commit 5a042628ae2bc2d756d79631e23ddd54ede5d555
parent 542affc01b82be365dcf7252a659c28bc7094368
Author: mjkloeckner <martin.cachari@gmail.com>
Date: Thu, 29 Dec 2022 02:06:35 -0300
load shaders from file
added main.frag and main.vert which are files which contain the fragment
shaders source and vertex shaders source respectively
the shaders source is loaded into a variable with a new function in
main.c (loadShaderFromFile)
Diffstat:
| M | main.c | | | 88 | +++++++++++++++++++++++++++++++++++++++++++++++-------------------------------- |
| A | main.frag | | | 6 | ++++++ |
| A | main.vert | | | 6 | ++++++ |
3 files changed, 64 insertions(+), 36 deletions(-)
diff --git a/main.c b/main.c
@@ -4,39 +4,59 @@
#include <stdio.h>
-#define WINDOW_TITLE "OpenGL Test Window"
-#define WINDOW_WIDTH 800
-#define WINDOW_HEIGHT 600
+#define WIN_TITLE "OpenGL Test Window"
+#define WIN_WIDTH 800
+#define WIN_HEIGHT 600
+
+#define FRAGMENT_SHADER_FILE_NAME "main.frag"
+#define VERTEX_SHADER_FILE_NAME "main.vert"
void glfwPrintError(int e, const char *s) {
fprintf(stderr, "%s\n", s);
}
+char *loadShaderFromFile(const char *filename) {
+ char *buffer;
+ long len;
+ FILE *f = fopen(filename, "rb");
+
+ if(f) {
+ fseek(f, 0, SEEK_END);
+ len = ftell(f);
+ fseek(f, 0, SEEK_SET);
+ buffer = (char *)malloc(len + 1);
+ buffer[len] = '\0';
+
+ if(buffer)
+ fread (buffer, 1, len, f);
+
+ fclose (f);
+ } else return NULL;
+
+ return buffer;
+}
+
int main (void) {
GLenum err;
+ GLFWwindow *win;
+ unsigned int VBO, VAO; /* Vertex Buffer Objects, Vertex Array Objects */
+ const char *vertexShaderSource, *fragmentShaderSource;
+ unsigned int vertexShader, fragmentShader, shaderProgram;
+ int success;
+ char infoLog[512];
if(!glfwInit()) {
fprintf(stderr, "GLFW: failed to initialize\n");
return 1;
}
- glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
- glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
-
- GLFWwindow *win = glfwCreateWindow(WINDOW_WIDTH, WINDOW_HEIGHT,
- WINDOW_TITLE, NULL, NULL);
-
- if(!win) {
- fprintf(stderr, "GLFW: failed to create window\n");
+ if(!(win = glfwCreateWindow(WIN_WIDTH, WIN_HEIGHT, WIN_TITLE, NULL, NULL)))
glfwTerminate();
- }
glfwSetErrorCallback(&glfwPrintError);
-
glfwMakeContextCurrent(win);
-
- if((err = glewInit()) != 0) {
+ if((err = glewInit())) {
fprintf(stderr, "GLEW: %s\n", glewGetErrorString(err));
return 2;
}
@@ -48,10 +68,11 @@ int main (void) {
0.0f, 0.5f, 0.0f,
};
- unsigned int VBO; /* Vertex Buffer Objects */
- glGenBuffers(1, &VBO); /* Generate an unique ID to VBO */
- glBindBuffer(GL_ARRAY_BUFFER, VBO); /* bind VBO to a Vertex Buffer type */
+ /* Generate an unique ID to VBO */
+ glGenBuffers(1, &VBO);
+ /* Bind VBO to a Vertex Buffer type */
+ glBindBuffer(GL_ARRAY_BUFFER, VBO);
/* Copy the previously defined Vertex Data (vertices) into the buffer's
* memory.
@@ -63,20 +84,17 @@ int main (void) {
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
/* Vertex Shader */
- const char *vertexShaderSource = "#version 410 core\n"
- "layout (location = 0) in vec3 aPos;\n"
- "void main() {\n"
- " gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
- "}\0";
+ if(!(vertexShaderSource = loadShaderFromFile(VERTEX_SHADER_FILE_NAME))) {
+ fprintf(stderr, "could not load shader from file \"%s\n\"",
+ VERTEX_SHADER_FILE_NAME);
+ return 1;
+ }
- unsigned int vertexShader;
vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
/* Check if the Vertex Shader compiled succesfully */
- int success;
- char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if(!success) {
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
@@ -85,13 +103,12 @@ int main (void) {
}
/* Fragment Shader */
- const char *fragmentShaderSource = "#version 410 core\n"
- "out vec4 fragColor;\n"
- "void main() {\n"
- "fragColor = vec4(1.0f, 0.0f, 0.0f, 1.0f);\n"
- "}\n";
+ if(!(fragmentShaderSource = loadShaderFromFile(FRAGMENT_SHADER_FILE_NAME))) {
+ fprintf(stderr, "could not load shader from file \"%s\n\"",
+ FRAGMENT_SHADER_FILE_NAME);
+ return 1;
+ }
- unsigned int fragmentShader;
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glCompileShader(fragmentShader);
@@ -105,9 +122,7 @@ int main (void) {
}
/* Shader Program */
- unsigned int shaderProgram;
shaderProgram = glCreateProgram();
-
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
@@ -124,8 +139,6 @@ int main (void) {
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
-
- unsigned int VAO;
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
@@ -145,5 +158,8 @@ int main (void) {
glfwPollEvents();
}
+ free(vertexShaderSource);
+ free(fragmentShaderSource);
+ glfwTerminate();
return 0;
}
diff --git a/main.frag b/main.frag
@@ -0,0 +1,6 @@
+#version 410 core
+out vec4 fragColor;
+
+void main() {
+ fragColor = vec4(1.0f, 0.0f, 0.0f, 1.0f);
+}
diff --git a/main.vert b/main.vert
@@ -0,0 +1,6 @@
+#version 410 core
+layout (location = 0) in vec3 aPos;
+
+void main() {
+ gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);
+}
