/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2005 Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): Brecht Van Lommel.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file GPU_extensions.h
 *  \ingroup gpu
 */

#ifndef __GPU_EXTENSIONS_H__
#define __GPU_EXTENSIONS_H__

#ifdef __cplusplus
extern "C" {
#endif

struct Image;
struct ImageUser;
struct PreviewImage;
	
struct GPUTexture;
typedef struct GPUTexture GPUTexture;

struct GPUFrameBuffer;
typedef struct GPUFrameBuffer GPUFrameBuffer;

struct GPUOffScreen;
typedef struct GPUOffScreen GPUOffScreen;

struct GPUShader;
typedef struct GPUShader GPUShader;

struct GPUProgram;
typedef struct GPUProgram GPUProgram;

/* GPU extensions support */

void GPU_extensions_disable(void);

bool GPU_glsl_support(void);
bool GPU_non_power_of_two_support(void);
bool GPU_vertex_buffer_support(void);
bool GPU_display_list_support(void);
bool GPU_bicubic_bump_support(void);
bool GPU_geometry_shader_support(void);
bool GPU_instanced_drawing_support(void);

int GPU_max_texture_size(void);
int GPU_color_depth(void);
void GPU_get_dfdy_factors(float fac[2]);

bool GPU_mem_stats_supported(void);
void GPU_mem_stats_get(int *totalmem, int *freemem);

void GPU_code_generate_glsl_lib(void);

/* GPU Types */

typedef enum GPUDeviceType {
	GPU_DEVICE_NVIDIA =     (1<<0),
	GPU_DEVICE_ATI =        (1<<1),
	GPU_DEVICE_INTEL =      (1<<2),
	GPU_DEVICE_SOFTWARE =   (1<<3),
	GPU_DEVICE_UNKNOWN =    (1<<4),
	GPU_DEVICE_ANY =        (0xff)
} GPUDeviceType;

typedef enum GPUOSType {
	GPU_OS_WIN =            (1<<8),
	GPU_OS_MAC =            (1<<9),
	GPU_OS_UNIX =           (1<<10),
	GPU_OS_ANY =            (0xff00)
} GPUOSType;

typedef enum GPUDriverType {
	GPU_DRIVER_OFFICIAL =   (1<<16),
	GPU_DRIVER_OPENSOURCE = (1<<17),
	GPU_DRIVER_SOFTWARE =   (1<<18),
	GPU_DRIVER_ANY =        (0xff0000)
} GPUDriverType;

bool GPU_type_matches(GPUDeviceType device, GPUOSType os, GPUDriverType driver);

/* GPU Texture
 * - always returns unsigned char RGBA textures
 * - if texture with non square dimensions is created, depending on the
 *   graphics card capabilities the texture may actually be stored in a
 *   larger texture with power of two dimensions. the actual dimensions
 *   may be queried with GPU_texture_opengl_width/height. GPU_texture_coord_2f
 *   calls glTexCoord2f with the coordinates adjusted for this.
 * - can use reference counting:
 *     - reference counter after GPU_texture_create is 1
 *     - GPU_texture_ref increases by one
 *     - GPU_texture_free decreases by one, and frees if 0
 *  - if created with from_blender, will not free the texture
 */

typedef enum GPUHDRType {
	GPU_HDR_NONE =       0,
	GPU_HDR_HALF_FLOAT = 1,
	GPU_HDR_FULL_FLOAT = (1 << 1),
} GPUHDRType;

GPUTexture *GPU_texture_create_1D(int w, const float *pixels, char err_out[256]);
GPUTexture *GPU_texture_create_2D(int w, int h, const float *pixels, GPUHDRType hdr, char err_out[256]);
GPUTexture *GPU_texture_create_3D(int w, int h, int depth, int channels, const float *fpixels);
GPUTexture *GPU_texture_create_depth(int w, int h, char err_out[256]);
GPUTexture *GPU_texture_create_vsm_shadow_map(int size, char err_out[256]);
GPUTexture *GPU_texture_create_2D_procedural(int w, int h, const float *pixels, bool repeat, char err_out[256]);
GPUTexture *GPU_texture_create_1D_procedural(int w, const float *pixels, char err_out[256]);
GPUTexture *GPU_texture_from_blender(struct Image *ima,
	struct ImageUser *iuser, bool is_data, double time, int mipmap);
GPUTexture *GPU_texture_from_preview(struct PreviewImage *prv, int mipmap);
void GPU_invalid_tex_init(void);
void GPU_invalid_tex_bind(int mode);
void GPU_invalid_tex_free(void);

void GPU_texture_free(GPUTexture *tex);

void GPU_texture_ref(GPUTexture *tex);

void GPU_texture_bind(GPUTexture *tex, int number);
void GPU_texture_unbind(GPUTexture *tex);

void GPU_texture_filter_mode(GPUTexture *tex, bool compare, bool use_filter);

GPUFrameBuffer *GPU_texture_framebuffer(GPUTexture *tex);

int GPU_texture_target(const GPUTexture *tex);
int GPU_texture_opengl_width(const GPUTexture *tex);
int GPU_texture_opengl_height(const GPUTexture *tex);
int GPU_texture_opengl_bindcode(const GPUTexture *tex);

/* GPU Framebuffer
 * - this is a wrapper for an OpenGL framebuffer object (FBO). in practice
 *   multiple FBO's may be created, to get around limitations on the number
 *   of attached textures and the dimension requirements.
 * - after any of the GPU_framebuffer_* functions, GPU_framebuffer_restore must
 *   be called before rendering to the window framebuffer again */

void GPU_texture_bind_as_framebuffer(GPUTexture *tex);

GPUFrameBuffer *GPU_framebuffer_create(void);
int GPU_framebuffer_texture_attach(GPUFrameBuffer *fb, GPUTexture *tex, int slot, char err_out[256]);
void GPU_framebuffer_texture_detach(GPUTexture *tex);
void GPU_framebuffer_slots_bind(GPUFrameBuffer *fb, int slot);
void GPU_framebuffer_texture_unbind(GPUFrameBuffer *fb, GPUTexture *tex);
void GPU_framebuffer_free(GPUFrameBuffer *fb);
bool GPU_framebuffer_check_valid(GPUFrameBuffer *fb, char err_out[256]);

void GPU_framebuffer_bind_no_save(GPUFrameBuffer *fb, int slot);

void GPU_framebuffer_restore(void);
void GPU_framebuffer_blur(GPUFrameBuffer *fb, GPUTexture *tex, GPUFrameBuffer *blurfb, GPUTexture *blurtex);

/* GPU OffScreen
 * - wrapper around framebuffer and texture for simple offscreen drawing
 * - changes size if graphics card can't support it */

GPUOffScreen *GPU_offscreen_create(int width, int height, char err_out[256]);
void GPU_offscreen_free(GPUOffScreen *ofs);
void GPU_offscreen_bind(GPUOffScreen *ofs, bool save);
void GPU_offscreen_unbind(GPUOffScreen *ofs, bool restore);
void GPU_offscreen_read_pixels(GPUOffScreen *ofs, int type, void *pixels);
int GPU_offscreen_width(const GPUOffScreen *ofs);
int GPU_offscreen_height(const GPUOffScreen *ofs);

/* Builtin/Non-generated shaders */
typedef enum GPUProgramType {
	GPU_PROGRAM_TYPE_FRAGMENT = 0
} GPUProgramType;


GPUProgram *GPU_program_shader_create(GPUProgramType type, const char *code);
void GPU_program_free(GPUProgram *program);
void GPU_program_parameter_4f(GPUProgram *program, unsigned int location, float x, float y, float z, float w);
void GPU_program_bind(GPUProgram *);
void GPU_program_unbind(GPUProgram *);

/* GPU Shader
 * - only for fragment shaders now
 * - must call texture bind before setting a texture as uniform! */

GPUShader *GPU_shader_create(const char *vertexcode, const char *fragcode, const char *geocode, const char *libcode, const char *defines, int input, int output, int number);
enum {
	GPU_SHADER_FLAGS_NONE = 0,
	GPU_SHADER_FLAGS_SPECIAL_OPENSUBDIV = (1 << 0),
};
GPUShader *GPU_shader_create_ex(const char *vertexcode,
                                const char *fragcode,
                                const char *geocode,
                                const char *libcode,
                                const char *defines,
                                int input,
                                int output,
                                int number,
                                const int flags);
void GPU_shader_free(GPUShader *shader);

void GPU_shader_bind(GPUShader *shader);
void GPU_shader_unbind(void);

int GPU_shader_get_uniform(GPUShader *shader, const char *name);
void GPU_shader_uniform_vector(GPUShader *shader, int location, int length,
	int arraysize, const float *value);
void GPU_shader_uniform_vector_int(GPUShader *shader, int location, int length,
	int arraysize, const int *value);

void GPU_shader_uniform_texture(GPUShader *shader, int location, GPUTexture *tex);
void GPU_shader_uniform_int(GPUShader *shader, int location, int value);
void GPU_shader_geometry_stage_primitive_io(GPUShader *shader, int input, int output, int number);

int GPU_shader_get_attribute(GPUShader *shader, const char *name);

/* Builtin/Non-generated shaders */
typedef enum GPUBuiltinShader {
	GPU_SHADER_VSM_STORE         = 0,
	GPU_SHADER_SEP_GAUSSIAN_BLUR = 1,
} GPUBuiltinShader;

typedef enum GPUBuiltinProgram {
	GPU_PROGRAM_SMOKE         = 0,
	GPU_PROGRAM_SMOKE_COLORED = 1,
} GPUBuiltinProgram;

GPUShader *GPU_shader_get_builtin_shader(GPUBuiltinShader shader);
GPUProgram *GPU_shader_get_builtin_program(GPUBuiltinProgram program);
GPUShader *GPU_shader_get_builtin_fx_shader(int effects, bool persp);

void GPU_shader_free_builtin_shaders(void);

/* Vertex attributes for shaders */

#define GPU_MAX_ATTRIB 32

typedef struct GPUVertexAttribs {
	struct {
		int type;
		int glindex;
		int gltexco;
		int attribid;
		char name[64];	/* MAX_CUSTOMDATA_LAYER_NAME */
	} layer[GPU_MAX_ATTRIB];

	int totlayer;
} GPUVertexAttribs;

#ifdef __cplusplus
}
#endif

#endif  /* __GPU_EXTENSIONS_H__ */
