diff options
Diffstat (limited to 'src/shader.c')
| -rw-r--r-- | src/shader.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/src/shader.c b/src/shader.c new file mode 100644 index 0000000..e7b3bb2 --- /dev/null +++ b/src/shader.c @@ -0,0 +1,137 @@ +#include "../include/shader.h" +#include <stdio.h> +#include <assert.h> + +static int min_int(int a, int b) { + return a < b ? a : b; +} + +static unsigned int loader_shader(gsr_egl *egl, unsigned int type, const char *source) { + unsigned int shader_id = egl->glCreateShader(type); + if(shader_id == 0) { + fprintf(stderr, "gsr error: loader_shader: failed to create shader, error: %d\n", egl->glGetError()); + return 0; + } + + egl->glShaderSource(shader_id, 1, &source, NULL); + egl->glCompileShader(shader_id); + + int compiled = 0; + egl->glGetShaderiv(shader_id, GL_COMPILE_STATUS, &compiled); + if(!compiled) { + int info_length = 0; + egl->glGetShaderiv(shader_id, GL_INFO_LOG_LENGTH, &info_length); + + if(info_length > 1) { + char info_log[4096]; + egl->glGetShaderInfoLog(shader_id, min_int(4096, info_length), NULL, info_log); + fprintf(stderr, "gsr error: loader shader: failed to compile shader, error:\n%s\n", info_log); + } + + egl->glDeleteShader(shader_id); + return 0; + } + + return shader_id; +} + +static unsigned int load_program(gsr_egl *egl, const char *vertex_shader, const char *fragment_shader) { + unsigned int vertex_shader_id = 0; + unsigned int fragment_shader_id = 0; + unsigned int program_id = 0; + int linked = 0; + + if(vertex_shader) { + vertex_shader_id = loader_shader(egl, GL_VERTEX_SHADER, vertex_shader); + if(vertex_shader_id == 0) + goto err; + } + + if(fragment_shader) { + fragment_shader_id = loader_shader(egl, GL_FRAGMENT_SHADER, fragment_shader); + if(fragment_shader_id == 0) + goto err; + } + + program_id = egl->glCreateProgram(); + if(program_id == 0) { + fprintf(stderr, "gsr error: load_program: failed to create shader program, error: %d\n", egl->glGetError()); + goto err; + } + + if(vertex_shader_id) + egl->glAttachShader(program_id, vertex_shader_id); + + if(fragment_shader_id) + egl->glAttachShader(program_id, fragment_shader_id); + + egl->glLinkProgram(program_id); + + egl->glGetProgramiv(program_id, GL_LINK_STATUS, &linked); + if(!linked) { + int info_length = 0; + egl->glGetProgramiv(program_id, GL_INFO_LOG_LENGTH, &info_length); + + if(info_length > 1) { + char info_log[4096]; + egl->glGetProgramInfoLog(program_id, min_int(4096, info_length), NULL, info_log); + fprintf(stderr, "gsr error: load program: linking shader program failed, error:\n%s\n", info_log); + } + + goto err; + } + + if(fragment_shader_id) + egl->glDeleteShader(fragment_shader_id); + if(vertex_shader_id) + egl->glDeleteShader(vertex_shader_id); + + return program_id; + + err: + if(program_id) + egl->glDeleteProgram(program_id); + if(fragment_shader_id) + egl->glDeleteShader(fragment_shader_id); + if(vertex_shader_id) + egl->glDeleteShader(vertex_shader_id); + return 0; +} + +int gsr_shader_init(gsr_shader *self, gsr_egl *egl, const char *vertex_shader, const char *fragment_shader) { + assert(egl); + self->egl = egl; + self->program_id = 0; + + if(!vertex_shader && !fragment_shader) { + fprintf(stderr, "gsr error: gsr_shader_init: vertex shader and fragment shader can't be NULL at the same time\n"); + return -1; + } + + self->program_id = load_program(self->egl, vertex_shader, fragment_shader); + if(self->program_id == 0) + return -1; + + return 0; +} + +void gsr_shader_deinit(gsr_shader *self) { + if(self->program_id) { + self->egl->glDeleteProgram(self->program_id); + self->program_id = 0; + } +} + +int gsr_shader_bind_attribute_location(gsr_shader *self, const char *attribute, int location) { + while(self->egl->glGetError()) {} + self->egl->glBindAttribLocation(self->program_id, location, attribute); + return self->egl->glGetError(); +} + +void gsr_shader_use(gsr_shader *self) { + self->egl->glUseProgram(self->program_id); +} + +void gsr_shader_use_none(gsr_shader *self) { + self->egl->glUseProgram(0); +} |