feat: vertex and fragment shader loader implemented

7 files changed, 138 insertions, 68 deletions

diff --git a/Makefile b/Makefile
index d0240b9..5a591cc 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@ CFLAGS 	:= -Wall -Wall -pedantic -std=c11
 DLIBS 	:= $(shell pkg-config --libs glfw3 opengl glew)
 OBJDIR 	= objs
 SRCDIR  = src
-OBJS 	= $(addprefix objs/,main.o)
+OBJS 	= $(addprefix objs/,main.o shader.o)
 BIN 	= mverse
 
 all: build
diff --git a/TODO b/TODO
index 6419f4d..e9929ad 100644
--- a/TODO
+++ b/TODO
@@ -1,4 +1,4 @@
 Learning
 * Make a Hello Window
 * Make a Hello Triangle
-- Make a Shader Loader Library
+* Make a Shader Loader Library
diff --git a/shaders/fragment.vsh b/shaders/fragment.vsh
new file mode 100644
index 0000000..fcb48a4
--- /dev/null
+++ b/shaders/fragment.vsh
@@ -0,0 +1,8 @@
+#version 330 core
+in vec4 vertexColor;
+out vec4 FragColor;
+
+void main()
+{
+    FragColor = vertexColor;
+}
diff --git a/shaders/vertex.vsh b/shaders/vertex.vsh
new file mode 100644
index 0000000..d195db3
--- /dev/null
+++ b/shaders/vertex.vsh
@@ -0,0 +1,11 @@
+# version 330 core
+
+layout (location = 0) in vec3 aPos;
+
+out vec4 vertexColor;
+
+void main()
+{
+    gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0f);
+    vertexColor = vec4(0.2, 0.7, 0.2, 0.8);
+}
diff --git a/src/main.c b/src/main.c
index 2d296a8..af2c65a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -6,24 +6,9 @@
 #include <GL/glew.h>
 #include <GLFW/glfw3.h>
 
+#include "shader.h"
 #include "main.h"
 
-const char *vertexShaderSource = \
-"#version 330 core\n"
-"layout (location = 0) in vec3 aPos;\n"
-"void main()\n"
-"{\n"
-"   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
-"}\0";
-
-const char *fragmentShaderSource = \
-"#version 330 core\n"
-"out vec4 FragColor;\n"
-"void main()\n"
-"{\n"
-"   FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
-"}\0";
-
 float vertices[] = {
     -0.5f, -0.5f, 0.0f,
     0.5f, -0.5f, 0.0f,
@@ -34,7 +19,6 @@ float vertices[] = {
 static void userError(const char *msg, const char *detail);
 static void glfw_size_callback(GLFWwindow *window, int width, int height);
 static void processInput(GLFWwindow *window, struct Background *c);
-static void checkGLSuccess(unsigned int compiledShader, unsigned int shaderStep);
 
 void 
 userError(const char *msg, const char *detail)
@@ -64,34 +48,6 @@ processInput(GLFWwindow *window, struct Background *c)
     } 
 }
 
-void 
-checkGLSuccess(unsigned int shaderBinary, unsigned int shaderStep)
-{
-    int success;
-    char infoLog[512];
-    switch (shaderStep) {
-        case 0:
-            glGetShaderiv(shaderBinary, GL_COMPILE_STATUS, &success);
-            if (!success) {
-                glGetShaderInfoLog(shaderBinary, 512, NULL, infoLog);
-                userError("glCompileShader() ERROR", infoLog);
-            }
-            break;
-
-        case 1:
-            glGetProgramiv(shaderBinary, GL_LINK_STATUS, &success);
-
-            if (!success) {
-                glGetProgramInfoLog(shaderBinary, 512, NULL, infoLog);
-                userError("glLinkProgram() ERROR", infoLog);
-            }
-            break;
-
-        default:
-            break;
-    }
-}
-
 int main()
 {
     GLFWwindow *window;
@@ -125,32 +81,18 @@ int main()
     glBindVertexArray(VAO);
 
     glGenBuffers(1, &VBO);
+
     glBindBuffer(GL_ARRAY_BUFFER, VBO);
     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
     glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void *)0);
     glEnableVertexAttribArray(0);
 
-    unsigned int vertexShader, fragmentShader, shaderProgram;
-    vertexShader = glCreateShader(GL_VERTEX_SHADER);
-    glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
-    glCompileShader(vertexShader);
-    checkGLSuccess(vertexShader, 0);
-    printf("Vertex Compiled\n");
-
-    fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
-    glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
-    glCompileShader(fragmentShader);
-    checkGLSuccess(fragmentShader, 0);
-    printf("Fragment Compiled\n");
-
-    shaderProgram = glCreateProgram();
-    glAttachShader(shaderProgram, vertexShader);
-    glAttachShader(shaderProgram, fragmentShader);
-    glLinkProgram(shaderProgram);
-    checkGLSuccess(shaderProgram, 1);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
 
-    glDeleteShader(vertexShader);
-    glDeleteShader(fragmentShader);
+    unsigned int shaderProgram = shaderCreateProgram("shaders/vertex.vsh", 
+                                                     "shaders/fragment.vsh");
 
     while (!glfwWindowShouldClose(window)) {
         processInput(window, &colors);
@@ -160,12 +102,14 @@ int main()
 
         glUseProgram(shaderProgram);
         glBindVertexArray(VAO);
-        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
         glDrawArrays(GL_TRIANGLES, 0, 3);
 
         glfwSwapBuffers(window);
         glfwPollEvents();
     }
+    int nattributes;
+    glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, &nattributes);
+    printf("%d\n", nattributes);
     glfwTerminate();
     return 0;
 }
diff --git a/src/shader.c b/src/shader.c
new file mode 100644
index 0000000..e21277f
--- /dev/null
+++ b/src/shader.c
@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <GL/glew.h>
+#include "shader.h"
+
+static char *getShaderSource(const char *shaderPath);
+static void checkShaderCompile(unsigned int shader, const char *shaderPath);
+static void checkProgramLink(unsigned int shader);
+
+char
+*getShaderSource(const char *shaderPath)
+{
+    long fileSize;
+    char *shaderSource;
+    FILE *shaderFile = fopen(shaderPath, "r");
+
+    if (!shaderFile) {
+        perror("getShaderSource() ERROR");
+        exit(1);
+    }
+
+    fseek(shaderFile, 0L, SEEK_END);
+    fileSize = ftell(shaderFile);
+    if (!fileSize) {
+        fprintf(stderr, "getShaderSource() ERROR: %s file is empty\n", shaderPath);
+        exit(1);
+    }
+
+    rewind(shaderFile);
+
+    shaderSource = malloc(fileSize * sizeof(char));
+    if (!fscanf(shaderFile, "%[^\\]", shaderSource)) {
+        perror("getShaderSource() ERROR");
+        exit(1);
+    }
+
+    fclose(shaderFile);
+    return shaderSource;
+}
+
+void
+checkShaderCompile(unsigned int shader, const char *shaderPath)
+{
+    int success;
+    char infoLog[512];
+
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
+    if (!success) {
+        glGetShaderInfoLog(shader, 512, NULL, infoLog);
+        fprintf(stderr, "shaderCompile() ERROR\n%s %s\n", shaderPath, infoLog);
+        exit(1);
+    }
+}
+
+void
+checkProgramLink(unsigned int shaderProgram)
+{
+    int success;
+    char infoLog[512];
+    glLinkProgram(shaderProgram);
+    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
+    if (!success) {
+        glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
+        fprintf(stderr, "shaderProgramLink() ERROR\n%s\n", infoLog);
+        exit(1);
+    }
+}
+
+unsigned int
+shaderCreateProgram(const char *vertexShaderPath, const char *fragmentShaderPath)
+{
+    unsigned int vertexShader, fragmentShader, shaderProgram;
+    char *vertexShaderSource, *fragmentShaderSource;
+
+    vertexShader = glCreateShader(GL_VERTEX_SHADER);
+    fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
+
+    vertexShaderSource = getShaderSource(vertexShaderPath);
+    fragmentShaderSource = getShaderSource(fragmentShaderPath);
+
+    glShaderSource(vertexShader, 1, (const char **)&vertexShaderSource, NULL);
+    glCompileShader(vertexShader);
+    checkShaderCompile(vertexShader, vertexShaderPath);
+
+    glShaderSource(fragmentShader, 1, (const char **)&fragmentShaderSource, NULL);
+    glCompileShader(fragmentShader);
+    checkShaderCompile(fragmentShader, fragmentShaderPath);
+
+    shaderProgram = glCreateProgram();
+    glAttachShader(shaderProgram, vertexShader);
+    glAttachShader(shaderProgram, fragmentShader);
+    glLinkProgram(shaderProgram);
+    checkProgramLink(shaderProgram);
+
+    glDeleteShader(vertexShader);
+    glDeleteShader(fragmentShader);
+    free(vertexShaderSource);
+    free(fragmentShaderSource);
+
+    return shaderProgram;
+}
diff --git a/src/shader.h b/src/shader.h
new file mode 100644
index 0000000..5f1e315
--- /dev/null
+++ b/src/shader.h
@@ -0,0 +1,5 @@
+#ifndef __SHADER__
+#define __SHADER__
+
+unsigned int shaderCreateProgram(const char *vertexShaderPath, const char *fragmentShaderPath);
+#endif