Add OpenGL 3 test program

1 files changed, 97 insertions, 0 deletions

diff --git a/test/shader_utils.h b/test/shader_utils.h
new file mode 100644
index 0000000..834d8fc
--- /dev/null
+++ b/test/shader_utils.h
@@ -0,0 +1,97 @@
+/*
+  Copyright 2019 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "glad/glad.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct
+{
+	GLuint vertexShader;
+	GLuint fragmentShader;
+	GLuint program;
+} Program;
+
+static GLuint
+compileShader(const char* source, const GLenum type)
+{
+	GLuint    shader       = glCreateShader(type);
+	const int sourceLength = (int)strlen(source);
+	glShaderSource(shader, 1, &source, &sourceLength);
+	glCompileShader(shader);
+
+	int status;
+	glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
+	if (status == GL_FALSE) {
+		GLint length;
+		glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length);
+
+		char* log = (char*)calloc(1, (size_t)length);
+		glGetShaderInfoLog(shader, length, &length, log);
+		fprintf(stderr, "error: Failed to compile shader (%s)\n", log);
+		free(log);
+
+		return 0;
+	}
+
+	return shader;
+}
+
+static void
+deleteProgram(Program program)
+{
+	glDeleteShader(program.vertexShader);
+	glDeleteShader(program.fragmentShader);
+	glDeleteProgram(program.program);
+}
+
+static Program
+compileProgram(const char* vertexSource, const char* fragmentSource)
+{
+	static const Program nullProgram = {0, 0, 0};
+
+	Program program = {compileShader(vertexSource, GL_VERTEX_SHADER),
+	                   compileShader(fragmentSource, GL_FRAGMENT_SHADER),
+	                   glCreateProgram()};
+
+	if (!program.vertexShader || !program.fragmentShader || !program.program) {
+		deleteProgram(program);
+		return nullProgram;
+	}
+
+	glAttachShader(program.program, program.vertexShader);
+	glAttachShader(program.program, program.fragmentShader);
+	glLinkProgram(program.program);
+
+	GLint status;
+	glGetProgramiv(program.program, GL_LINK_STATUS, &status);
+	if (status == GL_FALSE) {
+		GLint length;
+		glGetProgramiv(program.program, GL_INFO_LOG_LENGTH, &length);
+
+		char* log = (char*)calloc(1, (size_t)length);
+		glGetProgramInfoLog(program.program, length, &length, &log[0]);
+		fprintf(stderr, "error: Failed to link program (%s)\n", log);
+		free(log);
+
+		deleteProgram(program);
+		return nullProgram;
+	}
+
+	return program;
+}