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559 lines
14 KiB
559 lines
14 KiB
#include <SDL2/SDL.h>
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#include <GL/glew.h>
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#include <SDL2/SDL_opengl.h>
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#include <SDL2/SDL_video.h>
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#include <grapheme.h>
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#include <stdio.h>
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#include "util.h"
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#include "font.h"
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#include "ren.h"
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#define GLERR(x) \
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{ \
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int a = glGetError(); \
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if (a != GL_NO_ERROR) \
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printf("(%s:%d %s:%s) glError: 0x%x %s\n", \
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__FILE__, __LINE__, __func__, x, a, glerr[a]); \
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}
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#define GL(f) f; GLERR(#f)
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enum REN_ERR {
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REN_SUCCESS = 0,
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REN_ERRNO,
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REN_INVAL,
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REN_VERTEX,
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REN_FRAGMENT,
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REN_PROGRAM,
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REN_COMPILE,
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REN_LINK,
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REN_TEXTURE,
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REN_CONTEXT,
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REN_GLEW,
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REN_FONT,
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REN_BUFFER,
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REN_UNIFORM,
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};
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// TODO: make a macro for enum-associated string arrays
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const char * ren_err_msg[] = {
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[REN_SUCCESS] = "Success",
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[REN_ERRNO] = "Look at errno",
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[REN_INVAL] = "Invalid or NULL arguments",
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[REN_VERTEX] = "Failed to create opengl vertex shader",
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[REN_FRAGMENT] = "Failed to create opengl fragment shader",
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[REN_PROGRAM] = "Failed to create opengl program",
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[REN_COMPILE] = "Failed to compile shaders",
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[REN_LINK] = "Failed to link shaders",
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[REN_TEXTURE] = "Failed to create texture",
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[REN_CONTEXT] = "Failed to create SDL OpenGL context",
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[REN_GLEW] = "GLEW Error",
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[REN_FONT] = "Font Error",
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[REN_BUFFER] = "Failed to create opengl buffer",
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[REN_UNIFORM] = "Failed to get uniform location",
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};
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#define ELEM(x...) [x] = #x,
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const char *glerr[] = {
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ELEM(GL_INVALID_ENUM)
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ELEM(GL_INVALID_VALUE)
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ELEM(GL_INVALID_OPERATION)
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ELEM(GL_OUT_OF_MEMORY)
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};
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#undef ELEM
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// different stacks
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#include "stack.h"
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STACK_DECL(vtstack, struct v_text)
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STACK_DECL(vcstack, struct v_col)
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struct {
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SDL_GLContext *gl;
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struct font_atlas *font;
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GLuint font_texture;
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GLuint font_prog;
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GLuint box_prog;
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GLuint font_buffer;
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GLint viewsize_loc;
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GLint texturesize_loc;
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struct vtstack font_stack;
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struct vcstack box_stack;
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int width, height;
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int s_x, s_y, s_w, s_h;
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} ren = {0};
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static int ren_errno;
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// print shader compilation errors
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static int shader_compile_error(GLuint shader)
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{
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GLint status;
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glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
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if (status != GL_FALSE)
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return 0;
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GLint log_length;
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glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &log_length);
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GLchar *log_str = emalloc((log_length + 1)*sizeof(GLchar));
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glGetShaderInfoLog(shader, log_length, NULL, log_str);
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const char *shader_type_str = NULL;
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GLint shader_type;
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glGetShaderiv(shader, GL_SHADER_TYPE, &shader_type);
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switch(shader_type) {
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case GL_VERTEX_SHADER: shader_type_str = "vertex"; break;
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case GL_GEOMETRY_SHADER: shader_type_str = "geometry"; break;
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case GL_FRAGMENT_SHADER: shader_type_str = "fragment"; break;
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}
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fprintf(stderr, "Compile failure in %s shader:\n%s\n", shader_type_str, log_str);
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efree(log_str);
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return -1;
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}
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// print shader link errors
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static int shader_link_error(GLuint prog)
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{
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GLint status;
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glGetProgramiv (prog, GL_LINK_STATUS, &status);
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if (status != GL_FALSE)
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return 0;
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GLint log_length;
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glGetProgramiv(prog, GL_INFO_LOG_LENGTH, &log_length);
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GLchar *log_str = emalloc((log_length + 1)*sizeof(GLchar));
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glGetProgramInfoLog(prog, log_length, NULL, log_str);
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fprintf(stderr, "Linker failure: %s\n", log_str);
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efree(log_str);
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return -1;
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}
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#define REN_RET(a,b) {ren_errno = b; return a;}
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static GLuint shader_compile(const char *shader, GLuint type)
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{
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GLuint s;
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// initialize the vertex shader and get the corresponding id
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s = GL(glCreateShader(type))
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if (!s) REN_RET(0, REN_VERTEX)
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// get the shader into opengl
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GL(glShaderSource(s, 1, &shader, NULL))
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GL(glCompileShader(s))
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if (shader_compile_error(s))
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REN_RET(0, REN_COMPILE)
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return s;
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}
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const char * ren_strerror(void)
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{
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return ren_err_msg[ren_errno % (sizeof(ren_err_msg)/sizeof(char *))];
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}
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// compile a vertex shader (vs_path) and a fragment shader (fs_path) into an opengl
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// program and return it's index
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static GLuint ren_compile_program(const char *vs_path, const char *fs_path)
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{
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GLuint gl_vertshader, gl_fragshader, prog;
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if (!vs_path || !fs_path)
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REN_RET(0, REN_INVAL)
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char *str = NULL;
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dump_file(vs_path, &str, NULL);
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if (!str) REN_RET(0, REN_ERRNO)
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gl_vertshader = shader_compile(str, GL_VERTEX_SHADER);
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efree(str);
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if (!gl_vertshader)
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return 0;
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dump_file(fs_path, &str, NULL);
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if (!str) REN_RET(0, REN_ERRNO)
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gl_fragshader = shader_compile(str, GL_FRAGMENT_SHADER);
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efree(str);
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if (!gl_fragshader)
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return 0;
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// create the main program object, it is an amalgamation of all shaders
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prog = GL(glCreateProgram())
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if (!prog) REN_RET(0, REN_PROGRAM)
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// attach the shaders to the program (set which shaders are present)
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GL(glAttachShader(prog, gl_vertshader))
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GL(glAttachShader(prog, gl_fragshader))
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// then link the program (basically the linking stage of the program)
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GL(glLinkProgram(prog))
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if (shader_link_error(prog))
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REN_RET(0, REN_LINK)
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// after linking the shaders can be detached and the source freed from
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// memory since the program is ready to use
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GL(glDetachShader(prog, gl_vertshader))
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GL(glDetachShader(prog, gl_fragshader))
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return prog;
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}
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static GLuint ren_texturergb_2d(const char *buf, int w, int h, int upscale, int downscale)
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{
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GLuint t;
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if (!buf || w <= 0 || h <= 0)
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REN_RET(0, REN_INVAL)
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GL(glGenTextures(1, &t))
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if (!t) REN_RET(0, REN_TEXTURE)
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GL(glBindTexture(GL_TEXTURE_2D, t))
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GL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, buf))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, downscale))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, upscale))
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return t;
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}
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static GLuint ren_texturergba_2d(const char *buf, int w, int h, int upscale, int downscale)
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{
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GLuint t;
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if (!buf || w <= 0 || h <= 0)
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REN_RET(0, REN_INVAL)
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GL(glGenTextures(1, &t))
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if (!t) REN_RET(0, REN_TEXTURE)
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GL(glBindTexture(GL_TEXTURE_2D, t))
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GL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, buf))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, downscale))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, upscale))
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return t;
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}
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static GLuint ren_texturer_2d(const char *buf, int w, int h, int upscale, int downscale)
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{
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GLuint t;
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if (!buf || w <= 0 || h <= 0)
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REN_RET(0, REN_INVAL)
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GL(glGenTextures(1, &t))
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if (!t) REN_RET(0, REN_TEXTURE)
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GL(glBindTexture(GL_TEXTURE_2D, t))
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GL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, w, h, 0, GL_RED, GL_UNSIGNED_BYTE, buf))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, downscale))
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GL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, upscale))
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return t;
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}
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static GLuint ren_texturer_rect(const char *buf, int w, int h, int upscale, int downscale)
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{
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GLuint t;
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if (!buf || w <= 0 || h <= 0)
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REN_RET(0, REN_INVAL)
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GL(glGenTextures(1, &t))
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if (!t) REN_RET(0, REN_TEXTURE)
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GL(glBindTexture(GL_TEXTURE_RECTANGLE, t))
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GL(glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_RED, w, h, 0, GL_RED, GL_UNSIGNED_BYTE, buf))
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// a limitation of recatngle textures is that the wrapping mode is limited
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// to either clamp-to-edge or clamp-to-border
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GL(glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE))
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GL(glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE))
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GL(glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MIN_FILTER, downscale))
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GL(glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MAG_FILTER, upscale))
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return t;
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}
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// FIXME: update only the newly generated character instead of the whole texture
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static int update_font_texture(void)
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{
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glUseProgram(ren.font_prog);
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GL(glTexSubImage2D(
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GL_TEXTURE_RECTANGLE,
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0, 0, 0,
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ren.font->width,
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ren.font->height,
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GL_RED,
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GL_UNSIGNED_BYTE,
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ren.font->atlas))
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font_dump(ren.font, "./atlas.png");
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glUseProgram(0);
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return 0;
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}
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// TODO: push window size uniforms
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int ren_init(SDL_Window *w)
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{
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if (!w)
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REN_RET(-1, REN_INVAL)
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ren.gl = SDL_GL_CreateContext(w);
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if (!ren.gl)
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REN_RET(-1, REN_CONTEXT)
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// select some features
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GL(glEnable(GL_BLEND))
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GL(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA))
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GL(glDisable(GL_CULL_FACE))
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GL(glDisable(GL_DEPTH_TEST))
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GL(glEnable(GL_SCISSOR_TEST))
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GL(glEnable(GL_TEXTURE_2D))
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GL(glEnable(GL_TEXTURE_RECTANGLE))
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GLenum glew_err = glewInit();
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if (glew_err != GLEW_OK)
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REN_RET(glew_err, REN_GLEW);
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ren.font = font_init();
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if (!ren.font) REN_RET(-1, REN_FONT)
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if (font_load(ren.font, FONT_PATH, 20)) REN_RET(-1, REN_FONT)
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font_dump(ren.font, "./atlas.png");
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ren.font_texture = ren_texturer_rect(
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(const char *)ren.font->atlas,
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ren.font->width,
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ren.font->height,
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GL_LINEAR, GL_LINEAR);
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if (!ren.font_texture) return -1;
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ren.font_prog = ren_compile_program(FONT_VERSHADER, FONT_FRAGSHADER);
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if (!ren.font_prog) return -1;
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ren.font_stack = vtstack_init();
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ren.box_stack = vcstack_init();
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// generate the font buffer object
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GL(glGenBuffers(1, &ren.font_buffer))
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if (!ren.font_buffer) REN_RET(-1, REN_BUFFER)
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// create the uniforms, if the returned value is -1 then the uniform may have
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// been optimized away, in any case do not return, just give a warning
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ren.viewsize_loc = GL(glGetUniformLocation(ren.font_prog, "viewsize"))
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if (ren.viewsize_loc == -1)
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printf("uniform %s was optimized away\n", "viewsize");
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ren.texturesize_loc = GL(glGetUniformLocation(ren.font_prog, "texturesize"))
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if (ren.texturesize_loc == -1)
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printf("uniform %s was optimized away\n", "texturesize");
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int width, height;
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SDL_GetWindowSize(w, &width, &height);
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ren_update_viewport(width, height);
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GL(glClearColor(0.3f, 0.3f, 0.3f, 0.f))
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GL(glClear(GL_COLOR_BUFFER_BIT))
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return 0;
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}
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static int ren_draw_font_stack(void)
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{
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GL(glUseProgram(ren.font_prog))
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GL(glBindBuffer(GL_ARRAY_BUFFER, ren.font_buffer))
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GL(glViewport(0, 0, ren.width, ren.height))
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GL(glScissor(0, 0, ren.width, ren.height))
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GL(glClear(GL_COLOR_BUFFER_BIT));
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// this has caused me some trouble, convert from image coordiates to viewport
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//GL(glScissor(ren.s_x, ren.height-ren.s_y-ren.s_h, ren.s_w, ren.s_h))
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GL(glUniform2i(ren.viewsize_loc, ren.width, ren.height))
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GL(glUniform2i(ren.texturesize_loc, ren.font->width, ren.font->height))
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GL(glEnableVertexAttribArray(REN_VERTEX_IDX))
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GL(glEnableVertexAttribArray(REN_UV_IDX))
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// when passing ints to glVertexAttribPointer they are automatically
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// converted to floats
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GL(glVertexAttribPointer(
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REN_VERTEX_IDX,
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2,
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GL_INT,
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GL_FALSE,
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sizeof(struct v_text),
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0))
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GL(glVertexAttribPointer(
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REN_UV_IDX,
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2,
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GL_INT,
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GL_FALSE,
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sizeof(struct v_text),
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(void*)sizeof(vec2_i)))
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// TODO: implement size and damage tracking on stacks
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GL(glBufferData(
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GL_ARRAY_BUFFER,
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ren.font_stack.idx*sizeof(struct v_text),
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ren.font_stack.items,
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GL_DYNAMIC_DRAW))
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GL(glDrawArrays(GL_TRIANGLES, 0, ren.font_stack.idx))
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GL(glDisableVertexAttribArray(REN_VERTEX_IDX))
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GL(glDisableVertexAttribArray(REN_UV_IDX))
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GL(glBindBuffer(GL_ARRAY_BUFFER, 0))
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GL(glUseProgram(0))
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return 0;
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}
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int ren_update_viewport(int w, int h)
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{
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ren.width = w;
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ren.height = h;
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return 0;
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}
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// TODO: add a scissor array in order to do less render calls
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int ren_set_scissor(int x, int y, int w, int h)
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{
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ren.s_x = x;
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ren.s_y = y;
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ren.s_w = w;
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ren.s_h = h;
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return 0;
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}
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// TODO: implement font size
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int ren_render_text(const char *str, int x, int y, int w, int h, int size)
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{
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// x4,y4 x3,y3
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// +-------------+
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// |(x,y) /|
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// | / |
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// | 2 / |
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// | / |
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// | / |
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// | / 1 |
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// |/ |
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// +-------------+
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// x1,y1 x2,y2
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const struct font_glyph *g;
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struct font_glyph c;
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size_t ret, off;
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uint_least32_t cp;
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int updated, gx = x, gy = y;
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struct v_text v;
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printf("rendering text: %s\n", str);
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for (off = 0; (ret = grapheme_decode_utf8(str+off, SIZE_MAX, &cp)) > 0 && cp != 0; off += ret) {
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g = font_get_glyph_texture(ren.font, cp, &updated);
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if (!g) REN_RET(-1, REN_FONT);
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if (updated) {
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if (update_font_texture())
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REN_RET(-1, REN_TEXTURE);
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}
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c = *g;
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//printf("g: u=%d v=%d w=%d h=%d a=%d x=%d y=%d\n", c.u, c.v, c.w, c.h, c.a, c.x, c.y);
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//printf("v: x=%d y=%d u=%d v=%d\n", v.pos.x, v.pos.y, v.uv.u, v.uv.v);
|
|
// x1,y1
|
|
v = (struct v_text){
|
|
.pos = { .x = gx+c.x, .y = gy+c.y+c.h },
|
|
.uv = { .u = c.u, .v = c.v+c.h },
|
|
};
|
|
vtstack_push(&ren.font_stack, &v);
|
|
// x2,y2
|
|
v = (struct v_text){
|
|
.pos = { .x = gx+c.x+c.w, .y = gy+c.y+c.h },
|
|
.uv = { .u = c.u+c.w, .v = c.v+c.h },
|
|
};
|
|
vtstack_push(&ren.font_stack, &v);
|
|
// x3,y3
|
|
v = (struct v_text){
|
|
.pos = { .x = gx+c.x+c.w, .y = gy+c.y },
|
|
.uv = { .u = c.u+c.w, .v = c.v },
|
|
};
|
|
vtstack_push(&ren.font_stack, &v);
|
|
// x1,y1
|
|
v = (struct v_text){
|
|
.pos = { .x = gx+c.x, .y = gy+c.y+c.h },
|
|
.uv = { .u = c.u, .v = c.v+c.h },
|
|
};
|
|
vtstack_push(&ren.font_stack, &v);
|
|
// x3,y3
|
|
v = (struct v_text){
|
|
.pos = { .x = gx+c.x+c.w, .y = gy+c.y },
|
|
.uv = { .u = c.u+c.w, .v = c.v },
|
|
};
|
|
vtstack_push(&ren.font_stack, &v);
|
|
// x4,y4
|
|
v = (struct v_text){
|
|
.pos = { .x = gx+c.x, .y = gy+c.y },
|
|
.uv = { .u = c.u, .v = c.v },
|
|
};
|
|
vtstack_push(&ren.font_stack, &v);
|
|
|
|
// TODO: possible kerning needs to be applied here
|
|
// FIXME: advance is too large
|
|
//gx += c.w + c.a;
|
|
//gx += c.w + c.x + 1;
|
|
gx += c.x + c.a;
|
|
switch (cp) {
|
|
case '\r':
|
|
gx = x;
|
|
break;
|
|
case '\n':
|
|
// TODO: encode and/or store line height
|
|
gy = ren.font->glyph_max_h;
|
|
gx = x;
|
|
break;
|
|
default: break;
|
|
}
|
|
}
|
|
|
|
// FIXME: here we are doing one draw call for string of text which is
|
|
// inefficient but is simpler and allows for individual scissors
|
|
ren_set_scissor(x, y, w, h);
|
|
ren_draw_font_stack();
|
|
vtstack_clear(&ren.font_stack);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
int ren_free(void)
|
|
{
|
|
GL(glUseProgram(0))
|
|
GL(glBindBuffer(GL_ARRAY_BUFFER, 0))
|
|
GL(glDeleteTextures(1, &ren.font_texture))
|
|
GL(glDeleteBuffers(1, &ren.font_buffer))
|
|
SDL_GL_DeleteContext(ren.gl);
|
|
vtstack_free(&ren.font_stack);
|
|
vcstack_free(&ren.box_stack);
|
|
font_free(ren.font);
|
|
return 0;
|
|
}
|
|
|