Added OpenGL boilerplate

1 files changed, 73 insertions, 0 deletions

diff --git a/src/shader.c b/src/shader.c
new file mode 100644
index 0000000..478c93b
--- /dev/null
+++ b/src/shader.c
@@ -0,0 +1,73 @@
+#include "mandel.h"
+
+#define MANDEL_SHADER_VERT_FILE "shader/vertex.glsl"
+#define MANDEL_SHADER_FRAG_FILE "shader/fragment.glsl"
+
+static unsigned int	st_compile(char *filepath, unsigned int type);
+
+bool				shader_init(Shader *shader)
+{
+	unsigned int	shader_vert;
+	unsigned int	shader_frag;
+
+	shader_vert = st_compile(MANDEL_SHADER_VERT_FILE, GL_VERTEX_SHADER);
+	if (shader_vert == 0)
+		return false;
+	shader_frag = st_compile(MANDEL_SHADER_FRAG_FILE, GL_FRAGMENT_SHADER);
+	if (shader_frag == 0)
+		return false;
+
+	GL_CALL(shader->id = glCreateProgram());
+	GL_CALL(glAttachShader(shader->id, shader_vert));
+	GL_CALL(glAttachShader(shader->id, shader_frag));
+	GL_CALL(glLinkProgram(shader->id));
+	GL_CALL(glValidateProgram(shader->id));
+	GL_CALL(glDeleteShader(shader_vert));
+	GL_CALL(glDeleteShader(shader_frag));
+	return (true);
+}
+
+static unsigned int	st_compile(char *filepath, unsigned int type)
+{
+	unsigned int	id;
+	int				result;
+	FILE			*file;
+	char			*source;
+
+	if ((file = fopen(filepath, "r")) == NULL)
+		return 0;
+	fseek(file, 0, SEEK_END);
+	long file_size = ftell(file);
+	rewind(file);
+
+	if ((source = malloc(sizeof(char) * (file_size + 1))) == NULL
+		|| fread(source, sizeof(char), file_size, file) != (unsigned long)file_size)
+	{
+		free(source);
+		fclose(file);
+		return 0;
+	}
+	fclose(file);
+	source[file_size] = '\0';
+
+	GL_CALL(id = glCreateShader(type));
+	GL_CALL(glShaderSource(id, 1, (const char**)&source, (int*)&file_size));
+	free(source);
+	GL_CALL(glCompileShader(id));
+
+	GL_CALL(glGetShaderiv(id, GL_COMPILE_STATUS, &result));
+	if (result == GL_FALSE)
+	{
+		int		len;
+		char	*msg;
+		GL_CALL(glGetShaderiv(id, GL_INFO_LOG_LENGTH, &len));
+		if ((msg = malloc(sizeof(char) * (len + 1))) == NULL)
+			return 0;
+		GL_CALL(glGetShaderInfoLog(id, len, &len, msg));
+		fputs(msg, stderr);
+		free(msg);
+		GL_CALL(glDeleteShader(id));
+		return 0;
+	}
+	return id;
+}