cairo rendering

6 files changed, 125 insertions, 16 deletions

diff --git a/.gitignore b/.gitignore
index def7557..d6bc383 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 drminfo
 drmtest
+gtktest
 *.o
diff --git a/Makefile b/Makefile
index 04d7b2e..2d2f01a 100644
--- a/Makefile
+++ b/Makefile
@@ -2,13 +2,16 @@ CC	?= gcc
 CFLAGS	?= -Os -g -std=c99
 CFLAGS	+= -Wall
 
-TARGETS	:= drminfo drmtest
+TARGETS	:= drminfo drmtest gtktest
 
 drminfo : CFLAGS += $(shell pkg-config --cflags libdrm)
 drminfo : LDLIBS += $(shell pkg-config --libs libdrm)
 
-drmtest : CFLAGS += $(shell pkg-config --cflags libdrm gbm epoxy)
-drmtest : LDLIBS += $(shell pkg-config --libs libdrm gbm epoxy)
+drmtest : CFLAGS += $(shell pkg-config --cflags libdrm gbm epoxy cairo cairo-gl)
+drmtest : LDLIBS += $(shell pkg-config --libs libdrm gbm epoxy cairo cairo-gl)
+
+gtktest : CFLAGS += $(shell pkg-config --cflags gtk+-3.0 cairo)
+gtktest : LDLIBS += $(shell pkg-config --libs gtk+-3.0 cairo)
 
 all: $(TARGETS)
 
@@ -17,4 +20,5 @@ clean:
 	rm -f *~
 
 drminfo: drminfo.o drmtools.o
-drmtest: drmtest.o drmtools.o
+drmtest: drmtest.o drmtools.o render.o
+gtktest: gtktest.o render.o
diff --git a/drmtest.c b/drmtest.c
index 70501a7..cc602fb 100644
--- a/drmtest.c
+++ b/drmtest.c
@@ -18,7 +18,11 @@
 #include <epoxy/gl.h>
 #include <epoxy/egl.h>
 
+#include <cairo.h>
+#include <cairo-gl.h>
+
 #include "drmtools.h"
+#include "render.h"
 
 /* ------------------------------------------------------------------ */
 
@@ -42,6 +46,10 @@ static EGLConfig cfg;
 static EGLContext ctx;
 static EGLSurface surface;
 
+/* cairo */
+cairo_surface_t *cs;
+cairo_t *cc;
+
 /* ------------------------------------------------------------------ */
 
 static void drm_init_dev(int devnr, const char *output,
@@ -193,22 +201,21 @@ static void drm_init_dumb_fb(void)
         fprintf(stderr, "framebuffer mmap: %s\n", strerror(errno));
         exit(1);
     }
+
+    cs = cairo_image_surface_create_for_data(fbmem,
+                                             CAIRO_FORMAT_ARGB32,
+                                             creq.width,
+                                             creq.height,
+                                             creq.pitch);
 }
 
 static void drm_draw_dumb_fb(void)
 {
-    int x, y;
-    uint8_t *ptr;
-
-    for (y = 0; y < creq.height; y++) {
-        for (x = 0; x < creq.width; x++) {
-            ptr = fbmem + creq.pitch * y + 4 * x;
-            ptr[0] = 0;         /* blue  */
-            ptr[1] = x & 0xff;  /* green */
-            ptr[2] = y & 0xff;  /* red   */
-            ptr[3] = 0;         /* alpha */
-        }
-    }
+    cairo_t *cr;
+
+    cr = cairo_create(cs);
+    render_test(cr, mode->hdisplay, mode->vdisplay);
+    cairo_destroy(cr);
     drmModeDirtyFB(fd, fb_id, 0, 0);
 }
 
diff --git a/gtktest.c b/gtktest.c
new file mode 100644
index 0000000..0726bbe
--- /dev/null
+++ b/gtktest.c
@@ -0,0 +1,42 @@
+#include <cairo.h>
+#include <gtk/gtk.h>
+
+#include "render.h"
+
+static gboolean on_draw_event(GtkWidget *widget, cairo_t *cr,
+                              gpointer user_data)
+{
+    int width, height;
+
+    width = gtk_widget_get_allocated_width(widget);
+    height = gtk_widget_get_allocated_height(widget);
+    render_test(cr, width, height);
+    return FALSE;
+}
+
+int main(int argc, char *argv[])
+{
+    GtkWidget *window;
+    GtkWidget *darea;
+
+    gtk_init(&argc, &argv);
+
+    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+
+    darea = gtk_drawing_area_new();
+    gtk_container_add(GTK_CONTAINER(window), darea);
+
+    g_signal_connect(G_OBJECT(darea), "draw",
+                     G_CALLBACK(on_draw_event), NULL);
+    g_signal_connect(window, "destroy",
+                     G_CALLBACK(gtk_main_quit), NULL);
+
+    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
+    gtk_window_set_default_size(GTK_WINDOW(window), 400, 300);
+    gtk_window_set_title(GTK_WINDOW(window), "gtktest");
+
+    gtk_widget_show_all(window);
+
+    gtk_main();
+    return 0;
+}
diff --git a/render.c b/render.c
new file mode 100644
index 0000000..5c650f2
--- /dev/null
+++ b/render.c
@@ -0,0 +1,54 @@
+#include <cairo.h>
+
+static int pad = 10;
+
+static void render_color_bar(cairo_t *cr, int x, int y, int w, int h,
+                             double r, double g, double b, const char *name)
+{
+    cairo_font_extents_t ext;
+    cairo_pattern_t *gr;
+
+    gr = cairo_pattern_create_linear(x, y+h/2, w, y+h/2);
+    cairo_pattern_add_color_stop_rgb(gr, 0, 0, 0, 0);
+    cairo_pattern_add_color_stop_rgb(gr, 1, r, g, b);
+    cairo_rectangle (cr, x, y, w, h);
+    cairo_set_source (cr, gr);
+    cairo_fill (cr);
+    cairo_pattern_destroy(gr);
+
+    cairo_set_source_rgb(cr, r, g, b);
+    cairo_select_font_face(cr, "mono",
+                           CAIRO_FONT_SLANT_NORMAL,
+                           CAIRO_FONT_WEIGHT_NORMAL);
+    cairo_set_font_size(cr, h - 2*pad);
+    cairo_font_extents (cr, &ext);
+    cairo_move_to(cr, x + pad, y + pad + ext.ascent);
+    cairo_show_text(cr, name);
+}
+
+void render_test(cairo_t *cr, int width, int height)
+{
+    int bar = 100;
+
+    while (6 * bar + 2 * pad > height &&
+           bar > 4 * pad)
+        bar -= 10;
+
+    cairo_set_source_rgb(cr, 0, 0, 0);
+    cairo_rectangle (cr, 0, 0, width, height);
+    cairo_fill (cr);
+
+    cairo_set_line_width (cr, 1);
+    cairo_set_source_rgb (cr, 1, 1, 1);
+    cairo_rectangle (cr, pad - 0.5, pad - 0.5, width - 2*pad + 1, 6*bar + 1);
+    cairo_stroke (cr);
+
+    render_color_bar(cr, pad, bar * 0 + pad, width - 2*pad, bar, 1, 0, 0, "red");
+    render_color_bar(cr, pad, bar * 1 + pad, width - 2*pad, bar, 1, 1, 0, "yellow");
+    render_color_bar(cr, pad, bar * 2 + pad, width - 2*pad, bar, 0, 1, 0, "green");
+    render_color_bar(cr, pad, bar * 3 + pad, width - 2*pad, bar, 0, 1, 1, "cyan");
+    render_color_bar(cr, pad, bar * 4 + pad, width - 2*pad, bar, 0, 0, 1, "blue");
+    render_color_bar(cr, pad, bar * 5 + pad, width - 2*pad, bar, 1, 0, 1, "magenta");
+}
+
+
diff --git a/render.h b/render.h
new file mode 100644
index 0000000..93a53c5
--- /dev/null
+++ b/render.h
@@ -0,0 +1 @@
+void render_test(cairo_t *cr, int width, int height);