From 927176bc16aa2d321e7e98dd9f01a6e2004c5001 Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Mon, 27 Jun 2016 21:27:57 -0700 Subject: GUI: Add code to draw simple graphics Add code to draw simple graphics, namely lines(solid or dashed) and circles. Signed-off-by: Andrey Smirnov Signed-off-by: Sascha Hauer --- lib/gui/2d-primitives.c | 199 ++++++++++++++++++++++++++++++++++++++++++++++++ lib/gui/Kconfig | 3 + lib/gui/Makefile | 1 + 3 files changed, 203 insertions(+) create mode 100644 lib/gui/2d-primitives.c (limited to 'lib') diff --git a/lib/gui/2d-primitives.c b/lib/gui/2d-primitives.c new file mode 100644 index 0000000000..f3814eea44 --- /dev/null +++ b/lib/gui/2d-primitives.c @@ -0,0 +1,199 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +static void __illuminate(struct fb_info *info, + int x, int y, + u8 r, u8 g, u8 b, u8 a) +{ + void *pixel; + + pixel = fb_get_screen_base(info); + pixel += y * info->line_length + x * (info->bits_per_pixel >> 3); + + gu_set_rgba_pixel(info, pixel, r, g, b, a); +} + +static void illuminate(struct fb_info *info, + bool invert, + int x, int y, + u8 r, u8 g, u8 b, u8 a) +{ + if (invert) + __illuminate(info, y, x, + r, g, b, a); + else + __illuminate(info, x, y, + r, g, b, a); + +} + + +static void draw_simple_line(struct screen *sc, + int x1, int y1, + int x2, int y2, + u8 r, u8 g, u8 b, u8 a, + unsigned int dash) +{ + int x; + bool invert = false; + unsigned int pixel = 0; + + BUG_ON(x1 != x2 && + y1 != y2); + + if (x1 == x2) { + swap(x1, y1); + swap(x2, y2); + invert = true; + } + + if (x1 > x2) { + swap(x1, x2); + swap(y1, y2); + } + + for (x = x1; x < x2 - 1; x++) { + if (!dash || + (++pixel % (2 * dash)) < dash) + illuminate(sc->info, + invert, + x, y1, + r, g, b, a); + } +} + +/** + * gl_draw_line - draw a 2D dashed line between (x1, y1) and (x2,y2) + * + * @sc: screen to draw on + * @x1, @y1: first point defining the line + * @x2, @y2: second point defining the line + * @r, @g, @b, @a: line's color + * @dash: dash length (0 denotes solid line) + * + * gl_draw_line() implements integer version of Bresenham's algoritm + * as can be found here: + * + * http://www.idav.ucdavis.edu/education/GraphicsNotes/Bresenhams-Algorithm.pdf + */ +void gu_draw_line(struct screen *sc, + int x1, int y1, + int x2, int y2, + u8 r, u8 g, u8 b, u8 a, + unsigned int dash) +{ + int dx; + int dy; + int i, j, eps; + bool invert = false; + unsigned int pixel = 0; + + BUG_ON(x1 < 0 || y1 < 0 || + x2 < 0 || y2 < 0); + + if (x1 == x2 || y1 == y2) { + draw_simple_line(sc, + x1, y1, + x2, y2, + r, g, b, a, dash); + return; + } + + dx = abs(x2 - x1); + dy = abs(y2 - y1); + + /* + * First thing we need to determine "Driving Axis", as can be + * seen below if Y-axis projection of the line is bigger than + * X-axis projection we swap axes and pretend the X is Y and + * vice versa + */ + if (dy > dx) { + swap(x1, y1); + swap(x2, y2); + swap(dx, dy); + invert = true; + } + + /* + * Second, we need to make sure that we will be traversing + * driving axis in the direction of increment so we swap point + * 1 with point 2 if x1 is greater than x2 + */ + if (x1 > x2) { + swap(x1, x2); + swap(y1, y2); + } + + j = y1; + eps = dy - dx; + + for (i = x1; i <= x2 - 1; i++) { + if (!dash || + (++pixel % (2 * dash)) > dash) { + illuminate(sc->info, + invert, + j, i, + r, g, b, a); + } else { + printf("NOT illuminating pixel: %d\n", pixel); + } + + if (eps >= 0) { + j += 1; + eps -= dx; + } + + eps += dy; + } +} + +/** + * gl_draw_circle - draw a 2D circle with center at (x0, y0) + * + * @sc: screen to draw on + * @x0, @y0: coordinates of circle's center + * @radius: circle's radius + * @r, @g, @b, @a: circle's color + + * + * gu_draw_circle() implements midpoint circle algorithm as can be + * found here: + * + * https://en.wikipedia.org/wiki/Midpoint_circle_algorithm + */ +void gu_draw_circle(struct screen *sc, + int x0, int y0, int radius, + u8 r, u8 g, u8 b, u8 a) +{ + int x = radius; + int y = 0; + int e = 0; + + BUG_ON(x0 < 0 || y0 < 0 || radius < 0); + + while (x >= y) { + __illuminate(sc->info, x0 + x, y0 + y, r, g, b, a); + __illuminate(sc->info, x0 + y, y0 + x, r, g, b, a); + __illuminate(sc->info, x0 - y, y0 + x, r, g, b, a); + __illuminate(sc->info, x0 - x, y0 + y, r, g, b, a); + __illuminate(sc->info, x0 - x, y0 - y, r, g, b, a); + __illuminate(sc->info, x0 - y, y0 - x, r, g, b, a); + __illuminate(sc->info, x0 + y, y0 - x, r, g, b, a); + __illuminate(sc->info, x0 + x, y0 - y, r, g, b, a); + + y += 1; + e += 1 + 2 * y; + + if (2 * (e - x) + 1 > 0) { + x -= 1; + e += 1 - 2 * x; + } + } +} diff --git a/lib/gui/Kconfig b/lib/gui/Kconfig index eac9597e2d..2625d9fb2f 100644 --- a/lib/gui/Kconfig +++ b/lib/gui/Kconfig @@ -6,6 +6,9 @@ config IMAGE_RENDERER if IMAGE_RENDERER +config 2D_PRIMITIVES + bool + config BMP bool "bmp" diff --git a/lib/gui/Makefile b/lib/gui/Makefile index d4b26c47b8..31e66225d7 100644 --- a/lib/gui/Makefile +++ b/lib/gui/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_IMAGE_RENDERER) += image_renderer.o graphic_utils.o obj-$(CONFIG_PNG) += png.o obj-$(CONFIG_LODEPNG) += png_lode.o lodepng.o obj-$(CONFIG_PICOPNG) += png_pico.o picopng.o +obj-$(CONFIG_2D_PRIMITIVES) += 2d-primitives.o -- cgit v1.2.3