format;
+  self->rowstride = rowstride;
+  self->width = width;
+  self->height = height;
+  self->aspect_ratio = aspect_ratio;
+
+  return self;
+}
+
+/* Public */
+
+/**
+ * retro_pixdata_init:
+ * @self: a #RetroPixdata
+ * @data: the video data
+ * @width: the width
+ * @height: the height
+ * @pitch: the distance in bytes between rows
+ * @pixel_format: the pixel format
+ * @aspect_ratio: the aspect ratio to render the video
+ *
+ * Initializes @self with the given parameters.
+ */
+void
+retro_pixdata_init (RetroPixdata     *self,
+                    gconstpointer     data,
+                    RetroPixelFormat  pixel_format,
+                    gsize             rowstride,
+                    gsize             width,
+                    gsize             height,
+                    gfloat            aspect_ratio)
+{
+  g_return_if_fail (self != NULL);
+  g_return_if_fail (data != NULL);
+  g_return_if_fail (rowstride != 0);
+  g_return_if_fail (width != 0);
+  g_return_if_fail (height != 0);
+  g_return_if_fail (aspect_ratio > 0.f);
+
+  self->data = (guint8 *) data;
+  self->pixel_format = pixel_format;
+  self->rowstride = rowstride;
+  self->width = width;
+  self->height = height;
+  self->aspect_ratio = aspect_ratio;
+}
+
+/**
+ * retro_pixdata_copy:
+ * @self: a #RetroPixdata
+ *
+ * Copies @self into a new #RetroPixdata.
+ *
+ * Returns: (transfer full): a new #RetroPixdata, use retro_pixdata_free() to
+ * free it
+ */
+RetroPixdata *
+retro_pixdata_copy (RetroPixdata *self)
+{
+  g_return_val_if_fail (self != NULL, NULL);
+
+  return retro_pixdata_new (self->data, self->pixel_format,
+                            self->rowstride, self->width, self->height,
+                            self->aspect_ratio);
+}
+
+/**
+ * retro_pixdata_free:
+ * @self: a #RetroPixdata
+ *
+ * Frees the given #RetroPixdata object.
+ */
+void
+retro_pixdata_free (RetroPixdata *self)
+{
+  g_return_if_fail (self != NULL);
+
+  g_slice_free (RetroPixdata, self);
+}
+
+/**
+ * retro_pixdata_get_aspect_ratio:
+ * @self: a #RetroCore
+ *
+ * Gets the aspect ratio the video should be rendered with.
+ *
+ * Returns: the aspect ratio
+ */
+gfloat
+retro_pixdata_get_aspect_ratio (RetroPixdata *self)
+{
+  g_return_val_if_fail (self != NULL, 0.f);
+
+  return self->aspect_ratio;
+}
+
+/**
+ * retro_pixdata_to_pixbuf:
+ * @self: the #RetroPixdata
+ *
+ * Creates a new #GdkPixbuf from @self.
+ *
+ * Returns: (transfer full): a new #RetroPixdata
+ */
+GdkPixbuf *
+retro_pixdata_to_pixbuf (RetroPixdata *self)
+{
+  GetRGBA8888 get_pixel;
+  gsize pixel_size;
+  rgba8888 *rgba8888_data;
+  GdkPixbuf *pixbuf;
+  gfloat x_dpi;
+  gchar *x_dpi_string;
+  gchar *y_dpi_string;
+
+  g_return_val_if_fail (self != NULL, NULL);
+
+  if (!get_interface_for_pixel_format (self->pixel_format,
+                                       &get_pixel,
+                                       &pixel_size))
+    return NULL;
+
+  rgba8888_data = g_new (rgba8888, self->width * self->height);
+  rgba8888_from_video (self->data, rgba8888_data, pixel_size,
+                       self->width, self->height, self->rowstride,
+                       get_pixel);
+
+  if (rgba8888_data == NULL)
+    return NULL;
+
+  pixbuf = gdk_pixbuf_new_from_data ((guchar *) rgba8888_data,
+                                     GDK_COLORSPACE_RGB, TRUE, 8,
+                                     self->width, self->height,
+                                     self->width * sizeof (rgba8888),
+                                     pixels_free, NULL);
+
+  x_dpi = self->aspect_ratio * RETRO_CAIRO_DISPLAY_Y_DPI;
+  x_dpi_string = g_strdup_printf ("%g", x_dpi);
+  y_dpi_string = g_strdup_printf ("%g", RETRO_CAIRO_DISPLAY_Y_DPI);
+  gdk_pixbuf_set_option (pixbuf, "x-dpi", x_dpi_string);
+  gdk_pixbuf_set_option (pixbuf, "y-dpi", y_dpi_string);
+  g_free (y_dpi_string);
+  g_free (x_dpi_string);
+
+  return pixbuf;
+}
diff --git a/retro-gtk/retro-pixdata.h b/retro-gtk/retro-pixdata.h
new file mode 100644
index 0000000..3c23057
--- /dev/null
+++ b/retro-gtk/retro-pixdata.h
@@ -0,0 +1,30 @@
+// This file is part of retro-gtk. License: GPL-3.0+.
+
+#ifndef RETRO_PIXDATA_H
+#define RETRO_PIXDATA_H
+
+#if !defined(__RETRO_GTK_INSIDE__) && !defined(RETRO_GTK_COMPILATION)
+# error "Only <retro-gtk.h> can be included directly."
+#endif
+
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+#define RETRO_TYPE_PIXDATA (retro_pixdata_get_type())
+
+GType retro_pixdata_get_type (void) G_GNUC_CONST;
+
+typedef struct _RetroPixdata RetroPixdata;
+
+RetroPixdata *retro_pixdata_copy (RetroPixdata *self);
+void retro_pixdata_free (RetroPixdata *self);
+gfloat retro_pixdata_get_aspect_ratio (RetroPixdata *self);
+GdkPixbuf *retro_pixdata_to_pixbuf (RetroPixdata *self);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (RetroPixdata, retro_pixdata_free)
+
+G_END_DECLS
+
+#endif /* RETRO_PIXDATA_H */