added clipping rectangles

[winnie] / src / gfx.cc

diff --git a/src/gfx.cc b/src/gfx.cc
new file mode 100644 (file)
index 0000000..1da2953
--- /dev/null
+++ b/src/gfx.cc
@@ -0,0 +1,155 @@
+#include <string.h>
+
+#include "geom.h"
+#include "gfx.h"
+
+static Rect clipping_rect;
+
+void set_clipping_rect(const Rect &rect)
+{
+       clipping_rect = rect_intersection(rect, get_screen_size());
+}
+
+const Rect &get_clipping_rect()
+{
+       return clipping_rect;
+}
+
+void clear_screen(int r, int g, int b)
+{
+       Rect screen_rect = get_screen_size();
+       fill_rect(screen_rect, r, g, b);
+}
+
+void fill_rect(const Rect &rect, int r, int g, int b)
+{
+       Rect drect = rect;
+       Rect screen_rect = get_screen_size();
+
+       if(drect.x < clipping_rect.x) {
+               drect.width -= clipping_rect.x - drect.x;
+               drect.x = clipping_rect.x;
+       }
+
+       if(drect.y < clipping_rect.y) {
+               drect.height -= clipping_rect.y - drect.y;
+               drect.y = clipping_rect.y;
+       }
+
+       if(drect.x + drect.width >= clipping_rect.x + clipping_rect.width) {
+               drect.width = clipping_rect.width + clipping_rect.x - drect.x;
+       }
+
+       if(drect.y + drect.height >= clipping_rect.y + clipping_rect.height) {
+               drect.height = clipping_rect.height + clipping_rect.y - drect.y;
+       }
+
+       unsigned char *fb = get_framebuffer() + (drect.x + screen_rect.width * drect.y) * 4;
+       for(int i=0; i<drect.height; i++) {
+               for(int j=0; j<drect.width; j++) {
+                       fb[j * 4] = b;
+                       fb[j * 4 + 1] = g;
+                       fb[j * 4 + 2] = r;
+               }
+               fb += screen_rect.width * 4;
+       }
+}
+
+void blit(unsigned char *src_img, const Rect &src_rect, unsigned char* dest_img,
+               const Rect &dest_rect, int dest_x, int dest_y)
+{
+       Rect irect = rect_intersection(get_clipping_rect(), dest_rect);
+
+       int width = src_rect.width;
+       int height = src_rect.height;
+
+       int xoffs = dest_x - irect.x;
+       if(xoffs < 0) {
+               dest_x = irect.x;
+               width += xoffs;
+       }
+
+       int yoffs = dest_y - irect.y;
+       if(yoffs < 0) {
+               dest_y = irect.y;
+               height += yoffs;
+       }
+
+       int xend = dest_x + width;
+       if(xend >= irect.width) {
+               width -= xend - irect.width;
+       }
+
+       int yend = dest_y + height;
+       if(yend >= irect.height) {
+               height -= yend - irect.height;
+       }
+
+       if(width <= 0 || height <= 0) {
+               return;
+       }
+
+       unsigned char *sptr = src_img + (src_rect.y * src_rect.width + src_rect.x) * 4;
+       unsigned char *dptr = dest_img + (dest_y * dest_rect.width + dest_x) * 4;
+
+       for(int i=0; i<height; i++) {
+               memcpy(dptr, sptr, width * 4);
+               sptr += src_rect.width * 4;
+               dptr += dest_rect.width * 4;
+       }
+}
+
+void blit_key(unsigned char *src_img, const Rect &src_rect, unsigned char* dest_img,
+               const Rect &dest_rect, int dest_x, int dest_y, int key_r, int key_g, int key_b)
+{
+       Rect irect = rect_intersection(get_clipping_rect(), dest_rect);
+
+       int width = src_rect.width;
+       int height = src_rect.height;
+
+       int xoffs = dest_x - irect.x;
+       if(xoffs < 0) {
+               dest_x = irect.x;
+               width += xoffs;
+       }
+
+       int yoffs = dest_y - irect.y;
+       if(yoffs < 0) {
+               dest_y = irect.y;
+               height += yoffs;
+       }
+
+       int xend = dest_x + width;
+       if(xend >= irect.width) {
+               width -= xend - irect.width;
+       }
+
+       int yend = dest_y + height;
+       if(yend >= irect.height) {
+               height -= yend - irect.height;
+       }
+
+       if(width <= 0 || height <= 0) {
+               return;
+       }
+
+       unsigned char *sptr = src_img + (src_rect.y * src_rect.width + src_rect.x) * 4;
+       unsigned char *dptr = dest_img + (dest_y * dest_rect.width + dest_x) * 4;
+
+       for(int i=0; i<height; i++) {
+               for(int j=0; j<width; j++) {
+                       int r = sptr[j * 4];
+                       int g = sptr[j * 4 + 1];
+                       int b = sptr[j * 4 + 2];
+
+                       if(r != key_r || g != key_g || b != key_b) {
+                               dptr[j * 4] = r;
+                               dptr[j * 4 + 1] = g;
+                               dptr[j * 4 + 2] = b;
+                       }
+               }
+
+               sptr += src_rect.width * 4;
+               dptr += dest_rect.width * 4;
+       }
+}