opengl

commit 524c505d628c280f14aa75ac90dad65967d72c12
parent c4f54ac8aff3b3c3590f61052940dbf529aca328
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Wed, 28 Jun 2023 07:02:15 +0900

implement translation

Diffstat:
M
glm.c
 | 
39
++++++++++++++++++++++++++++++++++++---
M
glm.h
 | 
3
+++
M
main.c
 | 
14
+++++++-------

3 files changed, 46 insertions(+), 10 deletions(-)
diff --git a/glm.c b/glm.c
@@ -101,6 +101,23 @@ vecCross(vec *v, const vec *w)
 	return v;
 }
 
+char *
+matStr(char *s, mat *m)
+{
+	int cur = 0;
+	for (int i = 0; i < m->size; i++) {
+		for (int j = 0; j < m->size; j++) {
+			cur += sprintf(&s[cur], "%2.2f%s", m->data[i+m->size*j],
+				j == m->size-1 ? "" : " ");
+		}
+		if (i != m->size - 1) {
+			cur += sprintf(&s[cur], "\n");
+		}
+	}
+	sprintf(&s[cur], "\n\0");
+	return s;
+}
+
 mat *
 matMake(float *data, int size)
 {
@@ -113,6 +130,18 @@ matMake(float *data, int size)
 	return m;
 }
 
+mat *
+matMakeIdent(int size)
+{
+	mat *m = (mat *)malloc(sizeof(mat));
+	m->data = (float *)calloc(sizeof(float), size*size);
+	for (int i = 0; i < size; i++) {
+		m->data[i + size*i] = 1;
+	}
+	m->size = size;
+	return m;
+}
+
 void
 matFree(mat *m)
 {
@@ -151,15 +180,19 @@ matDot(mat *m, const mat *n) // m_ij = m->data[i + m->size*j]
 mat *
 translate(mat *m, const vec *v)
 {
-	return NULL;
+	if (m->size != 4 || v->size != 3)
+		assert(!"mat size must be 4 and vec size must be 3");
+	m->data[12] += v->data[0];
+	m->data[13] += v->data[1];
+	m->data[14] += v->data[2];
+	return m;
 }
 
 mat *
 rotate(mat *m, float rad, vec *axis)
 {
-	if (axis->size != 3) {
+	if (axis->size != 3)
 		assert(!"axis size must be 3");
-	}
 	float x = axis->data[0];
 	float y = axis->data[1];
 	float z = axis->data[2];
diff --git a/glm.h b/glm.h
@@ -25,9 +25,12 @@ vec *vecSub(vec *v, const vec *w);
 float vecDot(const vec *v, const vec *w);
 vec *vecCross(vec *v, const vec *w);
 
+char *matStr(char *s, mat *m);
 mat *matMake(float *data, int size);
+mat *matMakeIdent(int size);
 void matFree(mat *m);
 float *matDataPtr(mat *m);
 
 mat *translate(mat *m, const vec *v);
+// axis must be an unit vector
 mat *rotate(mat *m, float rad, vec *axis);
diff --git a/main.c b/main.c
@@ -66,11 +66,8 @@ main(void)
 		0, 3, 5,
 		0, 4, 5,
 	};
-	mat *trans = matMake((float[]){1.0, 0.0, 0.0, 0.0,
-		0.0, 1.0, 0.0, 0.0,
-		0.0, 0.0, 1.0, 0.0,
-		0.0, 0.0, 0.0, 1.0,}, 4);
-	vec *axis = vecMake((float[]){1.0, 1.0, 0.0}, 3);
+	vec *axis = vecMake((float[]){1.41421356/2, 1.41421356/2, 0.0}, 3);
+	vec *transvec = vecMake((float[]){0.5, -0.5, 0.0}, 3);
 	
 	// initialize glfw
 	glfwInit();
@@ -152,27 +149,30 @@ main(void)
 		stbi_image_free(data);
 	}
 	
+	
 	while (!glfwWindowShouldClose(window)) {
 		processInput(window);
 		
 		glClearColor(1.0, 1.0, 0.8, 1.0);
 		glClear(GL_COLOR_BUFFER_BIT);
 		
+		mat *trans = matMakeIdent(4);
 		if (rotating) {
-			rotate(trans, delta, axis);
+			rotate(trans, (float)glfwGetTime(), axis);
 		}
+		translate(trans, transvec);
 		ShaderSetFloat(shader, "alpha", alpha);
 		glUniform1i(glGetUniformLocation(shader->ID, "texture0"), 0);
 		glUniform1i(glGetUniformLocation(shader->ID, "texture1"), 1);
 		unsigned int tloc = glGetUniformLocation(shader->ID, "transform");
 		glUniformMatrix4fv(tloc, 1, GL_FALSE, matDataPtr(trans));
 		glDrawElements(GL_TRIANGLES, 12, GL_UNSIGNED_INT, 0);
+		matFree(trans);
 	
 		glfwPollEvents();
 		glfwSwapBuffers(window);
 	}
 	
-	matFree(trans);
 	vecFree(axis);
 
 	glDeleteVertexArrays(1, &VAO);