Added SDL_DrawRect(), SDL_DrawRects(), SDL_BlendRect() and SDL_BlendRects()

Fixed line drawing so when blending a sequence of lines there are no overlapping pixels drawn.

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%404344

src/video/SDL_blendfillrect.c

@@ -203,11 +203,6 @@ SDL_BlendFillRect(SDL_Surface * dst, const SDL_Rect * rect,
         return -1;
     }
 
-    if (blendMode < SDL_BLENDMODE_BLEND) {
-        Uint32 color = SDL_MapRGBA(dst->format, r, g, b, a);
-        return SDL_FillRect(dst, rect, color);
-    }
-
     /* This function doesn't work on surfaces < 8 bpp */
     if (dst->format->BitsPerPixel < 8) {
         SDL_SetError("SDL_BlendFillRect(): Unsupported surface format");
@@ -281,11 +276,6 @@ SDL_BlendFillRects(SDL_Surface * dst, const SDL_Rect ** rects, int count,
         return -1;
     }
 
-    if (blendMode < SDL_BLENDMODE_BLEND) {
-        Uint32 color = SDL_MapRGBA(dst->format, r, g, b, a);
-        return SDL_FillRects(dst, rects, color);
-    }
-
     /* This function doesn't work on surfaces < 8 bpp */
     if (dst->format->BitsPerPixel < 8) {
         SDL_SetError("SDL_BlendFillRects(): Unsupported surface format");

src/video/SDL_blendrect.c

+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2009 Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+#include "SDL_config.h"
+
+#include "SDL_video.h"
+
+
+int
+SDL_BlendRect(SDL_Surface * dst, const SDL_Rect * rect,
+              int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
+{
+    SDL_Rect full_rect;
+    SDL_Point points[5];
+
+    if (!dst) {
+        SDL_SetError("Passed NULL destination surface");
+        return -1;
+    }
+
+    /* If 'rect' == NULL, then outline the whole surface */
+    if (!rect) {
+        full_rect.x = 0;
+        full_rect.y = 0;
+        full_rect.w = dst->w;
+        full_rect.h = dst->h;
+        rect = &full_rect;
+    }
+
+    points[0].x = rect->x;
+    points[0].y = rect->y;
+    points[1].x = rect->x+rect->w-1;
+    points[1].y = rect->y;
+    points[2].x = rect->x+rect->w-1;
+    points[2].y = rect->y+rect->h-1;
+    points[3].x = rect->x;
+    points[3].y = rect->y+rect->h-1;
+    points[4].x = rect->x;
+    points[4].y = rect->y;
+    return SDL_BlendLines(dst, points, 5, blendMode, r, g, b, a);
+}
+
+int
+SDL_BlendRects(SDL_Surface * dst, const SDL_Rect ** rects, int count,
+               int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
+{
+    int i;
+
+    for (i = 0; i < count; ++i) {
+        if (SDL_BlendRect(dst, rects[i], blendMode, r, g, b, a) < 0) {
+            return -1;
+        }
+    }
+    return 0;
+}
+
+/* vi: set ts=4 sw=4 expandtab: */

src/video/SDL_draw.h

@@ -283,7 +283,7 @@ do { \
 
 #define ABS(_x) ((_x) < 0 ? -(_x) : (_x))
 
-#define BRESENHAM(x1, y1, x2, y2, op) \
+#define BRESENHAM(x1, y1, x2, y2, op, draw_end) \
 { \
     int i, deltax, deltay, numpixels; \
     int d, dinc1, dinc2; \
@@ -325,6 +325,9 @@ do { \
     x = x1; \
     y = y1; \
  \
+    if (!draw_end) { \
+        --numpixels; \
+    } \
     for (i = 0; i < numpixels; ++i) { \
         op(x, y); \
         if (d < 0) { \
@@ -338,10 +341,11 @@ do { \
         } \
     } \
 }
-#define DRAWLINE(x0, y0, x1, y1, op)	BRESENHAM(x0, y0, x1, y1, op)
+#define DRAWLINE    BRESENHAM
 
 /*
  * Define draw rect macro
+ * (not tested, this level of optimization not needed ... yet?)
  */
 #define DRAWRECT(type, op) \
 do { \

src/video/SDL_drawline.c

@@ -46,16 +46,16 @@ SDL_DrawLine(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color)
 
     switch (dst->format->BytesPerPixel) {
     case 1:
-        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL1);
+        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL1, SDL_TRUE);
         break;
     case 2:
-        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL2);
+        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL2, SDL_TRUE);
         break;
     case 3:
         SDL_Unsupported();
         return -1;
     case 4:
-        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL4);
+        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL4, SDL_TRUE);
         break;
     }
     return 0;
@@ -96,16 +96,16 @@ SDL_DrawLines(SDL_Surface * dst, const SDL_Point * points, int count,
 
         switch (dst->format->BytesPerPixel) {
         case 1:
-            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL1);
+            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL1, SDL_TRUE);
             break;
         case 2:
-            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL2);
+            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL2, SDL_TRUE);
             break;
         case 3:
             SDL_Unsupported();
             return -1;
         case 4:
-            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL4);
+            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL4, SDL_TRUE);
             break;
         }
     }