* Added the cucul_blit() function. It lets us blit various canvas one

onto the other with an optional mask.

cucul/canvas.c

@@ -65,7 +65,7 @@ void cucul_set_color(cucul_t *qq, enum cucul_color fgcolor,
  *
  *  \return The current foreground colour.
  */
-enum cucul_color cucul_get_fg_color(cucul_t *qq)
+enum cucul_color cucul_get_fg_color(cucul_t const *qq)
 {
     return qq->fgcolor;
 }
@@ -77,7 +77,7 @@ enum cucul_color cucul_get_fg_color(cucul_t *qq)
  *
  *  \return The current background colour.
  */
-enum cucul_color cucul_get_bg_color(cucul_t *qq)
+enum cucul_color cucul_get_bg_color(cucul_t const *qq)
 {
     return qq->bgcolor;
 }
@@ -226,7 +226,7 @@ void cucul_printf(cucul_t *qq, int x, int y, char const *format, ...)
  *
  *  This function fills a byte array with the character values.
  */
-void cucul_get_screen(cucul_t *qq, char *buffer)
+void cucul_get_screen(cucul_t const *qq, char *buffer)
 {
     unsigned int x, y;
 
@@ -259,3 +259,42 @@ void cucul_clear(cucul_t *qq)
     cucul_set_color(qq, oldfg, oldbg);
 }
 
+/** \brief Blit a canvas onto another one.
+ *
+ *  This function blits a canvas onto another one at the given coordinates.
+ *  An optional mask canvas can be used.
+ *
+ *  \param dst The destination canvas.
+ *  \param x X coordinate.
+ *  \param y Y coordinate.
+ *  \param src The source canvas.
+ *  \param mask The mask canvas.
+ */
+void cucul_blit(cucul_t *dst, int x, int y,
+                cucul_t const *src, cucul_t const *mask)
+{
+    int i, j, starti, startj, endi, endj;
+
+    if(src->width != mask->width || src->height != mask->height)
+        return;
+
+    starti = x < 0 ? -x : 0;
+    startj = y < 0 ? -y : 0;
+    endi = (x + src->width >= dst->width) ? dst->width - x : src->width;
+    endj = (y + src->height >= dst->height) ? dst->height - y : src->height;
+
+    for(j = startj; j < endj; j++)
+    {
+        for(i = starti; i < endi; i++)
+        {
+            if(mask && mask->chars[j * src->width + i] == (uint32_t)' ')
+                continue;
+
+            dst->chars[(j + y) * dst->width + (i + x)]
+                                           = src->chars[j * src->width + i];
+            dst->attr[(j + y) * dst->width + (i + x)]
+                                           = src->attr[j * src->width + i];
+        }
+    }
+}
+

cucul/cucul.h

@@ -128,20 +128,22 @@ char const *cucul_get_feature_name(enum cucul_feature);
 void cucul_end(cucul_t *);
 /*  @} */
 
-/** \defgroup char Character printing
+/** \defgroup canvas Canvas drawing
  *
- *  These functions provide low-level character printing routines.
+ *  These functions provide low-level character printing routines and
+ *  higher level graphics functions.
  *
  *  @{ */
 void cucul_set_color(cucul_t *, enum cucul_color, enum cucul_color);
-enum cucul_color cucul_get_fg_color(cucul_t *);
-enum cucul_color cucul_get_bg_color(cucul_t *);
+enum cucul_color cucul_get_fg_color(cucul_t const *);
+enum cucul_color cucul_get_bg_color(cucul_t const *);
 char const *cucul_get_color_name(enum cucul_color);
 void cucul_putchar(cucul_t *, int, int, char);
 void cucul_putstr(cucul_t *, int, int, char const *);
 void cucul_printf(cucul_t *, int, int, char const *, ...);
-void cucul_get_screen(cucul_t *, char *);
+void cucul_get_screen(cucul_t const *, char *);
 void cucul_clear(cucul_t *);
+void cucul_blit(cucul_t *, int, int, cucul_t const *, cucul_t const *);
 /*  @} */
 
 /** \defgroup prim Primitives drawing

test/Makefile.am

@@ -23,7 +23,7 @@ export_LDADD = ../cucul/libcucul.la @CUCUL_LIBS@
 export_CPPFLAGS = -I$(top_srcdir)/cucul
 
 gamma_SOURCES = gamma.c
-gamma_LDADD = ../caca/libcaca.la ../cucul/libcucul.la @CACA_LIBS@
+gamma_LDADD = ../caca/libcaca.la ../cucul/libcucul.la @CACA_LIBS@ @MATH_LIBS@
 gamma_CPPFLAGS = -I$(top_srcdir)/cucul -I$(top_srcdir)/caca
 
 hsv_SOURCES = hsv.c

test/gamma.c

@@ -21,6 +21,11 @@ typedef unsigned short uint16_t;
 typedef unsigned int uint32_t;
 #endif
 
+#if !defined(__KERNEL__)
+#   include <stdio.h>
+#   include <math.h>
+#endif
+
 #include "cucul.h"
 #include "caca.h"
 
@@ -28,15 +33,18 @@ uint32_t buffer[256 * 4];
 
 int main(void)
 {
-    cucul_t *qq;
+    cucul_t *qq, *gg, *mask;
     caca_t *kk;
-
     struct cucul_bitmap *left, *right;
+    float gam = 1.0;
     int x;
 
     qq = cucul_init(0, 0);
     kk = caca_attach(qq);
 
+    gg = cucul_init(cucul_get_width(qq), cucul_get_height(qq));
+    mask = cucul_init(cucul_get_width(qq), cucul_get_height(qq));
+
     for(x = 0; x < 256; x++)
     {
         buffer[x] = (x << 16) | (x << 8) | (x<< 0);
@@ -51,24 +59,50 @@ int main(void)
                                 0x00ff0000, 0x0000ff00, 0x000000ff, 0x0);
     caca_set_delay(kk, 20000);
 
-    for(x = 0; ; x = (x + 1) % 256)
+    for(x = 0; ; x++)
     {
-        float g = (x > 128) ? (256.0 + 8.0 - x) / 64.0 : (8.0 + x) / 64.0;
-
-        if(caca_get_event(kk, CACA_EVENT_KEY_PRESS))
+        int ev = caca_get_event(kk, CACA_EVENT_KEY_PRESS);
+
+        if(ev == (CACA_EVENT_KEY_PRESS | CACA_KEY_LEFT))
+            gam /= 1.03;
+        else if(ev == (CACA_EVENT_KEY_PRESS | CACA_KEY_RIGHT))
+            gam *= 1.03;
+        else if(ev == (CACA_EVENT_KEY_PRESS | CACA_KEY_DOWN))
+            gam = 1.0;
+        else if(ev == (CACA_EVENT_KEY_PRESS | CACA_KEY_ESCAPE))
             break;
 
-        cucul_draw_bitmap(qq, 0, cucul_get_height(qq) / 2,
+        /* Resize the spare canvas, just in case the main one changed */
+        cucul_set_size(gg, cucul_get_width(qq), cucul_get_height(qq));
+        cucul_set_size(mask, cucul_get_width(qq), cucul_get_height(qq));
+
+        /* Draw the regular bitmap on the main canvas */
+        cucul_draw_bitmap(qq, 0, 0,
                           cucul_get_width(qq) - 1, cucul_get_height(qq) - 1,
                           left, buffer);
 
-        cucul_set_bitmap_gamma(right, g);
-        cucul_draw_bitmap(qq, 0, 0,
-                          cucul_get_width(qq) - 1, cucul_get_height(qq) / 2 - 1,
+        /* Draw the gamma-modified bitmap on the spare canvas */
+        cucul_set_bitmap_gamma(right, gam);
+        cucul_draw_bitmap(gg, 0, 0,
+                          cucul_get_width(gg) - 1, cucul_get_height(gg) - 1,
                           right, buffer);
 
+        /* Draw something on the mask */
+        cucul_clear(mask);
+        cucul_set_color(mask, CUCUL_COLOR_WHITE, CUCUL_COLOR_WHITE);
+        cucul_fill_ellipse(mask, (1.0 + sin(0.05 * (float)x))
+                                   * 0.5 * cucul_get_width(mask),
+                                 (1.0 + cos(0.05 * (float)x))
+                                   * 0.5 * cucul_get_height(mask),
+                                 cucul_get_width(mask) / 2,
+                                 cucul_get_height(mask) / 2, '#');
+
+        /* Blit the spare canvas onto the first one */
+        cucul_blit(qq, 0, 0, gg, mask);
+
         cucul_set_color(qq, CUCUL_COLOR_WHITE, CUCUL_COLOR_BLUE);
-        cucul_printf(qq, 2, 1, "gamma=%g", g);
+        cucul_printf(qq, 2, 1,
+                     "gamma=%g - use arrows to change, Esc to quit", gam);
 
         caca_display(kk);
     }