opengl

commit 59fbab53ee580386a1601fea22d01f39ef861113
parent d295d2de6f1c23fc2da63688f028e445dc1449d6
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Sun, 25 Jun 2023 17:50:35 +0900

divide shaders to separate files

Diffstat:
M
main.c
 | 
83
+++++++++++++++++++++++++++++++++++++++++++++++--------------------------------
A
shaders/fragment.sl
 | 
9
+++++++++
A
shaders/vertex.sl
 | 
11
+++++++++++

3 files changed, 70 insertions(+), 33 deletions(-)
diff --git a/main.c b/main.c
@@ -1,6 +1,8 @@
+#include <errno.h>
+#include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <math.h>
+#include <string.h>
 
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
@@ -23,9 +25,48 @@ typedef struct Shader {
 	unsigned int ID;
 } Shader;
 
+// Readfile read from file to a char* and return that pointer.
+// Caller is responsible to free the returned pointer.
+char *
+readfile(const char *file)
+{
+	FILE *f = fopen(file, "r");
+	if (f == NULL) {
+		snprintf(errstr, sizeof(errstr), "fopen: errno = %d", errno);
+		return NULL;
+	}
+	
+	size_t bufsize = 1024;
+	char *c;
+	c = (char *)malloc(bufsize);
+	
+	size_t read = fread(c, sizeof(c[0]), bufsize, f);
+	if (read == sizeof(c)) {
+		snprintf(errstr, sizeof(errstr),
+			"read file: file too big: %s", file);
+		return NULL;
+	}
+	return c;
+}
+
 Shader *
-ShaderInit(const char *vertexShaderSource, const char *fragmentShaderSource)
+ShaderInit(const char *vs, const char *fs)
 {
+	char *vertexShaderSource = readfile(vs);
+	if (vertexShaderSource == NULL) {
+		char *olderr = strdup(errstr);
+		snprintf(errstr, sizeof(errstr),
+			"read vertex shader: %s", olderr);
+		return NULL;
+	}
+	char *fragmentShaderSource = readfile(fs);
+	if (vertexShaderSource == NULL) {
+		char *olderr = strdup(errstr);
+		snprintf(errstr, sizeof(errstr),
+			"read fragment shader: %s", olderr);
+		return NULL;
+	}
+	
 	unsigned int vertexShader;
 	int success;
 	char log[512];
@@ -36,7 +77,7 @@ ShaderInit(const char *vertexShaderSource, const char *fragmentShaderSource)
 	if (!success) {
 		glGetShaderInfoLog(vertexShader, sizeof(log), NULL, log);
 		snprintf(errstr, sizeof(errstr),
-			"compile vertex shader: %s\n", log);
+			"compile vertex shader: %s", log);
 		return NULL;
 	}
 	unsigned int fragmentShader;
@@ -47,7 +88,7 @@ ShaderInit(const char *vertexShaderSource, const char *fragmentShaderSource)
 	if (!success) {
 		glGetShaderInfoLog(fragmentShader, sizeof(log), NULL, log);
 		snprintf(errstr, sizeof(errstr),
-			"compile fragment shader: %s\n", log);
+			"compile fragment shader: %s", log);
 		return NULL;
 	}
 	unsigned int shaderProgram;
@@ -59,9 +100,12 @@ ShaderInit(const char *vertexShaderSource, const char *fragmentShaderSource)
 	if (!success) {
 		glGetShaderInfoLog(shaderProgram, sizeof(log), NULL, log);
 		snprintf(errstr, sizeof(errstr),
-			"link shaders: %s\n", log);
+			"link shaders: %s", log);
 		return NULL;
 	}
+	
+	free(vertexShaderSource);
+	free(fragmentShaderSource);
 	glDeleteShader(vertexShader);
 	glDeleteShader(fragmentShader);
 	
@@ -80,33 +124,6 @@ ShaderDelete(Shader *s) {
 	glDeleteProgram(s->ID);
 }
 
-const char *vertexShaderSource = "
-	#version 330 core
-	layout (location = 0) in vec3 aPos;
-	layout (location = 1) in vec3 aColor;
-	out vec3 ourColor;
-	
-	void
-	main()
-	{
-		gl_Position = vec4(aPos, 1.0);
-		ourColor = aColor;
-	}
-";
-
-const char *fragmentShaderSource = "
-	#version 330 core
-	in vec3 ourColor;
-	out vec4 FragColor;
-	
-	void
-	main()
-	{
-		FragColor = vec4(ourColor, 1.0);
-	}
-";
-
-
 void
 framebuffer_size_callback(GLFWwindow *window, int width, int height)
 {
@@ -148,7 +165,7 @@ main(void)
 	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 	
 	// setup shaders
-	Shader *shader = ShaderInit(vertexShaderSource, fragmentShaderSource);
+	Shader *shader = ShaderInit("shaders/vertex.sl", "shaders/fragment.sl");
 	if (shader == NULL) {
 		fprintf(stderr, "init shader: %s\n", errstr);
 		exit(1);
diff --git a/shaders/fragment.sl b/shaders/fragment.sl
@@ -0,0 +1,9 @@
+#version 330 core
+in vec3 ourColor;
+out vec4 FragColor;
+
+void
+main()
+{
+	FragColor = vec4(ourColor, 1.0);
+}
diff --git a/shaders/vertex.sl b/shaders/vertex.sl
@@ -0,0 +1,11 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aColor;
+out vec3 ourColor;
+
+void
+main()
+{
+	gl_Position = vec4(aPos, 1.0);
+	ourColor = aColor;
+}