1 files changed, 159 insertions, 0 deletions
diff --git a/graymap.h b/graymap.h
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--- /dev/null
+++ b/graymap.h
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+#ifndef _graymap_h_
+#define _graymap_h_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+/**
+ * @file graymap.h
+ *
+ * This header files contains thedefinition of data types and functions to deal
+ * with graymap images.
+ */
+
+/* ******************************** MACROS ************************************/
+/**
+ * This macro makes accessing graymap pixels easier.
+ * 
+ * If you use pointers to graymaps, you have to call this macro like this:
+ * GM_PIX(*my_graymap, x,y) = foo;
+ *
+ * @param gm the graymap
+ * @param x X coordinate
+ * @param y Y coordinate
+ * @return The pixel of the graymap which can be used like a variable.
+ * @see set_pix_graymap()
+ * @see get_pix_graymap()
+ * @see color_t
+ */
+#define GM_PIX(gm,x,y) (gm).data[((y)*(gm).w)+(x)]
+
+/* ****************************** DATA TYPES **********************************/
+/**
+ * This is a data type to hold RGBA color values.
+ *
+ * All values are stored as floating point numbers.
+ */
+typedef struct
+{
+	double r; /**< Red color component. */
+	double g; /**< Green color component. */
+	double b; /**< Blue color component. */
+	double a; /**< Alpha value component. */
+} color_t;
+
+/**
+ * The data structure for graymaps.
+ */
+typedef struct
+{
+	int w; /**< Width of the image */
+	int h; /**< Height of the image. */
+	double* data; /**< Image data. */
+} graymap_t;
+
+/* ******************************* FUNCTIONS **********************************/
+/**
+ * Creating a graymap.
+ * 
+ * @param w the width of the new image.
+ * @param h the height of the new image.
+ * @return a new graymap image.
+ * @see destroy_graymap()
+ */
+extern graymap_t create_graymap(int w, int h);
+
+/**
+ * Destroying a graymap.
+ * 
+ * This will free the memory of the image data and set width/height to -1.
+ *
+ * @param gm Pointer to the graymap.
+ * @see create_graymap()
+ */
+extern void destroy_graymap(graymap_t* gm);
+
+/**
+ * Clear the graymap to a grayscale value.
+ *
+ * This will override all pixels in the graymap to the specified greyscale
+ * value.
+ *
+ * @param gm Pointer to the graymap.
+ * @param grayval Grayscale value.
+ */
+extern void clear_graymap(graymap_t* gm, double grayval);
+
+/**
+ * Set a pixel in a graymap.
+ *
+ * @param gm Pointer to the graymap
+ * @param x X coordinate
+ * @param y Y coordinate
+ * @param gray grayscale value of the pixel
+ * @see get_pix_graymap()
+ * @see GM_PIX()
+ */
+extern void set_pix_graymap(graymap_t* gm, int x, int y, double gray);
+
+/**
+ * Get a pixel from a graymap.
+ *
+ * @param gm Pointer to the graymap
+ * @param x X coordinate
+ * @param y Y coordinate
+ * @return grayscale value of the pixel
+ * @see set_pix_graymap()
+ * @see GM_PIX()
+ */
+extern double get_pix_graymap(graymap_t* gm, int x, int y);
+
+/**
+ * Blitting (copying) image data from one graymap to another.
+ *
+ * @param src pointer to the source graymap
+ * @param dst pointer to the destination graymap
+ * @param src_x Blitting start X coordinate in the source graymap
+ * @param src_y Blitting start Y coordinate in the source graymap
+ * @param dst_x Blitting start X coordinate in the destination graymap
+ * @param dst_y Blitting start Y coordinate in the destination graymap
+ * @param w Width of the blitting rectangle.
+ * @param h Height of the blitting rectangle.
+ */
+extern void blit_graymaps(graymap_t* src, graymap_t* dst, int src_x, int src_y,
+ int dst_x, int dst_y, int w, int h);
+
+/**
+ * Calculate a color from a palette and a grayscale value.
+ * 
+ * A palette is represented by two arrays. One array contains colors, the other
+ * one contains the corresponding grayscale values. This palette now represents
+ * a color gradient. The color which fits to the grayscale value will be
+ * returned.
+ *
+ * @param grayval The grayscale value.
+ * @param pal_cols Array of colors.
+ * @param pal_grays Array of grayscale values
+ * @param pal_n length of the arrays.
+ * @return The calculated color.
+ */
+extern color_t get_palette_color(double grayval, color_t* pal_cols,
+ double* pal_grays, int pal_n);
+
+/**
+ * Create a color_t object.
+ *
+ * @param r The red color component.
+ * @param g The green color component.
+ * @param b The blue color component.
+ * @param a The Alpha value.
+ * @return the color_t object.
+ * @see color_t
+ */
+extern color_t mkcol(double r, double g, double b, double a);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif