opengl

commit a9d199ef032c4fc563c1191850e710de89406553
parent e53186814b7da75e6f1fed69983e2fe7d60df850
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Mon, 26 Jun 2023 18:38:29 +0900

add face

Diffstat:
A
img/awesomeface.jpg
 | 
0

A
img/awesomeface.png
 | 
0

M
main.c
 | 
73
++++++++++++++++++++++++++++++++++++++++++-------------------------------
M
shaders/fragment.sl
 | 
8
+++++---
M
shaders/vertex.sl
 | 
2
--

5 files changed, 47 insertions(+), 36 deletions(-)
diff --git a/img/awesomeface.jpg b/img/awesomeface.jpg
Binary files differ.
diff --git a/img/awesomeface.png b/img/awesomeface.png
Binary files differ.
diff --git a/main.c b/main.c
@@ -12,6 +12,7 @@
 #include "stb_image.h"
 
 int rotating = 0;
+float alpha = 0.2;
 
 void
 framebuffer_size_callback(GLFWwindow *window, int width, int height)
@@ -33,6 +34,10 @@ processInput(GLFWwindow *window)
 	} else if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_RELEASE &&
 		spacePressing == 1) {
 		spacePressing = 0;
+	} else if (glfwGetKey(window, GLFW_KEY_UP) == GLFW_PRESS) {
+		alpha += 0.01;
+	} else if (glfwGetKey(window, GLFW_KEY_DOWN) == GLFW_PRESS) {
+		alpha -= 0.01;
 	}
 }
 
@@ -42,19 +47,15 @@ main(void)
 	float theta = 0;
 	float delta = 0.01;
 	float vertices[] = {
-		// positions,             colors,          texture coords
-		0.0, 0.8, 0.0,            1.0, 0.0, 0.0,   0.5, 1.0,
-		0.4*sqrtf(3), -0.4, 0.0,  0.0, 1.0, 0.0,   1.0, 0.0,
-		-0.4*sqrtf(3), -0.4, 0.0, 0.0, 0.0, 1.0,   0.0, 0.0,
+		// positions,     colors,          texture coords
+		0.5, 0.5, 0.0,    1.0, 0.0, 0.0,   1.0, 1.0,
+		-0.5, 0.5, 0.0,   0.0, 1.0, 0.0,   0.0, 1.0,
+		-0.5, -0.5, 0.0,  0.0, 0.0, 1.0,   0.0, 0.0,
+		0.5, -0.5, 0.0,   0.0, 1.0, 1.0,   1.0, 0.0,
 	};
-	float texCoords[] = {
-		0.0, 0.0,
-		1.0, 0.0,
-		0.5, 1.0,
-	};
-	
 	unsigned int indices[] = {
 		0, 1, 2,
+		0, 2, 3,
 	};	
 
 	// initialize glfw
@@ -111,27 +112,34 @@ main(void)
 		GL_STATIC_DRAW);
 	
 	// setup texture
-	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);
-	int width, height, nrChannels;
-	char *texfile = "img/wall.jpg";
-	unsigned char *data = stbi_load(texfile, &width, &height,
-		&nrChannels, 0);
-	if (data == NULL) {
-		fprintf(stderr, "can't load texture: %s\n", texfile);
-		exit(1);
+	int nTex = 2;
+	unsigned int textures[nTex];
+	char *texfiles[nTex];
+	texfiles[0] = "img/wall.jpg";
+	texfiles[1] = "img/awesomeface.jpg";
+	glGenTextures(nTex, textures);
+	for (int i = 0; i < nTex; i++) {
+		glActiveTexture(GL_TEXTURE0 + i);
+		glBindTexture(GL_TEXTURE_2D, textures[i]);
+		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);
+		int width, height;
+		unsigned char *data = stbi_load(texfiles[i], &width, &height,
+			NULL, 0);
+		if (data == NULL) {
+			fprintf(stderr, "can't load texture: %s\n", texfiles[i]);
+			exit(1);
+		}
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB,
+			GL_UNSIGNED_BYTE, data);
+		glGenerateMipmap(GL_TEXTURE_2D);
+		stbi_image_free(data);
 	}
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB,
-		GL_UNSIGNED_BYTE, data);
-	glGenerateMipmap(GL_TEXTURE_2D);
-	stbi_image_free(data);	
-		
 	while (!glfwWindowShouldClose(window)) {
 		processInput(window);
 		
@@ -142,7 +150,10 @@ main(void)
 			theta += delta;
 		}
 		ShaderSetFloat(shader, "theta", theta);
-		glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
+		glUniform1i(glGetUniformLocation(shader->ID, "texture0"), 0);
+		glUniform1i(glGetUniformLocation(shader->ID, "texture1"), 1);
+		ShaderSetFloat(shader, "alpha", alpha);
+		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
 	
 		glfwPollEvents();
 		glfwSwapBuffers(window);
diff --git a/shaders/fragment.sl b/shaders/fragment.sl
@@ -1,11 +1,13 @@
 #version 330 core
-in vec3 ourColor;
 in vec2 texCoord;
-uniform sampler2D ourTexture;
+uniform sampler2D texture0;
+uniform sampler2D texture1;
+uniform float alpha;
 out vec4 FragColor;
 
 void
 main()
 {
-	FragColor = texture(ourTexture, texCoord) * vec4(ourColor, 1.0);
+	FragColor = mix(texture(texture0, texCoord),
+		texture(texture1, 2*(vec2(1, 1)-texCoord)), alpha);
 }
diff --git a/shaders/vertex.sl b/shaders/vertex.sl
@@ -2,7 +2,6 @@
 layout (location = 0) in vec3 aPos;
 layout (location = 1) in vec3 aColor;
 layout (location = 2) in vec2 aTexCoord;
-out vec3 ourColor;
 out vec2 texCoord;
 uniform float theta;
 
@@ -12,6 +11,5 @@ main()
 	vec2 pxy = aPos.xy;
 	mat2 rot = mat2(cos(theta), -sin(theta), sin(theta), cos(theta));
 	gl_Position = vec4(pxy*rot, aPos.z, 1.0);
-	ourColor = aColor;
 	texCoord = aTexCoord;
 }