271 lines
6.7 KiB
C
271 lines
6.7 KiB
C
/*
|
|
* Gem-graph OpenGL experiments
|
|
*
|
|
* Desc: OpenGL utils header
|
|
*
|
|
* Copyright (C) 2023 Arthur Menges <arthur.menges@a-lec.org>
|
|
* Copyright (C) 2023 Adrien Bourmault <neox@a-lec.org>
|
|
* Copyright (C) 2023 Jean Sirmai <jean@a-lec.org>
|
|
*
|
|
* This file is part of Gem-graph.
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero General Public License as published by
|
|
* the Free Software Foundation, either version 3 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 Affero General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Affero General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#pragma once
|
|
#include "base.h"
|
|
#include <unistd.h>
|
|
#include <stdbool.h>
|
|
#include <epoxy/gl.h>
|
|
#include <GL/glu.h>
|
|
#include <GL/glext.h>
|
|
|
|
/*
|
|
* Structure describing a gl_area and its parameters, used to create a table
|
|
* of Gem-graph client current gl_areas
|
|
*/
|
|
struct gl_area_entry {
|
|
char name[16];
|
|
GLuint vao; // init_buffers
|
|
GLuint position_buffer; // shutdown, draw
|
|
GLuint color_buffer; // shutdown, draw
|
|
GLuint program; // shutdown, init_shaders, draw
|
|
GLuint m; // init_shaders, draw
|
|
GLuint v; // init_shaders, draw
|
|
GLuint p; // init_shaders, draw
|
|
// GLuint line_indices_nb; // now : graphics.c > int buffer_lines_ndx
|
|
// GLuint plan_indices_nb; // now : graphics.c > int buffer_plans_ndx
|
|
};
|
|
|
|
/*
|
|
* Find gl_area_entry from a gl_area ptr
|
|
*
|
|
* @param gl_area, ptr to the gl_area widget
|
|
*
|
|
*
|
|
* @return entry ptr
|
|
*/
|
|
struct gl_area_entry *graphics_find_glarea_from_ptr(const char *name);
|
|
|
|
/*
|
|
* Initializes a gl_area
|
|
*
|
|
* @param gl_area, ptr to the gl_area widget
|
|
*
|
|
* @return true if initialized
|
|
*/
|
|
bool graphics_init(const char *gl_area);
|
|
|
|
/*
|
|
* Draws the current buffer to a gl_area
|
|
*
|
|
* @param gl_area, ptr to the gl_area widget
|
|
*
|
|
* @return void
|
|
*/
|
|
void graphics_draw(const void *gl_area);
|
|
|
|
/*
|
|
* Shutdowns a gl_area
|
|
*
|
|
* @param gl_area, ptr to the gl_area widget
|
|
*
|
|
* @return true if success
|
|
*/
|
|
bool graphics_shutdown(const void *gl_area);
|
|
|
|
/*
|
|
* Initializes the shaders of a gl_area and link them to a program
|
|
*
|
|
* @param gl_area, ptr to the gl_area widget
|
|
*
|
|
* @return true if initialized
|
|
*/
|
|
bool graphics_init_shaders(const void *gl_area);
|
|
|
|
/* Initializes the buffer of a gl_area
|
|
* Calls according to the user preferences
|
|
* @param gl_area, ptr to the gl_area widget
|
|
* @return void
|
|
*/
|
|
void graphics_init_buffers(const void *gl_area);
|
|
|
|
/*
|
|
* Writes values to describe a line from a to b into the line buffer
|
|
*
|
|
* @param coords GLuint (a,b)
|
|
*
|
|
* @return void
|
|
*/
|
|
void graphics_write_line (GLuint a, GLuint b);
|
|
|
|
/*
|
|
* Writes values to describe a vertex at (x,y,z) into the vertex buffer
|
|
*
|
|
* @param coords GLfloat(x,y,z)
|
|
*
|
|
* @return void
|
|
*/
|
|
void graphics_write_vertex (GLfloat x, GLfloat y, GLfloat z);
|
|
|
|
/*
|
|
* Writes values to describe a color (r,g,b) into the color buffer
|
|
*
|
|
* @param color GLfloat(r,g,b)
|
|
*
|
|
* @return void
|
|
*/
|
|
void graphics_write_color (GLfloat r, GLfloat g, GLfloat b);
|
|
|
|
/*
|
|
* Writes values to describe an (a,b,c) plan (triangle) into the plan buffer
|
|
*
|
|
* @param coords GLuint (a,b,c)
|
|
*
|
|
* @return void
|
|
*/
|
|
void graphics_write_plan (GLuint a, GLuint b, GLuint c);
|
|
|
|
/*
|
|
* Initializes an identity matrix
|
|
*
|
|
* @param res, target ptr
|
|
*
|
|
* @return void
|
|
*/
|
|
static inline void compute_i(float *res)
|
|
{
|
|
/* initialize to the identity matrix */
|
|
res[0] = 1.f; res[4] = 0.f; res[8] = 0.f; res[12] = 0.f;
|
|
res[1] = 0.f; res[5] = 1.f; res[9] = 0.f; res[13] = 0.f;
|
|
res[2] = 0.f; res[6] = 0.f; res[10] = 1.f; res[14] = 0.f;
|
|
res[3] = 0.f; res[7] = 0.f; res[11] = 0.f; res[15] = 1.f;
|
|
}
|
|
|
|
/*
|
|
* Computes the projection matrix
|
|
*
|
|
* @param res, target ptr
|
|
* phi, XXX
|
|
* theta, XXX
|
|
* psi, XXX
|
|
*
|
|
* @return void
|
|
*/
|
|
static inline void compute_mvp(float *res, float phi, float theta, float psi)
|
|
{
|
|
float x = phi *(G_PI / 180.f);
|
|
float y = theta *(G_PI / 180.f);
|
|
float z = psi *(G_PI / 180.f);
|
|
float c1 = cosf(x), s1 = sinf(x);
|
|
float c2 = cosf(y), s2 = sinf(y);
|
|
float c3 = cosf(z), s3 = sinf(z);
|
|
float c3c2 = c3 * c2;
|
|
float s3c1 = s3 * c1;
|
|
float c3s2s1 = c3 * s2 * s1;
|
|
float s3s1 = s3 * s1;
|
|
float c3s2c1 = c3 * s2 * c1;
|
|
float s3c2 = s3 * c2;
|
|
float c3c1 = c3 * c1;
|
|
float s3s2s1 = s3 * s2 * s1;
|
|
float c3s1 = c3 * s1;
|
|
float s3s2c1 = s3 * s2 * c1;
|
|
float c2s1 = c2 * s1;
|
|
float c2c1 = c2 * c1;
|
|
|
|
compute_i(res);
|
|
|
|
/* apply all three rotations using the three matrices:
|
|
*
|
|
* ⎡ c3 s3 0 ⎤ ⎡ c2 0 -s2 ⎤ ⎡ 1 0 0 ⎤
|
|
* ⎢ -s3 c3 0 ⎥ ⎢ 0 1 0 ⎥ ⎢ 0 c1 s1 ⎥
|
|
* ⎣ 0 0 1 ⎦ ⎣ s2 0 c2 ⎦ ⎣ 0 -s1 c1 ⎦
|
|
*/
|
|
res[0] = c3c2; res[4] = s3c1 + c3s2s1; res[8] = s3s1 - c3s2c1; res[12] = 0.f;
|
|
res[1] = -s3c2; res[5] = c3c1 - s3s2s1; res[9] = c3s1 + s3s2c1; res[13] = 0.f;
|
|
res[2] = s2; res[6] = -c2s1; res[10] = c2c1; res[14] = 0.f;
|
|
res[3] = 0.f; res[7] = 0.f; res[11] = 0.f; res[15] = 1.f;
|
|
}
|
|
|
|
/*
|
|
* Created and compile a shader
|
|
*
|
|
* @param type, shader type
|
|
* src, source code of shader
|
|
*
|
|
* @return shader id
|
|
*/
|
|
static inline GLuint create_shader(int type, const char *src)
|
|
{
|
|
GLuint shader;
|
|
int status;
|
|
|
|
shader = glCreateShader(type);
|
|
glShaderSource(shader, 1, &src, NULL);
|
|
glCompileShader(shader);
|
|
|
|
glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
|
|
if(status == GL_FALSE) {
|
|
int log_len;
|
|
char *buffer;
|
|
|
|
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &log_len);
|
|
|
|
buffer = g_malloc(log_len + 1);
|
|
assert (buffer);
|
|
glGetShaderInfoLog(shader, log_len, NULL, buffer);
|
|
|
|
g_warning("Compile failure in %s shader:\n%s",
|
|
type == GL_VERTEX_SHADER ? "vertex" : "fragment",
|
|
buffer);
|
|
|
|
g_free(buffer);
|
|
|
|
glDeleteShader(shader);
|
|
|
|
return 0;
|
|
}
|
|
|
|
return shader;
|
|
}
|
|
|
|
/*
|
|
* Find the gl_area_entry size
|
|
*
|
|
* @param void
|
|
*
|
|
* @return size of array
|
|
*/
|
|
extern struct gl_area_entry **gl_area_array;
|
|
static inline short gl_area_size(void)
|
|
{
|
|
struct gl_area_entry **cur;
|
|
short size;
|
|
|
|
// Check uninitialized and quit
|
|
if (gl_area_array == NULL) return 0;
|
|
|
|
cur = gl_area_array;
|
|
while(*cur) {
|
|
cur++;
|
|
size++;
|
|
}
|
|
|
|
return size;
|
|
}
|
|
|
|
/*** TEST ***/
|
|
|
|
void main_test_graphics (void);
|