Map a texture to the triangles.

src/fragment.glsl

@@ -1,8 +1,12 @@
 // Set the GLSL version to 3.3 and use the OpenGL core profile
 #version 330 core
 out vec4 FragColor;
+
 in vec3 ourColor;
+in vec2 TexCoord;
+
+uniform sampler2D ourTexture;
 
 void main() {
-	FragColor = vec4(ourColor, 1.0);
+	FragColor = texture(ourTexture, TexCoord);
 }

src/image.cc

@@ -0,0 +1,10 @@
+#include "image.hh"
+#include <stb/stb_image.h>
+
+Image::Image(const char* path) {
+	data = stbi_load(path, &width, &height, &nrChannels, 0);
+}
+
+Image::~Image() {
+	stbi_image_free(data);
+}

src/image.hh

@@ -0,0 +1,11 @@
+#ifndef IMAGE_HH
+#define IMAGE_HH
+#define STB_IMAGE_IMPLEMENTATION
+class Image {
+	public:
+		int width, height, nrChannels;
+		unsigned char* data;
+		Image(const char* path);
+		~Image();
+};
+#endif

src/main.cc

@@ -6,6 +6,7 @@
 
 #include "shader.hh"
 #include "utilities.hh"
+#include "image.hh"
 
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void process_input(GLFWwindow* window);
@@ -34,10 +35,10 @@ struct GlRenderObjects {
 GlRenderObjects* triangle() {
 	// An array of verticies containing data for a triangle.
 	float vertices[] = {
-		// positions		// colors
-		-0.5f, -0.5f, 0.0f,	1.0f, 0.0f, 0.0f,
-		0.5f, -0.5f, 0.0f,	0.0f,1.0f, 0.0f,
-		0.0f, 0.5f,  0.0f,	0.0f, 0.0f, 1.0f
+		// positions		// colors		// texture coords
+		-0.5f, -0.5f, 0.0f,	1.0f, 0.0f, 0.0f,	1.0f, 1.0f,
+		0.5f, -0.5f, 0.0f,	0.0f,1.0f, 0.0f,	1.0f, 0.0f,
+		0.0f, 0.5f,  0.0f,	0.0f, 0.0f, 1.0f,	0.0f, 0.0f
 	};
 
 	unsigned int vertexBufferObject, vertexArrayObject;
@@ -58,14 +59,18 @@ GlRenderObjects* triangle() {
 	// This will pass the position attribute to the location "0". We tell OpenGL the size of each position attribute is 3 floats.
 	// We tell OpenGL that we're using floating point types.
 	// We tell OpenGL we don't want our data to be normalized as its already normalized.
-	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
 	glEnableVertexAttribArray(0);
 
 	// Pass the color attribute data to the location 1.
 	// We tell it to offset the data per "vertex" by 3 floats to get the color data instead of the position data.
-	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3*sizeof(float)));
+	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3*sizeof(float)));
 	glEnableVertexAttribArray(1);
 
+	// Process the texture coord data.
+	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)(6 * sizeof(float)));
+	glEnableVertexAttribArray(2);
+
 	glBindBuffer(GL_ARRAY_BUFFER, 0);
 	glBindVertexArray(0);
 
@@ -74,11 +79,11 @@ GlRenderObjects* triangle() {
 
 GlRenderObjects* rectangle() {
 	float vertices[] = {
-		// positions		// colors
-		0.5f,  0.5f, 0.0f,	1.0f, 0.0f, 0.0f,
-		0.5f, -0.5f, 0.0f,	0.0f,1.0f, 0.0f,
-		-0.5f, -0.5f, 0.0f,	0.0f, 0.0f, 1.0f,
-		-0.5f,  0.5f, 0.0f,	1.0f, 0.0f, 1.0f
+		// positions		// colors		// texture coords
+		0.5f,  0.5f, 0.0f,	1.0f, 0.0f, 0.0f,	1.0f, 1.0f,
+		0.5f, -0.5f, 0.0f,	0.0f,1.0f, 0.0f,	1.0f, 0.0f,
+		-0.5f, -0.5f, 0.0f,	0.0f, 0.0f, 1.0f,	0.0f, 0.0f,
+		-0.5f,  0.5f, 0.0f,	1.0f, 0.0f, 1.0f,	0.0f, 1.0f
 	};
 
 	unsigned int indices[] = {
@@ -107,13 +112,17 @@ GlRenderObjects* rectangle() {
 	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
 
 	// Tell OpenGL on how to process the verticies.
-	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void *)0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)0);
 	glEnableVertexAttribArray(0);
 
 	// Process the color data.
-	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void *)(3*sizeof(float)));
+	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)(3*sizeof(float)));
 	glEnableVertexAttribArray(1);
 
+	// Process the texture coord data.
+	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)(6 * sizeof(float)));
+	glEnableVertexAttribArray(2);
+
 	// Unbind the current buffers and arrays from the state.
 	glBindBuffer(GL_ARRAY_BUFFER, 0);
 	glBindVertexArray(0);
@@ -158,6 +167,25 @@ int main() {
 	GlRenderObjects* triangleRenderObjs = triangle();
 	GlRenderObjects* rectangleRenderObjs = rectangle();
 
+	unsigned int texture;
+	glGenTextures(1, &texture);
+	glBindTexture(GL_TEXTURE_2D, texture);
+
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+	{
+		Image texture(std::format("{}/container.jpg", utilities::getCurrentPath()).c_str());
+		if (texture.data) {
+			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, texture.width, texture.height, 0, GL_RGB, GL_UNSIGNED_BYTE, texture.data);
+			glGenerateMipmap(GL_TEXTURE_2D);
+		} else {
+			std::cout << "Failed to load texture." << std::endl;
+		}
+	}
+
 	// Create a render loop, which keeps the program open until glfw tells the loop that the window should close.
 	while (!glfwWindowShouldClose(window)) {
 		// Process input.

src/meson.build

@@ -1,14 +1,15 @@
 sources = [
 	'main.cc',
 	'shader.cc',
-	'utilities.cc'
+	'utilities.cc',
+	'image.cc'
 ]
 
 copy = find_program('cp')
 
 fragment = custom_target('fragment', output: 'fragment.glsl', input: 'fragment.glsl', command: [copy, '@INPUT@', '@OUTPUT@'])
 vertex = custom_target('vertex', output: 'vertex.glsl', input: 'vertex.glsl', command: [copy, '@INPUT@', '@OUTPUT@'])
+container = custom_target('container', output: 'container.jpg', input: 'container.jpg', command: [copy, '@INPUT@', '@OUTPUT@'])
 
-
-executable('main', [sources] + [fragment, vertex], dependencies: [glfw, libepoxy])
+executable('main', [sources] + [fragment, vertex, container], dependencies: [glfw, libepoxy])
 executable('fixedfunction', ['fixedfunction.cc'], dependencies: [glfw, libepoxy])

src/vertex.glsl

@@ -2,9 +2,13 @@
 #version 330 core
 layout (location = 0) in vec3 aPos;
 layout (location = 1) in vec3 aColor;
+layout (location = 2) in vec2 aTexCoord;
+
 out vec3 ourColor;
+out vec2 TexCoord;
 
 void main() {
 	gl_Position = vec4(aPos, 1.0);
 	ourColor = aColor;
+	TexCoord = aTexCoord;
 }