texture

1 files changed, 23 insertions, 4 deletions

diff --git a/sponge.h b/sponge.h
index 2978e0e..5229bd9 100644
--- a/sponge.h
+++ b/sponge.h
@@ -1,15 +1,15 @@
 #include <stdint.h>
 
 typedef struct {
-    // TODO(kard): define byte order
-    uint32_t *pixels;
+    uint32_t *pixels; // AARRGGBB
     uint32_t width;
     uint32_t height;
     uint32_t stride;
 } sponge_Texture;
 
-void sponge_clear(sponge_Texture c, uint32_t color);
-void sponge_draw_rect(sponge_Texture c, uint32_t x0, uint32_t y0, uint32_t x1, uint32_t y1, uint32_t color);
+void sponge_clear       (sponge_Texture c, uint32_t color);
+void sponge_draw_rect   (sponge_Texture c, uint32_t x0, uint32_t y0, uint32_t x1, uint32_t y1, uint32_t color);
+void sponge_draw_texture(sponge_Texture c, uint32_t x0, uint32_t y0, sponge_Texture tex);
 
 // TODO(kard): prefix stripping
 
@@ -31,5 +31,24 @@ void sponge_draw_rect(sponge_Texture c, uint32_t x0, uint32_t y0, uint32_t x1, u
     }
 }
 
+void sponge_draw_texture(sponge_Texture c, uint32_t x0, uint32_t y0, sponge_Texture tex) {
+    uint32_t *row_dst = c.pixels + (y0 * c.stride);
+    uint32_t *row_src = tex.pixels;
+    uint32_t x1 = x0 + tex.width;
+    uint32_t y1 = y0 + tex.height;
+
+    if (x1 >= c.width)
+        x1 = c.width - 1;
+    if (y1 >= c.height)
+        y1 = c.height - 1;
+
+    for (uint32_t y = y0; y <= y1; y++, row_src += tex.stride, row_dst += c.stride) {
+        // TODO(kard): memcpy?
+        for (uint32_t x = x0, x_src = 0; x <= x1; x++, x_src++) {
+            row_dst[x] = row_src[x_src];
+        }
+    }
+}
+
 #endif // SPONGE_IMPLEMENTATION