ascension: src/shader.c@362b7659dc76

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  * Copyright 2023 Mike Becker. All rights reserved.

     4  *

     5  * Redistribution and use in source and binary forms, with or without

     6  * modification, are permitted provided that the following conditions are met:

     7  *

     8  *   1. Redistributions of source code must retain the above copyright

     9  *      notice, this list of conditions and the following disclaimer.

    10  *

    11  *   2. Redistributions in binary form must reproduce the above copyright

    12  *      notice, this list of conditions and the following disclaimer in the

    13  *      documentation and/or other materials provided with the distribution.

    14  *

    15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    16  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    18  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    19  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    25  * POSSIBILITY OF SUCH DAMAGE.

    26  */

    28 #include "ascension/shader.h"

    29 #include "ascension/files.h"

    30 #include "ascension/error.h"

    32 #include <GL/glew.h>

    34 AscShaderProgram ASC_SHADER_FONT;

    37 AscShader asc_shader_compile(unsigned int type,

    38                              char const *code,

    39                              int length) {

    40     GLuint id = glCreateShader(type);

    41     if (id == 0) {

    42         asc_error("glCreateShader failed");

    43         return (AscShader) {0};

    44     }

    46     GLint success;

    47     glShaderSource(id, 1, &code, &length);

    48     glCompileShader(id);

    49     glGetShaderiv(id, GL_COMPILE_STATUS, &success);

    50     if (success) {

    51         asc_dprintf("Shader %u compiled", id);

    52         return (AscShader) {id};

    53     } else {

    54         char *log = malloc(1024);

    55         glGetShaderInfoLog(id, 1024, NULL, log);

    56         glDeleteShader(id);

    57         asc_error(log);

    58         free(log);

    59         return (AscShader) {0};

    60     }

    61 }

    63 AscShader asc_shader_compilef(unsigned int type,

    64                               char const *filename) {

    65     asc_file code = asc_file_mmap_rdonly(filename);

    66     if (code.ptr == NULL) {

    67         asc_error("Mapping shader file into memory failed");

    68         return (AscShader) {0};

    69     }

    70     AscShader ret = asc_shader_compile(type, code.ptr, code.length);

    71     asc_file_unmap(code);

    72     return ret;

    73 }

    75 AscShaderProgram asc_shader_link(AscShader vertex,

    76                                  AscShader fragment) {

    77     if (vertex.id == 0 || fragment.id == 0) {

    78         asc_dprintf("Skip linking shader program - shaders have not been loaded correctly.");

    79         return (AscShaderProgram) {0};

    80     }

    82     GLint success;

    83     GLint id = glCreateProgram();

    84     if (id <= 0) {

    85         asc_error("glCreateProgram failed");

    86         return (AscShaderProgram) {0};

    87     }

    88     glAttachShader(id, vertex.id);

    89     glAttachShader(id, fragment.id);

    90     glLinkProgram(id);

    91     glGetProgramiv(id, GL_LINK_STATUS, &success);

    92     glDetachShader(id, vertex.id);

    93     glDetachShader(id, fragment.id);

    94     if (success) {

    95         asc_dprintf("Shader Program %u linked (vtf: %u, frag: %u)", id, vertex.id, fragment.id);

    96         return (AscShaderProgram) {id};

    97     } else {

    98         char *log = malloc(1024);

    99         glGetProgramInfoLog(id, 1024, NULL, log);

   100         glDeleteShader(id);

   101         asc_error(log);

   102         free(log);

   103         return (AscShaderProgram) {0};

   104     }

   105 }

   107 void asc_shader_destroy(AscShader shader) {

   108     if (shader.id > 0) {

   109         asc_dprintf("Delete Shader %u", shader.id);

   110         glDeleteShader(shader.id);

   111     }

   112     shader.id = 0;

   113 }

   115 void asc_shader_program_destroy(AscShaderProgram program) {

   116     if (program.id > 0) {

   117         asc_dprintf("Delete Shader Program %u", program.id);

   118         glDeleteProgram(program.id);

   119     }

   120     program.id = 0;

   121 }

   123 static AscShaderProgram asc_shader_compile_link_discard(

   124         char const *vtxName, char const *fragName) {

   125     AscShader font_vtx = asc_shader_compilef(GL_VERTEX_SHADER, vtxName);

   126     AscShader font_frag = asc_shader_compilef(GL_FRAGMENT_SHADER, fragName);

   127     AscShaderProgram prog = asc_shader_link(font_vtx, font_frag);

   128     asc_shader_destroy(font_vtx);

   129     asc_shader_destroy(font_frag);

   130     return prog;

   131 }

   133 void asc_shader_initialize_predefined(void) {

   134     ASC_SHADER_FONT = asc_shader_compile_link_discard("shader/font_vtx.glsl", "shader/font_frag.glsl");

   135 }

   137 void asc_shader_destroy_predefined(void) {

   138     asc_shader_program_destroy(ASC_SHADER_FONT);

   139 }

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