diff --git a/include/render/bitmap.h b/include/render/bitmap.h
index 28f5a16..5be28bf 100644
--- a/include/render/bitmap.h
+++ b/include/render/bitmap.h
@@ -8,30 +8,36 @@
 
 struct bitmap_rich_8
 {
-	uint32_t size_x,
-	uint32_t size_y,
+	uint32_t size_px_x; // largeur en pixels
+	uint32_t size_px_y; // hauteur en pixels
+	uint32_t size_o_y; // taille en octets d'une rangée
 
-	uint8_t * color;
-	uint8_t * layout;
+	uint8_t * color; // bitmap monochrome
+	uint8_t * layout; // transparence
 };
+typedef struct bitmap_rich_16 bitmap_rich_16;
 
 struct bitmap_rich_16
 {
-	uint32_t size_x,
-	uint32_t size_y,
+	uint32_t size_px_x;
+	uint32_t size_px_y;
+	uint32_t size_o_y;
 
 	uint16_t * color;
 	uint16_t * layout;
 };
+typedef struct bitmap_rich_16 bitmap_rich_16;
 
 struct bitmap_rich_32
 {
-	uint32_t size_x,
-	uint32_t size_y,
+	uint32_t size_px_x;
+	uint32_t size_px_y;
+	uint32_t size_o_y;
 
 	uint32_t * color;
 	uint32_t * layout;
 };
+typedef struct bitmap_rich_32 bitmap_rich_32;
 
 
 /* bitmap_get_color_<type>(int x, int y)
@@ -39,6 +45,6 @@ struct bitmap_rich_32
    byte 7 -> layout (visible, invisible)
    byte 6 -> color (N || B) */
 
-uint8_t bitmap_get_color_8(int x, int y);
-uint8_t bitmap_get_color_16(int x, int y);
-uint8_t bitmap_get_color_32(int x, int y);
\ No newline at end of file
+uint8_t bitmap_get_color_8(const bitmap_rich_8 * bmp,uint32_t x, uint32_t y);
+uint8_t bitmap_get_color_16(const bitmap_rich_16 * bmp,uint32_t x, uint32_t y);
+uint8_t bitmap_get_color_32(const bitmap_rich_32 * bmp,uint32_t x, uint32_t y);
\ No newline at end of file
diff --git a/src/render/bitmap.c b/src/render/bitmap.c
index 3b61809..776a6d9 100644
--- a/src/render/bitmap.c
+++ b/src/render/bitmap.c
@@ -1 +1,6 @@
-#include <bitmap.h>
\ No newline at end of file
+#include <bitmap.h>
+
+uint8_t bitmap_get_color_8(const bitmap_rich_8 * bmp, uint32_t x, uint32_t y)
+{
+	uint32_t indice=x*bitmap
+}
\ No newline at end of file